Libido 7 by Jobacom B.V.

EFFECTIVE

• Dyspepsia. Oral calcium carbonate is approved by the US Food and Drug Administration (FDA) as an antacid. Details: Taking calcium carbonate orally as an antacid is effective for treating dyspepsia (1843). Calcium carbonate has FDA approval as an antacid.
• Hyperkalemia. Intravenous calcium gluconate is approved by the US Food and Drug Administration (FDA) for preventing hyperkalemia-induced cardiac abnormalities. Details: Administering calcium gluconate intravenously can reverse electrocardiographic changes and arrhythmias induced by hyperkalemia (12946). Intravenous calcium gluconate is FDA-approved for preventing hyperkalemia-induced cardiac abnormalities.
• Hypocalcemia. Oral calcium treats and prevents hypocalcemia. Intravenous calcium is used to treat severe hypocalcemia. Details: Taking calcium orally is effective for treating and preventing hypocalcemia. Intravenous calcium gluconate, acetate, gluceptate, or chloride is effective for severe hypocalcemia or hypocalcemic tetany (12928).
• Kidney failure. Oral calcium carbonate or calcium acetate is used as a phosphate binder during kidney failure. Details: Taking calcium carbonate or calcium acetate orally is effective as a phosphate binder. Calcium acetate (PhosLo) appears to control hyperphosphatemia better than sevelamer (Renagel) (12943,12944,38990). Calcium citrate is not recommended for this purpose because it increases aluminum absorption and does not bind phosphate as efficiently as calcium acetate or calcium carbonate (21631). Some clinical research also shows that taking calcium orally reduces blood pressure in patients with kidney failure (975).

LIKELY EFFECTIVE

• Corticosteroid-induced osteoporosis. Oral calcium in combination with vitamin D prevents bone density loss that occurs during long-term treatment with corticosteroids. Details: Taking calcium in combination with vitamin D as adjunctive therapy seems to be effective for reducing bone mineral density loss in people using corticosteroids long-term (982,1046,1830,1831,1832,4462,4463,4464,4465,4466)(4467,12945,38493). One specific product used in clinical research is Oscal (Marion Merrel Dow Inc.), which contains elemental calcium 500 mg per tablet plus vitamin D 125 IU per tablet (982). Another product used is Oscal 250 + D (SmithKline Beecham Healthcare), which contains elemental calcium 250 mg and vitamin D 125 IU per tablet (1046).
• Hyperparathyroidism. Oral calcium reduces parathyroid hormone levels in patients with secondary hyperparathyroidism due to kidney failure. Details: Taking calcium orally reduces parathyroid hormone levels in patients with kidney failure and secondary hyperparathyroidism (1827,1828,1829,39174,39425). In elderly women, the combination of calcium and vitamin D reverses secondary hyperparathyroidism and reduces hip fracture risk (8818). Also, population research suggests increased calcium intake from the diet and supplements reduces the risk of primary hyperparathyroidism in women. Supplemental intakes of at least 500 mg/day and dietary intakes of approximately 1100 mg/day are considered to be protective (91353).
• Osteoporosis. Adequate calcium intake, from the diet and/or supplements, is recommended for the prevention and treatment of osteoporosis. Details: The Bone Health and Osteoporosis Foundation (BHOF) recommends ensuring adequate calcium intake in line with the recommended dietary allowance (RDA) by age, along with adequate vitamin D intake, for the prevention and treatment of osteoporosis in adults over 50 years of age. Supplementation can be used to augment dietary intake when adequate dietary intake is not feasible (109425). In the US and Canada, foods containing at least 200 mg calcium with less phosphorous content than calcium can be labelled with a health claim regarding the relationship between adequate calcium intake and a reduced risk for osteoporosis (11940,102148). However, calcium supplementation is not recommended specifically for the primary prevention of osteoporosis. The US Preventive Task Force (USPSTF) states that the current evidence is insufficient to assess the balance of benefits and harms of vitamin D and calcium supplementation, alone or in combination, for the primary prevention of fractures in community dwelling adults without osteoporosis (95695). Also, calcium supplements do not seem to be effective for preventing loss of bone mineral density (BMD) during lactation (988), in patients who have had bone marrow transplantation (1817), or in patients who have had renal transplantation (4823,38736,38871). Maximal bone growth occurs in the teenage years, and then BMD in females remains relatively constant until age 30-40. After age 40, bone loss typically occurs at rates of 0.5% to 1% per year. In males, this occurs several decades later. Bone loss is more pronounced if dietary calcium intake is below the RDA, which is the case for many Americans (2571,2578). One meta-analysis of randomized controlled trials in healthy children 7-14 years old shows that fortifying food with calcium 250-1000 mg daily for up to 24 months modestly improves femoral neck BMD, but not hip or spine BMD. However, the included trials did not supplement vitamin D (107232). During the 5 years immediately after menopause, calcium supplementation has very little effect on bone loss (2569,2570,2575,2576). The rapid loss of estrogen causes a high bone resorption rate, which increases serum calcium levels and therefore decreases intestinal absorption of calcium (2570). After this period, the typical rate of bone loss is 2% per year (2572,2576). Taking calcium 1000-1600 mg daily as carbonate, citrate, lactate gluconate, or citrate malate salt decreases this rate by 0.25% to 1% annually (977,979,981,2569,2571,2572,2575,2576,2578,6850)(38978,38980,39064). The greatest reductions (1% or more) are seen in the first 1-2 years of supplementation when bone remodeling foci can be filled (2569,2576). After this period, the differences in rate of loss between supplemented and non-supplemented females are closer to 0.25% per year (2569,2577). A meta-analysis of clinical evidence suggests that there is no additional benefit after 4 years (38980). Small clinical studies have found that continuous calcium supplementation at an average daily dose of 1050 mg, started after menopause and continued for 1.5-4 years, may reduce fracture rates by 26% when compared with no calcium supplementation. The largest of these studies was conducted in nursing home residents who also received daily vitamin D; the benefits of calcium, specifically, are unclear (39386). Some research also suggests that calcium and vitamin D improves primary prevention of osteoporotic fractures in some older individuals with osteoporosis, particularly the elderly and those who are no longer community dwelling (12930,38875,38849,39026,109471). However, not all research is positive. One large clinical trial in elderly adults with a low-trauma fracture show that taking calcium 1000 mg daily with or without vitamin D 800 IU daily for 2-7 years does not reduce the risk of a second fracture when compared with placebo (13073). Another clinical study shows that taking calcium 1000 mg daily plus vitamin D 800 IU daily does not prevent a second fracture in elderly patients, or prevent a first fracture in elderly patients with other risk factors such as low body weight (less than 58 kg, 127.6 pounds), smoking, family history of hip fracture, or fair or poor self-reported health (12929). Also, some exploratory research suggests that supplements may need to be continued indefinitely; in adults over 68 years of age, any effects of 2 years of calcium supplements on BMD appear to be lost within 2 years after discontinuing supplements (6853). Calcium has additive effects when used with other agents such as vitamin D, estrogens, or calcitonin. Whereas calcium alone generally reduces or prevents loss of BMD, combination with other agents can produce small increases in BMD ranging from 0.3% to 3.3% depending on the combination and dosages used (978,980,1836,2570,2571,2572,2576). However, one meta-analysis in healthy adults shows that fortifying foods with calcium 250-1000 mg daily, in conjunction with vitamin D supplementation, for up to 24 months does not improve BMD when compared with control (107232). The full potential of osteoporosis treatments cannot be realized without adequate calcium intake (2569,2570,2571,2572). Advise patients taking agents such as estrogens, calcitonin, bisphosphonates, or raloxifene (Evista) to ensure that their daily calcium intake meets the RDA. Use supplements if necessary. The usefulness of calcium in preventing osteoporosis in males is not as well-studied. Some observational research has found that calcium 870 mg daily is not associated with changes in BMD and bone loss in males (97201). However, clinical evidence suggests that taking calcium 1000 mg daily for 2 years might improve trabecular or cortical bone mass by 2% to 4% (980,8827,8873). Dietary supplementation with calcium and vitamin D seems to moderately reduce bone loss measured in the femoral neck, spine, and total body, and seems to reduce the incidence of nonvertebral fractures in older patients with osteopenia or low BMD (980).
• Premenstrual syndrome (PMS). Adequate calcium intake seems to prevent symptoms of PMS. Details: There seems to be a link between low dietary calcium intake and symptoms of PMS (2004,6847,39007). Taking calcium 1000-1336 mg daily seems to significantly reduce depressed mood, water retention, and pain, especially if daily calcium intake is inadequate (1822,1823,1824,2004,95821). Calcium carbonate 1200 mg daily seems to decrease PMS symptom scores by about 18% when compared with placebo (1822). Increasing dietary calcium intake is also associated with a decreased risk of developing PMS. Consuming an average of 1283 mg of calcium per day from foods is associated with about a 30% lower risk of developing PMS compared with consuming an average of 529 mg daily (13094); however, taking calcium supplements does not appear to be associated with the risk of developing PMS.

POSSIBLY EFFECTIVE

• Colorectal cancer. Oral calcium seems to be beneficial for preventing colorectal cancer, especially in those with adequate vitamin D levels and normal body mass index (BMI). Details: Population studies have found that increased intake of dietary or supplemental calcium is associated with a reduced risk of colorectal cancer and colorectal adenomas (1047,8820,12120,38951,98898,98899). Clinical trials and meta-analyses of clinical research also show that taking calcium supplements 1.2-2 grams daily for up to 4 years can reduce the risk of colorectal adenoma recurrence by up to 29% (970,12118,12950,15267,34596,38718,39042,95817). However, not all research has been positive. Some meta-analyses of clinical research or observational studies suggest that taking calcium does not reduce the risk of familial adenomatous polyposis or colorectal cancer (34596,39042,39349). Other contradictory research suggests that postmenopausal females who take calcium 1000 mg daily plus vitamin D 400 IU daily do not have a reduced risk of developing colorectal cancer (14290); however, this finding may not be reliable due to the high baseline intake of calcium in study participants. The reason for these conflicting findings is not entirely clear. Vitamin D might be an important factor. People with lower than average vitamin D levels do not seem to get any benefit from calcium supplements (12118). Also, one meta-analysis of previous trials suggests that taking calcium 1200 mg daily reduces the risk of colorectal adenomas in people with a normal BMI, but not in those who are overweight or obese (99715). Despite this conflicting evidence, the US Food and Drug Administration (FDA) approved a qualified health claim in 2005 stating that calcium supplements may reduce the risk of colorectal cancer and colorectal adenomas. However, the FDA has determined that there is little scientific evidence to support this claim (102366).
• Fetal bone mineralization. If calcium intakes are low during pregnancy, oral calcium seems to be beneficial for increasing fetal bone density. Details: With low dietary calcium intake (less than 562 mg elemental calcium daily) during pregnancy, calcium supplementation increases fetal bone mineralization and density. However, calcium supplementation does not offer any additional benefit if calcium intakes are adequate (3263,3264).
• Hypertension. Oral calcium seems to reduce blood pressure by a small amount in adults with or without hypertension. However, it is unclear if this reduction is clinically significant. Details: Many clinical trials and observational studies, including a meta-analysis of 18 high-quality clinical trials, show that intake of calcium supplements or dietary calcium modestly reduces systolic blood pressure in patients with or without hypertension, usually around 1-2 mmHg. Calcium seems to be more effective for certain subpopulations of patients, such as those who are salt-sensitive or have low baseline dietary calcium intake (945,972,974,976,984,1818,1819,1820,1821,6852)(13138,14406,38803,39063,39094,39221,113920,113925). However, a large-scale clinical trial in postmenopausal females shows that taking vitamin D (cholecalciferol) 400 IU daily in combination with elemental calcium 1000 mg daily does not lower blood pressure or reduce the risk of developing hypertension (16714). Additionally, a meta-analysis of 8 clinical trials shows that taking calcium in combination with vitamin D for up to 7 years has no effect on blood pressure (98861). The validity of this finding is limited by the poor methodological quality of the included studies. Some observational research suggests that calcium can reduce the risk for hypertension. Population research in females aged 45 years and older suggests that higher intake of calcium from both diet and supplemental sources is linked to a lower risk of developing hypertension when compared to lower calcium intake (14265). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim stating that calcium supplements may reduce the risk of hypertension. However, the FDA has concluded that this claim is based on supporting, rather than conclusive, evidence (102367). Research evaluating the effect of calcium supplementation during pregnancy on the child's blood pressure has yielded conflicting findings. A systematic review of 2 clinical studies and 3 observational studies found that calcium intake during pregnancy is associated with a 1-2 mmHg reduction in the systolic blood pressure of the offspring between the ages of 1-7 years (38852). However, a separate meta-analysis of 3 clinical studies shows that calcium intake during pregnancy does not reduce systolic or diastolic blood pressure in the offspring (113923).
• Osteomalacia. Oral calcium seems to reverse osteomalacia caused by very low calcium intakes. Details: Osteomalacia is commonly caused by vitamin D deficiency; however, very low calcium intake can also lead to osteomalacia in children and adults. Calcium supplementation can reverse osteomalacia caused by calcium deficiency. Along with appropriate vitamin D supplementation, individuals at risk of osteomalacia need sufficient calcium intake (94819).
• Pre-eclampsia. Oral calcium seems to reduce the risk of pre-eclampsia, especially in high-risk individuals and those with low baseline dietary calcium intake. Details: Although there is some conflicting evidence (971,38756), most clinical research shows that taking calcium orally 1-2 grams daily reduces the risk of pre-eclampsia (973,1833,8828,39043,39319,39426,97348,113919). A large clinical trial of 11,000 pregnant individuals in India and Tanzania shows that supplementation with 500 mg daily is similarly effective to 1500 mg daily (113908). Multiple meta-analyses which include 16-30 clinical studies have found that varying doses of calcium supplementation reduce the relative risk of pre-eclampsia by 46% to 51% when compared with placebo (97348,113909,113919). One of these meta-analyses found that for every 19 females treated with calcium, one episode of pre-eclampsia would be avoided (97348). Additionally, one of these meta-analyses found that calcium reduces the relative risk of pre-eclampsia by 51%, regardless of whether it is taken at a dose above or below 1000 mg daily (113919). Some research suggests that calcium supplementation may have a greater effect in individuals at high risk of pre-eclampsia or with low baseline dietary calcium intake, and when taken at greater than or equal to 20 weeks of gestation (15029,38497,97348,99714,113919). However, another meta-analysis of 30 clinical studies found a similar benefit of calcium in both high- and low-risk individuals (113919). A separate meta-analysis of 6 clinical studies conducted in China evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy. This combination was associated with an 80% lower relative risk of pre-eclampsia and an 83% lower relative risk of pre-eclampsia with gestational hypertension when compared with routine care (113913). In 2005, the US Food and Drug Administration (FDA) approved a qualified health claim regarding the use of calcium supplements to reduce the risk of pregnancy-induced hypertension and pre-eclampsia. However, due to the limited and conflicting research available at that time, the FDA stated that this outcome was highly unlikely (102366). Since then, large, high-quality clinical research has supported this finding. In fact, in 2016 the World Health Organization (WHO) released a recommendation to prescribe oral calcium 1.5-2 grams daily during pregnancies at high risk of pre-eclampsia if dietary calcium intakes are low (97347).
• Pregnancy-induced hypertension. Oral calcium may reduce the risk of pregnancy-induced hypertension. Details: A meta-analysis of 17 clinical studies shows that calcium supplementation during pregnancy may reduce the relative risk of pregnancy-induced hypertension by 30% when compared with control (113909). A separate meta-analysis of 6 clinical studies conducted in China, which evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy, shows that this combination reduces the relative risk of pregnancy-induced hypertension by 85% when compared with routine care (113913).
• Rickets. Oral calcium seems to reverse rickets caused by very low calcium intakes. Details: Rickets is commonly caused be vitamin D deficiency; however, very low calcium intake can also lead to rickets. Calcium supplementation can reverse rickets caused by calcium deficiency (94819). A small clinical study in children with nutritional rickets shows that taking calcium 500-2000 mg daily for 24 weeks improves radiographically measured rickets caused by calcium deficiency. Rickets seems to improve more rapidly with calcium 1000 mg compared to calcium 500 mg. However, increasing the calcium dose to 2000 mg daily is not more beneficial than calcium 1000 mg daily (98904).
• Tooth retention. Oral calcium with vitamin D seems to help with tooth retention in the elderly population. Details: A clinical trial in the elderly population shows that taking calcium citrate malate 500 mg daily along with vitamin D3 (cholecalciferol) 700 IU daily orally for 3 years reduces the risk of tooth loss by about 52% when compared with placebo (8816).

POSSIBLY INEFFECTIVE

• Breast cancer. Oral calcium, via supplementation or as part of the diet, does not seem to be beneficial for breast cancer prevention. Details: Although some studies disagree (15631,39041,95811,107237,113917), most population research suggests that increased calcium intake is not associated with overall breast cancer risk (15631,16715,98895,107236,107237,113917). However, one meta-analysis of observational studies shows that although higher total calcium intake is not associated with breast cancer risk, higher dietary calcium intake, specifically, may be associated with a slightly reduced risk (113917). Also, some analyses suggest that calcium intake may be associated with the risk for certain breast cancer sub-types. Some subgroup analyses suggest that calcium intake may reduce the risk of breast cancer in postmenopausal, but not pre-menopausal, adults (15631,107237) and that dietary calcium intake may reduce estrogen receptor(ER)-negative breast cancer, but not ER-positive breast cancer (107236). However, most research has not evaluated the effects of calcium supplementation or intake on breast cancer subtypes. The best evidence to date, from a large scale clinical trial (Women's Health Initiative), shows that taking vitamin D (cholecalciferol) 400 IU daily plus calcium 1000 mg daily for 7 years after menopause does not reduce the risk of developing invasive breast cancer at the end of the study and 5 years after the end of the intervention (16715,98895).
• Fractures. Although oral calcium prevents fractures in osteoporosis, most evidence shows that calcium does NOT prevent factures in people who do not have osteoporosis. See Osteoporosis discussion for more information on the use of calcium for this purpose. Details: Robust meta-analyses of mostly large, high-quality clinical studies show that calcium supplementation 500-1600 mg daily for 0.5-7 years with or without vitamin D does not reduce total fractures, hip fractures, vertebral fractures, or non-vertebral fractures in older adults without osteoporosis (95822,112486). A large-scale study in postmenopausal females aged 50-79 years who were enrolled in the Women's Health Initiative (WHI) suggests that calcium 1000 mg plus vitamin D 400 IU daily for 7 years only modestly improves bone mineral density (BMD) and does not significantly reduce fracture risk. This lack of effect may have been due to low adherence to the treatment regimen. In those who were 80% adherent, the combination of calcium plus vitamin D reduced the risk of hip fracture by about 29% (14282). Also, some clinical research shows that taking calcium carbonate 1000 mg and vitamin D 400 IU for 5 years does not attenuate loss of height after menopause when compared with placebo (95810). Additional meta-analyses of clinical and observational evidence suggest that calcium supplementation is not associated with a reduced risk of vertebral or nonvertebral fractures, such as hip fractures (38589,38888,98895). Some other research has suggested that calcium in combination with vitamin D reduces fracture risk in older patients without osteoporosis (980,1836,8818,12930,12933,12952,38849,102145,107235); however, this research is confounded by a number of variables, including the presence of hormonal therapy and differing levels of fracture risk at baseline (1836,8818,95822). Conflicting findings on this topic might also be due to genetic differences in patient populations. A population analysis of the WHI study found that, in older females with the lowest genetic susceptibility to low BMD, taking calcium with vitamin D is associated with a reduction in fracture risk. However, in females with a higher genetic susceptibility to low BMD, there is no association between supplementation and fracture risk. This might be because individuals with a lower susceptibility to low BMD are also more responsive to calcium and vitamin D supplementation (97357). As of April 2018, the U.S. Preventative Services Task Force (USPSTF) concludes that there is insufficient evidence to determine whether supplementing with vitamin D >400 IU daily along with calcium >1000 mg daily is safe and effective for preventing fractures in community dwelling adults without vitamin D deficiency, osteoporosis, or a history of fracture. USPSTF recommends against supplementing with calcium 1000 mg daily or less along with vitamin D 400 IU daily or less for preventing primary fractures in community-dwelling postmenopausal females (95695).
• Obesity. Oral calcium does not seem to improve weight loss in adults or children with overweight or obesity. Details: Observational research has found that adults and children with low calcium intake are more likely to gain weight, have a higher body mass index (BMI), and be overweight or obese when compared to people with high calcium intake (12124,12125,12126,12127,14265). Additional observational research has found that increasing calcium intake is associated with weight loss in females; the results in males have been conflicting (12127,15602,15603). Despite these findings from observational research and a few small clinical studies (12128,15397,14438,98905,113918), most clinical research has found that increased calcium intake does not increase weight loss (12052,13138,15396,15399,38985,39004,97356). A meta-analysis of 20 clinical studies shows that daily dietary and supplemental calcium intake that meets the dietary reference intake (DRI) of 1000 mg or more daily does not increase weight loss in overweight individuals or patients with obesity when compared with intake below the DRI (95813). An older meta-analysis of 13 clinical trials also shows that increased dietary and supplemental calcium intake does not increase weight loss (15605).
• Overall mortality. Oral calcium does not seem to reduce overall mortality. Details: While some population research has found that calcium taken in combination with vitamin D in older females is associated with a lower risk of death (97353), most evidence shows that calcium, with or without vitamin D, has no effect on all-cause mortality (93533,97308,113584).

INEFFECTIVE

• Cardiovascular disease (CVD). Oral calcium does not reduce the risk of developing CVD and may actually increase risk in some patients. Details: Clinical research shows that calcium does not decrease CVD risk. Several separate meta-analyses of clinical and population research involving over 50,000 patients show that taking calcium 600-1200 mg daily for up to 7 years does not reduce the risk of CVD-related outcomes, including stroke and myocardial infarction, cardiovascular death, or overall mortality (39018,91350,92994,93533,97308,98902,107231,107233). No association was found between total dietary or supplemental calcium intake with or without vitamin D and the risk of CVD or mortality (91350,93533,97308). In fact, some population and clinical research has found that when calcium is used alone or with vitamin D, there is an INCREASED risk of CVD and coronary heart disease (38077,107233). However, other clinical research disagrees (93533). One meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years increases the risk of CVD and coronary heart disease by 1.1-1.2 times when compared with control. However, the majority of the included research evaluated postmenopausal females and it is unclear if this finding is applicable to other populations (107233).
• Chemotherapy-induced peripheral neuropathy. Intravenous calcium does not prevent nerve pain in patients given oxaliplatin. Oral calcium has not been evaluated for this purpose. Details: While pooled analyses of cohort studies and randomized controlled trials suggest that calcium and magnesium infusion decreases the incidence of oxaliplatin-induced neurotoxicity, a meta-analysis of only randomized controlled trials shows that the infusion has no effect in preventing neurotoxicity (90028,90029,90031). Additionally, clinical trials show that administering calcium gluconate 1 gram with magnesium sulfate 1 gram intravenously immediately before, or before and after, the administration of a single oxaliplatin cycle (90005), or over the entire 6-cycle course of oxaliplatin, does not improve symptoms of neurotoxicity when compared with placebo (96474).
• Myocardial infarction (MI). Oral calcium does not prevent MI. When taken in the absence of vitamin D, oral calcium may increase the risk of MI. Details: Population research has found that increased dietary intake of calcium is associated with a decreased risk of MI (91350). However, a 2010 meta-analysis of clinical research shows that taking calcium at a dose of at least 500 mg daily is associated with an approximate 30% INCREASE in the risk of MI in patients over the age of 40. According to this analysis, one additional case of MI will occur for every 69 patients that take calcium for 5 years (17482). A more recent meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years increases the risk of MI by 1.2 times when compared with control. However, the majority of the included research studied postmenopausal females and it is unclear if this finding is applicable to other populations (107233) In contrast, other meta-analyses of clinical research have shown that taking calcium for up to 7 years is NOT associated with an increased risk of MI, including a meta-analysis that only included postmenopausal females (93533,107231). Reasons for these discrepancies are not entirely clear. It may relate to whether calcium is taken as monotherapy or in combination with vitamin D. When taken with vitamin D, which is commonly recommended, calcium supplementation does not appear to be associated with an increased risk of MI in postmenopausal females (93533). Also, the association between calcium supplementation and MI risk may be influenced by the amount of calcium consumed as part of the diet. Supplementation with calcium may be associated with an increased risk of MI in people with dietary calcium intake above 805 mg daily, but not in those with dietary calcium intake below 805 mg daily (17482)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alcohol use disorder. It is unclear if oral calcium is beneficial for alcohol use disorder. Details: Preliminary clinical research shows that taking calcium carbonate 800 mg and vitamin D 200 IU orally daily for 14 days modestly reduces alcohol craving scores and withdrawal scores when compared with placebo in adults with alcohol dependence that are undergoing withdrawal. Taking calcium carbonate did not reduce the need for diazepam; however, the study may have been inadequately powered to detect a difference between groups (107234).
• Atherosclerosis. It is unclear if oral calcium is beneficial for atherosclerosis. Details: A population study has found that taking calcium 1.2 grams daily for 3 years has no effect on carotid intima thickness or carotid atherosclerosis incidence. A total calcium intake (dietary and supplemental) of at least 1794 mg daily in older females may be associated with a decreased risk of carotid atherosclerosis when compared with a total calcium intake below 1010 mg daily (97351).
• Autism spectrum disorder. It is unclear if oral calcium during pregnancy is beneficial for reducing the odds of autism spectrum disorder in the offspring. Details: A small observational study found that calcium supplementation during pregnancy is associated with a 52% reduced odds of an autism spectrum disorder in the offspring (98900).
• Brain tumor. It is unclear if dietary calcium intake is associated with risk of brain tumor. Details: A meta-analysis of 4 case-control studies has found that higher dietary calcium intake is associated with a lower odds of brain tumor when compared with lower dietary intake (113922). The validity of this finding is limited by the exploratory nature of the included studies, which analyzed all dietary ingredients for any potential associations.
• Cancer. Oral calcium alone does not seem to prevent cancer. It is unclear if oral calcium with vitamin D is beneficial for preventing cancer. Details: Taking calcium alone does not seem to significantly reduce the risk of cancer (12118,15629). The role of calcium in cancer prevention when taken along with vitamin D is controversial, as conflicting results exist. One clinical trial shows that healthy postmenopausal females who take supplemental calcium 1400-1500 mg daily plus vitamin D3 (cholecalciferol) 1100 IU daily have a 60% lower relative risk for developing cancer of any type. Approximately 25 postmenopausal females would need to take this combination for 4 years to prevent one occurrence of cancer (15629). However, a more recent clinical study shows that healthy postmenopausal females who take supplemental calcium 1500 mg daily plus vitamin D3 (cholecalciferol) 2000 IU daily do not have a reduced risk of cancer at 4 years (93943). Reasons for the disparate results are not entirely clear. The discrepancies do not appear to be related to baseline vitamin D levels or different study populations. It is possible that, given the 10-year time lapse between the two publications, the discrepancies result from differences in cancer detection capability. Also, since cancer risk was a secondary outcome measure in the earlier study and a primary outcome measure in the more recent study, it is possible that the discrepancies result from differences in statistical methodologies. The effect of vitamin D and calcium on cancer risk in males and younger patients is not known. There is also interest in using calcium for reducing the risk of hematological malignancies. An analysis of the Women's Health Initiative study shows that taking calcium 1000 mg daily in combination with vitamin D3 400 IU for up to 10 years is associated with a 20% reduction in the risk of hematologic malignancies when compared with placebo. However, no effect on hematologic malignancy related mortality was seen (97354).
• Depression. It is unclear if oral calcium is beneficial for depression prevention. Details: Population research has found no association between a higher dietary intake of calcium and the risk of depression when compared with a lower dietary intake of calcium (96480).
• Diabetes. It is unclear if dietary calcium intake is associated with type 2 diabetes risk. Details: Some population research has found that a higher intake of calcium from the diet or supplements, alone or in combination with vitamin D, is associated with a lower risk of developing type 2 diabetes when compared with lower calcium intake (14265,16713,96473,113929). One meta-analysis of cohort and cross-sectional studies found that the highest level of dietary calcium intake is associated with an 18% relative reduction in risk of type 2 diabetes when compared with the lowest level of intake. A dose-response analysis suggests that each 300, 600, and 1000 mg per day increase in dietary calcium intake is associated with a 7%, 14%, and 23% reduced risk of type 2 diabetes, respectively (113929). However, population research is often limited by confounding variables. For example, one analysis suggests that any beneficial effect might be influenced by concomitant magnesium intake (96473,113929), while another suggests that any benefit from increased intake may be more pronounced in females, adults aged 50 years or older, and Asian populations (113929). Furthermore, other population research has found that serum calcium levels higher than 9.6 mg/dL are associated with greater risk of developing diabetes in Chinese adults with osteoporosis (95815).
• Dyslipidemia. It is unclear if oral calcium is beneficial for dyslipidemia. Details: One clinical study in adults with mild to moderate hypercholesterolemia shows that adding calcium carbonate 400 mg three times daily to a low-fat diet (American Heart Association Step 1) for 6 weeks reduces low-density lipoprotein (LDL) cholesterol levels by 4% and increases high-density lipoprotein (HDL) cholesterol levels by 4% when compared with the low-fat diet and placebo (2557). In contrast, a clinical study in females with dyslipidemia shows that taking calcium 800 mg daily for 2 years INCREASES total cholesterol levels and carotid intima-media thickness in postmenopausal, but not premenopausal, females when compared with placebo (97350). Calcium supplementation has also been evaluated in combination with vitamin D. A meta-analysis of randomized controlled trials including adults with normolipidemia and dyslipidemia shows that taking calcium 500-2000 mg daily and vitamin D 200-7142 IU daily modestly improves HDL cholesterol and triglyceride levels, but not LDL cholesterol levels, when compared with placebo. Subgroup analyses suggest that calcium and vitamin D supplementation is most beneficial in patients with dyslipidemia at baseline (107227). The relationship between dietary calcium intake and serum lipid levels has also been evaluated in observational research. A meta-analysis of 7-11 observational studies found that dietary calcium intake is not associated with total cholesterol levels, although small differences in individual lipid parameters were identified. Additionally, a meta-analysis of 4-9 observational studies suggests that calcium intake is not associated with the risk of developing hypertriglyceridemia, hypercholesterolemia, or low HDL. A subgroup analysis found that higher calcium intake may be associated with lower triglyceride levels in Asian populations (113927). Overall, these findings are limited by significant heterogeneity and the cross-sectional nature of the included studies.
• Dysmenorrhea. It is unclear if oral calcium is beneficial for reducing pain associated with dysmenorrhea. Details: Clinical research shows that taking calcium carbonate 1000 mg with vitamin D 5000 IU daily for three menstrual cycles does not reduce pain when compared with placebo in patients with primary dysmenorrhea (95821). However, calcium carbonate 1000 mg taken alone seems to reduce pain when compared with placebo.
• Endometrial cancer. It is unclear if oral calcium is beneficial for endometrial cancer prevention. Details: A meta-analysis of population research suggests that calcium supplements may reduce the risk of endometrial cancer, but dietary calcium does not seem to have any effect (38893).
• Exercise-induced muscle damage. It is unclear if oral calcium is beneficial for reducing exercise-induced muscle damage. Details: A very small clinical study in resistance-trained adults shows that taking calcium carbonate 500 mg 4 times daily for 3 weeks does not attenuate exercise-induced muscle damage from bench presses when compared with placebo (113933). This study may have been inadequately powered to detect a difference between groups.
• Fall prevention. It is unclear if oral calcium with vitamin D is beneficial for preventing falls. Details: Research suggests that calcium in combination with vitamin D, but not calcium alone, might prevent falls by decreasing body sway and normalizing systolic blood pressure (6362,11939,39038). Some experts think the combination of calcium and vitamin D may be important (11916). Preliminary clinical research in adults residing in a health care facility shows that taking vitamin D supplements while increasing dietary calcium and protein for 2 years reduces falls by 11% when compared with standard diets. Intervention diets were supplemented with milk, yogurt, and cheese to provide calcium 1142 mg and protein 69 grams daily (107235). There might also be different effects in females compared to males. In one study, females aged 65 years or older who took vitamin D 700 IU plus calcium citrate 500 mg daily over a 3-year period had a 46% lower risk of falling. However, this combination did not decrease falls in males (14291).
• Fluorosis. Oral calcium has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Taking calcium orally, in combination with ascorbic acid (vitamin C) and vitamin D, seems to be effective for reducing excessive fluoride levels in children and improving symptoms of fluorosis in children aged 6-12 years (990).
• Heart failure. It is unclear if oral calcium in combination with vitamin D is beneficial for preventing heart failure. Details: Based on a secondary analysis of a large-scale clinical trial (Women's Health Initiative), taking calcium 1000 mg with vitamin D 400 IU daily does not reduce the risk of heart failure in the overall population or in individuals at high risk. However, in a subgroup of postmenopausal females without risk factors for heart failure, calcium and vitamin D supplementation might reduce the risk of developing heart failure by about 37% (97307).
• Lead toxicity. It is unclear if oral calcium is beneficial for reducing blood levels of lead. Details: Lead is mobilized along with calcium from bone during pregnancy and lactation, resulting in increased serum concentrations of lead. One clinical study suggests that calcium supplementation does not significantly decrease these elevated lead concentrations (1586). However, another clinical study suggests that taking calcium reduces blood lead levels by 11% when compared with placebo, with greatest effects observed in those with high baseline levels of lead (38957).
• Lyme disease. Although there is interest in using oral calcium for Lyme disease, there is insufficient reliable information about the clinical effects of calcium for this condition.
• Metabolic syndrome. It is unclear if oral calcium alone or with vitamin D is beneficial for metabolic syndrome prevention. Details: Population research has found that a higher intake of calcium from diet and supplements alone, or in combination with vitamin D, is associated with a lower risk of developing metabolic syndrome when compared with lower calcium intake (14265,16713).
• Nephrotic syndrome. It is unclear if oral calcium with vitamin D is beneficial for preventing nephrotic syndrome. Details: Clinical research shows that taking calcium 500-1000 mg daily for 3 months in combination with vitamin D3 60,000 IU daily or weekly for 4 weeks has no effect on bone mineral density or the risk of relapse in children with steroid-sensitive nephrotic syndrome (97355).
• Nonmelanoma skin cancer. It is unclear if oral calcium is beneficial for preventing keratinocyte carcinomas. Details: In middle aged and older adults recently diagnosed with a colorectal adenoma, clinical research shows that taking calcium 1200 mg daily as calcium carbonate for 3-5 years does not reduce the incidence of keratinocyte cancer when compared with placebo over a median of 8 years. A sub-group analysis shows that taking calcium alone or with vitamin D3 1000 IU daily reduced the risk of invasive cutaneous squamous cell carcinoma by a moderate amount, but had no effect on the risk of basal cell carcinoma (104622).
• Oral mucositis. When used in combination with fluoride treatments, a calcium phosphate mouth rinse seems to prevent and reduce mucositis-related pain in patients undergoing hematopoietic stem cell transplantation (HSCT). Details: A small clinical study in patients undergoing HSCT shows that using a particular mouth rinse (Caphosol, EUSA Pharma) containing calcium phosphate, in combination with fluoride treatments, reduces days of mucositis, the duration of pain, and the dose and days of morphine used when compared with placebo and fluoride treatment (38611).
• Ovarian cancer. It is unclear if oral calcium is beneficial for ovarian cancer prevention. Details: An older meta-analysis of 12 cohort studies found that dietary calcium intake is not associated with a reduced risk of ovarian cancer (38792). However, a more recent pooled analysis of 15 cohort and case-control studies has found that the highest intake of dietary or dairy calcium is associated with a 20% lower risk of ovarian cancer when compared to the lowest intake (97349).
• Postpartum depression. It is unclear if oral calcium is beneficial for reducing postpartum depression risk. Details: Preliminary clinical research shows that taking calcium 2 grams daily beginning at 11-21 weeks gestation reduces depression at 12 weeks postpartum when compared with placebo. However, no benefit is seen at 6 weeks postpartum (39447).
• Pregnancy-related leg cramps. It is unclear if oral calcium is beneficial for preventing leg cramps during pregnancy. Details: A small clinical study shows that taking calcium 1 gram twice daily (as a mixture of salts) for 2 weeks can reduce pregnancy-related leg cramps during the second half of pregnancy when compared with no treatment (2567).
• Prematurity. It is unclear if supplemental calcium is beneficial for the growth and development of preterm infants. Details: A small clinical study in preterm infants consuming human milk shows that supplementation with calcium 45 mg/kg daily and phosphorus 25 mg/kg daily does not affect infant weight, length, head circumference, or risk of osteopenia after 6 weeks when compared with human milk alone (113924). However, the duration and size of this study may have been too limited to detect any difference between groups.
• Preterm labor. It is unclear if oral calcium reduces the risk of preterm labor. Details: A meta-analysis of 10 clinical studies shows that taking calcium supplements during pregnancy does not reduce the risk of preterm labor when compared with placebo (113909). A separate meta-analysis of 7 clinical studies conducted in China, which evaluated the benefits of calcium carbonate 500-600 mg daily taken in conjunction with aspirin 50-75 mg daily during pregnancy, shows that this combination reduces the relative risk of preterm labor by 74% when compared with routine care (113913).
• Prostate cancer. It is unclear if oral calcium is beneficial for prostate cancer prevention. Details: Some clinical research shows that taking calcium 1200 mg daily might decrease the risk of developing prostate cancer (14133). However, some epidemiological research suggests that consuming very high doses of calcium, over 2000 mg daily, might actually increase the risk of developing prostate cancer (14134). Some epidemiological research also suggests that doses greater than 1500 mg daily increase the risk of poorly differentiated, clinically advanced, and fatal prostate cancer (14132). Consumption of dairy products has also been weakly linked to a modest increase in risk of prostate cancer (98894). However, contradictory research suggests that there is no association between dietary intake of calcium and overall risk of prostate cancer (14131,14132,104630).
• Stroke. It is unclear if oral calcium is beneficial for stroke prevention. Details: Some population research has found that increasing dietary calcium intake is associated with a decreased risk of ischemic stroke (4822,38678). However, other population research has found that increasing dietary calcium intake is not associated with a decreased risk of stroke (91350). One meta-analysis of high-quality randomized controlled trials shows that taking calcium for 2-7 years does not affect the risk of stroke when compared with control. However, the majority of the included research evaluated postmenopausal females, and it is unclear if this finding is applicable to other populations (107233).
• Vertigo. Oral calcium with vitamin D might reduce positional vertigo; the effect of calcium when used alone is unclear. Details: A large clinical study in adults with recurrent benign paroxysmal positional vertigo shows that taking calcium 500 mg and vitamin D 400 IU twice daily for one year reduces annual recurrence of vertigo by 27% when compared with no treatment. The number needed to treat to prevent vertigo was 3.7 (103681). It is unclear if this benefit is due to vitamin D, calcium, or the combination. More evidence is needed to rate calcium for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Asthma. Although there has been interest in using oral damiana for asthma, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Cognitive function. Although there has been interest in using oral damiana for cognitive function, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Constipation. Although there has been interest in using oral damiana for constipation, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Depression. Although there has been interest in using oral damiana for depression, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Diabetes. Although there has been interest in using oral damiana for diabetes, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Dyspepsia. Although there has been interest in using oral damiana for dyspepsia, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Erectile dysfunction (ED). Oral damiana has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized, open-label clinical study in adults with mild-to-moderate ED shows that taking a specific combination supplement (Icarifil, Anvest Health S.p.A) containing damiana 100 mg, panax ginseng, L-carnitine, L-citrulline, tribulus, and other ingredients daily for 3 months improves patient-reported erectile function when compared to baseline. Additionally, taking the supplement with tadalafil improves some, but not all, patient-reported assessments of erectile function when compared with taking tadalafil alone (114989). It is unclear if this effect is due to damiana, other ingredients, or the combination. Additionally, the interpretation of these results is limited by poor methodology, including the use of per-protocol analysis and lack of a placebo group.
• Headache. Although there has been interest in using oral damiana for headache, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Menopausal symptoms. Although there has been interest in using oral damiana for menopausal symptoms, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Obesity. Oral damiana has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in overweight adults shows that taking a combination product containing damiana 36 mg, guarana 95 mg, and yerba mate 112 mg, orally three times daily for 45 days increases weight loss when compared with placebo (11866). It is unclear if this effect is due to damiana, other ingredients, or the combination.
• Nocturnal enuresis. Although there has been interest in using oral damiana for nocturnal enuresis, there is insufficient reliable information about the clinical effects of damiana for this purpose.
• Sexual dysfunction. Oral damiana has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a specific combination product containing damiana, L-arginine, Panax ginseng, ginkgo, vitamins, and minerals (ArginMax for Women, Daily Wellness Co.) improves sexual satisfaction and desire, increases orgasm frequency, and reduces vaginal dryness when compared with placebo in females interested in improving their sexual function (46933). It is unclear if this effect is due to damiana, other ingredients, or the combination. More evidence is needed to rate damiana for these uses.

(Read more about DAMIANA)

POSSIBLY EFFECTIVE

• Genital herpes. Oral eleuthero root extract might help to prevent and reduce the severity of genital herpes outbreaks. Details: One clinical study in patients with recurrent genital herpes infections shows that taking a specific eleuthero root extract (Elagen) 400 mg, standardized to contain eleutheroside 0.3%, daily for at least 3 months reduces the frequency, severity, and duration of outbreaks when compared with placebo (730).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Athletic performance. Small clinical studies suggest that oral eleuthero root is not beneficial for improving athletic performance. Details: One study in trained distance runners shows that a specific eleuthero root liquid extract, standardized to eleutherosides B and E content, taken as 3.4 mL daily for 6 weeks, does not affect endurance, performance, or psychological, cardiac, or respiratory parameters when compared with placebo (7522). Small studies in trained athletes or healthy adults show that taking eleuthero 800-1200 mg daily (Endurox) for 1-6 weeks does not seem to have any effect on cycling performance time, respiration, lactate production, or heart rate recovery during cycling, stair-stepping exercise, treadmill, or cycle ergometry when compared with placebo (2335,7600,7601,8994). However, there has been some speculation that a longer duration of supplementation is needed for benefit. One study in recreationally trained athletes shows that taking a specific powdered eleuthero root product 400 mg twice daily for 8 weeks increased cycling endurance time by 23% and maximal oxygen consumption by 12% when compared with placebo. This product was standardized to contain eleutheroside B 0.11% and eleutheroside E 0.12% (17186).
• Bipolar disorder. It is unclear if oral eleuthero root is beneficial for bipolar disorder. Details: A small clinical study in Chinese adolescents aged 12-17 years with bipolar disorder shows that taking eleuthero root 750 mg orally three times daily, in conjunction with lithium for 6 weeks, induces similar response rates and remission rates when compared with lithium plus fluoxetine 20 mg (75028). It is not clear how this response rate compares to the use of lithium alone.
• Cardiovascular disease (CVD). It is unclear if oral eleuthero fruit is beneficial for preventing the development of CVD. Details: One small clinical study in healthy adults with at least two cardiovascular risk factors shows that taking an aqueous extract of eleuthero fruit 500 mg daily for 12 weeks seems to modestly reduce systolic blood pressure and arterial stiffness, as measured by brachial-ankle pulse wave velocity, when compared with placebo. It did not affect diastolic blood pressure, flow-mediated dilation, or carotid intima-media thickness. Also, taking a higher 1000 mg dose of the same eleuthero extract daily did not have significant effects on any measured parameters (105025).
• Chronic fatigue syndrome (CFS). It is unclear if oral eleuthero root is beneficial for CFS. Details: One clinical study in adults with CFS shows that taking eleuthero root extract 2 grams daily for 2 months improves fatigue severity and duration when compared to baseline, but not when compared with placebo (11099).
• Cognitive function. It is unclear if oral eleuthero is beneficial for cognitive function. Details: A very small clinical study in middle-aged people shows that taking eleuthero 325 mg twice daily might improve selective memory when compared with placebo (2574). Another very small study in healthy adults shows that taking a combination product containing extracts of eleuthero leaf 203 mg and Drynaria fortunei 20 mg daily for 12 weeks improves figure recall, but not immediate memory or attention, when compared with placebo (102316). It is unclear if this effect is due to eleuthero, Drynaria fortunei, or the combination.
• Common cold. Oral eleuthero has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some clinical research shows that taking capsules of a specific combination product containing eleuthero plus andrographis (Kan Jang, Swedish Herbal Institute) orally improves symptoms of the common cold when started within 72 hours of symptom onset. Some symptoms can improve after 2 days of treatment; however, it typically takes 4-5 days of treatment for maximal symptom relief (5784,10795,12380). Some research shows the combination of eleuthero and andrographis relieves cold symptoms better than echinacea or placebo in children (12381). It is unclear if this effect is due to eleuthero, andrographis, or the combination.
• Coronavirus disease 2019 (COVID-19). Oral eleuthero extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with a history of COVID-19 infection and current symptoms of long COVID-19 shows that taking a specific combination product containing eleuthero extract 78 mg, rhodiola extract 90 mg, and schisandra extract 300 mg (ADAPT-232/Chisan, Swedish Herbal Institute) twice daily for 2 weeks increases exercise capacity by about 13 minutes but does not reduce the duration of cough, fatigue, headache, pain, or other respiratory problems when compared with placebo (109635). It is unclear if these findings are due to eleuthero, other ingredients, or the combination.
• Diabetes. It is unclear if oral eleuthero is beneficial for improving glycemic control in type 2 diabetes. Details: One small clinical study in adults with type 2 diabetes shows that taking a specific eleuthero extract, standardized to contain eleutherosides E and B 1.12%, as 480 mg daily for 3 months, decreases fasting glucose by a mean of 36 mg/dL, postprandial blood glucose by a mean of 35 mg/dL, glycated hemoglobin (HbA1c) by a mean of 0.8%, triglycerides by a mean of 106 mg/dL, and total cholesterol by a mean of 21 mg/dL when compared with placebo (91509).
• Diabetic neuropathy. It is unclear if oral eleuthero is beneficial for diabetic neuropathy. Details: One small clinical study in adults with type 2 diabetes shows that taking a specific eleuthero extract, standardized to contain eleutherosides E and B 1.12%, as 480 mg daily for 3 months, modestly improves subjective symptoms of diabetic neuropathy when compared with placebo (91509).
• Dry eye. Oral eleuthero root has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in adults with dry eye disease shows that taking a specific combination product containing eleuthero root 50 mg, zinc 10 mg, L-carnitine 50 mg, elderberry fruit extract 300 mg, and currant 100 mg (Meramirt CM) once daily improves dry eye symptom scores when compared with no intervention. Contrast sensitivity scores also improved when compared to baseline in the treated group, but not in the control group (111295). It is unclear if these effects are due to eleuthero, other ingredients, or the combination.
• Familial Mediterranean fever. Oral eleuthero has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in children ages 3-15 years with familial Mediterranean fever shows that taking a specific combination product (ImmunoGuard, Inspired Nutritionals) containing eleuthero, andrographis, schisandra, and licorice for one month reduces the duration, frequency, and severity of disease recurrence when compared with placebo (12382). It is unclear if this effect is due to eleuthero, other ingredients, or the combination.
• Fibromyalgia. Although there is interest in using oral eleuthero for fibromyalgia, there is insufficient reliable information about the clinical effects of eleuthero for this condition.
• Hangover. It is unclear if oral eleuthero root is beneficial for hangovers. Details: One small clinical study in healthy males shows that consuming one bottle of a powdered polysaccharide-rich extract of eleuthero root before and after consuming alcohol modestly reduces the severity of hangover as measured by the Acute Hangover Scale questionnaire score when compared with placebo (91508). However, the validity of these findings is brought into question due to the incomplete study information provided.
• Influenza. Oral eleuthero has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with influenza shows that taking a specific combination product containing eleuthero 20-30 mg plus andrographis 178-266 mg (Kan Jang, Swedish Herbal Institute) three times daily for 3-5 days relieves symptoms more quickly than amantadine. This combination product also reduced the risk of post-influenza complications, such as sinusitis or bronchitis, when compared with amantadine (10441). It is unclear if these effects are due to eleuthero, andrographis, or the combination.
• Osteoarthritis. Oral eleuthero has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking two capsules each containing 400 mg of a combination of eleuthero, Panax pseudoginseng, and rehmannia daily for 6 weeks improves physical function in individuals with knee osteoarthritis when compared with placebo. However, the combination does not seem to reduce pain or stiffness when compared with placebo (74950). It is unclear if this effect is due to eleuthero, other ingredients, or the combination.
• Osteoporosis. Oral eleuthero has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in postmenopausal patients shows that taking low-dose calcium and vitamin D3 in combination with a 250 mg blend of rehmannia root and eleuthero stem bark extracts twice daily for 12 months attenuates the loss of spine and femur bone mineral density when compared with placebo or high-dose calcium and vitamin D (75036). It is unclear if this effect is due to eleuthero, rehmannia, or the combination.
• Pneumonia. Oral eleuthero has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with acute, nonspecific pneumonia shows that taking a specific combination product (ADAPT-232), containing eleuthero, rhodiola, and schisandra, as 20 mL twice daily for 10-15 days in conjunction with conventional treatment, reduces the duration of antibiotic treatment and improves quality of life when compared with conventional treatment alone (71152).
• Quality of life. It is unclear if oral eleuthero root improves quality of life in older healthy adults. Details: A small clinical study in elderly volunteers shows that taking eleuthero 300 mg daily improves social functioning and mental well-being after 4 weeks of treatment when compared with placebo. However, this improvement was not maintained after 8 weeks of treatment (15586).
• Rheumatoid arthritis (RA). Although there is interest in using oral eleuthero for RA, there is insufficient reliable information about the clinical effects of eleuthero for this condition.
• Stress. It is unclear if oral eleuthero root is beneficial for stress. Details: One clinical study in adults 30-50 years of age with symptoms of stress shows that taking a specific eleuthero root extract (WS 1070) 120 mg daily for 8 weeks does not improve fatigue, exhaustion, cognitive alertness, or measures of stress when taken alone or in conjunction with stress management training (91510). However, another small clinical study in healthy females 20-68 years of age who have experienced stress for a prolonged period of time shows that taking 270 mg of a combination agent (ADAPT-232) containing eleuthero, rhodiola, and schisandra improves attention and cognitive speed and accuracy when compared with placebo (19289). It is unclear if these effects are due to eleuthero, other ingredients, or the combination.
• Upper respiratory tract infection (URTI). Oral eleuthero has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in adults with an uncomplicated URTI shows that taking 30 mL of a combination product (Kan Jang, Swedish Herbal Institute) containing extracts of eleuthero root (eleutherosides B and E 0.03 mg/mL), echinacea root, and malabar nut leaf daily does not reduce the severity or frequency of cough by a clinically meaningful amount after 3-4 days of treatment when compared with bromhexine hydrochloride or placebo (95648). However, a non-blinded clinical study shows that taking 30 mL of this same product three times daily for 6 days improves the severity and frequency of coughing and the degree of nasal congestion when compared with bromhexine. Additionally, patients taking the combination product recovered two days sooner, on average, than those taking bromhexine (48569). The reason for these conflicting findings is unclear but may be due to an inadequate duration of treatment in the first study and/or lack of blinding in the second study. Also, it is unclear if any benefit is due to eleuthero, other ingredients, or the combination. Other research has evaluated a capsule formulation of Kan Jang (Swedish Herbal Institute), with each capsule containing eleuthero root 11.4 mg and andrographis 195 mg. One small clinical study in patients with an uncomplicated URTI shows that taking this product as two capsules three times daily for 5 days reduces the median number of sick leave days to 2 days, compared with 3 days in the placebo group. It also increases the total number of recovered patients on day 3 to 75%, compared with 55% of those taking placebo (107471). More evidence is needed to rate eleuthero for these uses.

(Read more about ELEUTHERO)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Bronchitis. Although there is interest in using oral horny goat weed for bronchitis, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Coronary heart disease (CHD). Although there is interest in using oral horny goat weed for CHD, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Erectile dysfunction (ED). Although there is interest in using oral horny goat weed for ED, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Fatigue. Although there is interest in using oral horny goat weed for fatigue, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Gulf war syndrome. It is unclear if oral horny goat weed is beneficial in patients with Gulf war syndrome. Details: A small clinical study in males with Gulf war syndrome shows that taking horny goat weed extract 250 mg or 500 mg twice daily, standardized to contain 50 mg or 100 mg of icariin per dose, respectively, for 30 days does not improve symptoms of Gulf war syndrome when compared with placebo (108311).
• Hepatitis. Although there is interest in using oral horny goat weed for hepatitis, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• HIV/AIDS. Although there is interest in using oral horny goat weed for HIV/AIDS, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Hypertension. Although there is interest in using oral horny goat weed for hypertension, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Male infertility. Although there is interest in using oral horny goat weed for male infertility, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Memory. Although there is interest in using oral horny goat weed for memory, there is insufficient reliable information about the clinical effects of horny goat weed for this purpose.
• Myocarditis. Although there is interest in using oral horny goat weed for myocarditis, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Osteoarthritis. Although there is interest in using oral horny goat weed for osteoarthritis, there is insufficient reliable information about the clinical effects of horny goat weed for this condition.
• Osteoporosis. Several small, low-quality clinical studies suggest that horny goat weed may modestly improve bone mineral density (BMD) in patients with osteoporosis. Details: A meta-analysis of 12 small, low-quality clinical studies in patients with osteoporosis shows that taking horny goat weed alone or in combination with conventional therapy improves BMD when compared with a control group. When added to conventional therapy, horny goat weed appears to have a large effect on BMD, while its effect is more modest when used alone. The most common formulations and doses used include granules 1 gram twice daily for 6 months, an extract 600 mg taken in divided doses daily for 6 months, and a decoction 50 mL taken 2-3 times daily for 3-6 months. The pooled analysis suggests that horny goat weed decoctions are more effective than other formulations (109578). Additionally, a small clinical study in postmenopausal patients not included in the analysis above shows that taking a specific extract of horny goat weed containing 60 mg icariin, 15 mg daidzein, and 3 mg genistein (Xianling Gubao; Tong Ji Tang Pharmacal Company) daily, in addition to calcium 300 mg daily, for 24 months attenuates loss of BMD of the lumbar spine and femoral neck when compared with placebo plus calcium. BMD increased by 1.6% and 1.3% at each site, respectively, compared with decreases of 1.8% and 2.4%, respectively, with placebo (14900).
• Postmenopausal conditions. It is unclear if oral horny goat weed is beneficial in patients with postmenopausal conditions. Details: Preliminary clinical research in postmenopausal patients shows that taking horny goat weed water extract 300 mL daily for 6 months slightly decreases triglyceride and total cholesterol levels and can increase estradiol levels when compared with placebo (55452). The clinical significance of these effects is unclear.
• Sexual dysfunction. Although there is interest in using oral horny goat weed for sexual dysfunction, there is insufficient reliable information about the clinical effects of horny goat weed for this condition. More evidence is needed to rate horny goat weed for these uses.

(Read more about HORNY GOAT WEED)

POSSIBLY EFFECTIVE

• Angina. Oral L-arginine seems to improve symptoms and exercise tolerance in patients with angina. Details: Clinical research shows that taking L-arginine orally seems to decrease symptoms and improve exercise tolerance and quality of life in patients with mild to severe angina (3593,7815,7816,31866,31923). Some patients with severe angina who have frequent attacks at rest despite treatment with standard antianginal agents might also benefit from L-arginine (3593). However, L-arginine does not seem to improve objective measures of blood vessel dilation or increase circulating concentrations of nitric oxide (7817,99262). Also, when used in combination with ten 200 mcg injections of vascular endothelial growth factor (VEGF)-165 plasmid DNA, L-arginine 6 grams daily orally for 3 months does not improve angina severity in patients with coronary artery disease who underwent surgical angiogenesis compared to patients who did not receive this combination (32001). In addition, intravenous infusion of arginine 10% solution does not improve exercise capacity in patients with stable angina when compared with placebo (31843,32293).
• Erectile dysfunction (ED). Oral L-arginine might improve symptoms of ED. When taken with phosphodiesterase type 5 (PDE5) inhibitors, L-arginine seems to provide a small additional benefit. Details: Taking L-arginine orally in high doses, 5 grams daily, improves subjective assessment of sexual function in males with organic ED when compared with placebo (222,102586). Additionally, a meta-analysis of 4 small clinical studies in patients with ED, including those with diabetes and/or cardiovascular disease risk factors, shows that although PDE5 inhibitors improve sexual function better than L-arginine, the combination of PDE5 inhibitors and L-arginine may be more effective than either treatment alone (105065). In most clinical trials, doses of L-arginine 2.5-5 mg daily for 6-12 weeks were used alone or in addition to PDE5 inhibitors such as sildenafil 50 mg or tadalafil 5-10 mg daily (102586,102587,102592,104222). Higher doses have also been investigated. One clinical trial shows that taking L-arginine (Bioarginina, Farmaceutici Damor S.p.A., Napoli, Italy), 2 grams three times daily for 3 months improves sexual function compared with placebo (110387). However, taking lower doses, 1.5 grams daily, might not be effective in patients with mixed-type ED (2038). L-arginine has also been examined in combination with other ingredients. A meta-analysis of 2 small clinical studies in males with mild-to-moderate ED shows that taking L- arginine, up to 3 grams daily, in combination with maritime pine for 1-6 months improves a subjective assessment of sexual function when compared with control (112715). Some preliminary clinical evidence suggests that taking L-arginine orally in low doses, 1.7 grams daily in combination with maritime pine bark extract (Pycnogenol) or taking 0.69 grams daily along with maritime pine bark extract and aspartic acid (Edicare, Kobayashi Pharmaceutical Co. Ltd.) modestly improves symptoms of ED (10416,50924). Another preliminary clinical trial has investigated the effects of a combination of L-arginine 2.5 grams daily for 6 months and tadalafil 5 mg daily for 3 months, both starting with the initiation of weekly extracorporeal shock wave (ESW) therapy. When compared with ESW alone, this combination modestly improves sexual function for up to 12 months (110388). The effect of L-arginine alone is not clear from these studies.
• Hypertension. Oral L-arginine can modestly reduce systolic and diastolic blood pressure. Details: Oral L-arginine seems to have additive vasodilating effects when used with angiotensin converting enzyme (ACE) inhibitors or nitrate vasodilators such as isosorbide mononitrate (7822,20192,31916). A meta-analysis of clinical research in a variety of populations shows that taking L-arginine reduces systolic and diastolic blood pressure (SBP; DPB) by an average of 6.40 mmHg and 2.64 mmHg, respectively. Sub-analyses show that these reductions occur in both normotensive and hypertensive individuals. Beneficial effects were limited to adults with a body mass index (BMI) of 18.5 to 19.9 kg/m² (110384). The effect of L-arginine on blood pressure levels in adults exposed to traffic-related air pollution (TRAP) has also been investigated. Clinical research in adults with hypertension shows that taking L-arginine 3 grams three times daily for 2 weeks modestly reduces SBP and DBP elevations following a 2-hour exposure to TRAP during an outdoor walk compared with taking placebo (110383). Doses have included 4-24 grams daily, with the best evidence of benefit for doses of less than 9 grams daily, for 2-24 weeks (7818,10636,31871,31923,32167,32201,110383,110384).
• Necrotizing enterocolitis (NEC). Oral L-arginine may help prevent NEC in premature infants. Details: In a meta-analysis of 3 clinical trials, L-arginine 260 mg/kg orally in a single dose or two divided doses daily reduces the absolute risk of NEC in premature infants by about 62% when compared with placebo. To prevent one case of NEC, 6 infants would need to be treated with L-arginine (8474,91194,96803).
• Peripheral arterial disease (PAD). Short-term use of intravenous or oral L-arginine may improve symptoms of PAD, but long-term use does not seem to be beneficial. Details: Clinical research shows that using L-arginine intravenously or orally for up to 8 weeks increases flow-mediated dilation and improves symptoms of intermittent claudication associated with PAD (3465,31857,31905). However, long-term administration of L-arginine orally for up to 6 months does not improve walking speed, walking distance, or absolute claudication distance in patients with PAD and intermittent claudication (31957,31985).
• Pre-eclampsia. Intravenous L-arginine may have beneficial effects in pre-eclampsia. However, it is unclear if oral L-arginine is effective. Details: One small clinical study shows that intravenous L-arginine 30 grams as a one-time dose decreases systolic blood pressure (SBP) by 5 mmHg and diastolic blood pressure by 11 mmHg when compared to baseline in pregnant patients with hypertension or pre-eclampsia (31847), while intravenous L-arginine 20 grams daily for 5 days decreases SBP and DBP by about 2% when compared with placebo (31978). Another small clinical study shows that oral use of L-arginine 3 grams daily for 3 weeks reduces SBP and DBP by around 7 and 5 mmHg, respectively, when compared with placebo (31938); however, taking L-arginine 12 grams daily by mouth for 5 days does not seem to improve blood pressure in these patients (11828). Another preliminary clinical trial allowing for both oral and intravenous dosing shows that taking L-arginine 3.5 grams by mouth every 6 hours or 10 grams via intravenous infusion every 8 hours shortly before or immediately after delivery and continuing until postpartum day 3 does not improve blood pressure when compared with placebo (31959). The reasons for the disparate findings are unclear, but the small study sizes, as well as variations in the dose, duration, and timing of therapy before and/or after delivery, may explain some of the differences. Oral L-arginine has also been evaluated for the prevention of pre-eclampsia. One clinical study in patients at high risk for pre-eclampsia shows that taking L-arginine 3 grams daily starting the 20th week of gestation reduces the risk of pre-eclampsia by about 74% when compared with placebo (96811). Based on these results, one case of pre-eclampsia is prevented for every 6 high-risk pregnant patients treated with L-arginine 3 grams daily. Another clinical study also shows that taking two bars of a specific medical food (Heart Bars, Nellson Nutraceutical) containing L-arginine 6.6 grams and antioxidant vitamins daily starting at 14-32 weeks gestation and continuing until delivery reduces the risk of pre-eclampsia by 44% when compared with a bar containing antioxidant vitamins alone in patients at high risk of pre-eclampsia (91197). Based on these results, one case of pre-eclampsia is prevented for every 11 high risk patients treated with this L-arginine-containing medical food.
• Pregnancy-induced hypertension. Intravenous L-arginine may have beneficial effects in pregnancy-induced hypertension. Details: Some clinical research in patients with pregnancy-induced hypertension shows that intravenous infusion of L-arginine 20 grams daily for up to 5 days decreases systolic blood pressure by 2% to 3% and diastolic blood pressure by about 3% when compared with placebo (31933,31961,31978). Clinical research in patients with pre-existing hypertension has also been conducted. One clinical trial shows that taking L-arginine 4 grams by mouth daily for 10-12 weeks does not seem to reduce blood pressure in those with pre-existing hypertension or mild gestational hypertension. However, these results are confounded by the fact that more patients taking placebo needed to be placed on antihypertensive therapy during the study. L-arginine reduced the risk of being placed on antihypertensive drug therapy during the pregnancy by 47% when compared with placebo (32191). Based on this study, for every 5 patients with pregnancy-induced hypertension treated with L-arginine over placebo, antihypertensive drug therapy is avoided in one additional patient. L-arginine has also been investigated in combination with other ingredients in patients with pre-existing hypertension. Preliminary clinical research in patients with pre-existing hypertension and a previous history of pre-eclampsia, stillbirth, intrauterine growth restriction (IUGR), or other placenta vascular disorder shows that taking L-arginine and other ingredients starting at 14 weeks gestation prevents an increase in blood pressure and reduces the percentage of patients requiring new antihypertensive medication by about 73% compared with 24.5% of those not taking this combination. In this study, L-arginine 3 grams daily was taken with magnesium 350 mg and salicylate 100 mg. Therefore, the effect of L-arginine alone is unclear. All patients in the study were taking low dose aspirin 100 mg daily (110382).

POSSIBLY INEFFECTIVE

• Chronic kidney disease (CKD). Oral or intravenous L-arginine does not seem to improve CKD. Details: Most preliminary clinical research shows that taking L-arginine, either orally for up to 6 months or intravenously short-term, does not improve kidney function, glomerular filtration rate, or renal plasma flow in patients with CKD, although proteinuria may be reduced in some patients (31844,31904,32235,32303).
• Hypercholesterolemia. Oral L-arginine does not seem to reduce cholesterol levels. Details: Preliminary clinical research in patients with hypercholesterolemia shows that taking L-arginine 21 grams daily for 4 weeks does not reduce plasma lipids (1363). Furthermore, meta-analyses of clinical research show that taking L-arginine for up to about 6 months does not reduce total or low-density lipoprotein (LDL) cholesterol levels in populations of healthy individuals or those with cardiovascular disease risk factors. However, there was a very small effect on fasting triglyceride levels (102590,102591).
• Myocardial infarction (MI). Oral L-arginine does not seem to improve outcomes after MI. Details: Patients who have had an ST-segment MI who take L-arginine within 24 hours to 21 days, titrated up to a dose of 3 grams three times a day for up to 6 months, do not seem to have reduced vascular stiffness or increased ejection fraction (13221,32137). Also, there is some concern that long-term use of L-arginine might actually worsen outcomes and increase mortality in these patients (13221). Population studies also suggest that intake of L-arginine does not reduce the risk of experiencing an acute coronary event such as MI or coronary heart disease-related mortality (3332,6896,7821,10637).
• Tuberculosis. Oral L-arginine does not seem to improve symptoms or the clearance of tuberculosis infection. Details: Clinical research shows that taking L-arginine (ArgimaxH) 6 grams daily orally for 8 weeks, with or without vitamin D, does not improve symptoms of tuberculosis or the clearance of tuberculosis infection when used with standard treatment (91196).
• Wound healing. Oral L-arginine does not seem to improve wound healing. Details: Clinical research shows that taking L-arginine (as arginine aspartate) 17 grams orally in three divided doses daily for 2 weeks does not improve epithelialization in healthy, elderly patients with catheter wounds, although it may improve collagen deposition (32247). Also, taking L-arginine (as L-arginine hydrochloride) 26 grams daily for 5 days perioperatively does not improve angiogenesis, re-epithelialization, or neutrophil count in patients undergoing skin graft donation when compared with placebo (20692). In addition, taking a wound-specific oral nutrition supplement containing L-arginine 4.5 grams, zinc, and vitamin C twice daily for 4 weeks, along with standard wound care for 8 weeks, is no more effective for wound healing than a standard oral nutrition supplement along with standard wound care (90198). L-arginine has also been studied in combination with other ingredients. Taking L-arginine enterally or orally, before or after surgery, in combination with ribonucleic acid (RNA) and either eicosapentaenoic acid (EPA) or fish oil, seems to improve wound healing when compared with a control group (5531,32174). Another observational study conducted in Italy in newborns shows that applying a specific topical powder containing L-arginine, arnica extract, zinc oxide, and other ingredients (Cicaben, Orsana Italia S.r.l.) to the newborn's umbilical cord stump 3 to 4 times daily until stump detachment reduces the rates of mild complications 48 hours after discharge such as a wet cord stump but does not change the time to cord stump detachment or the rates of purulent secretions or umbilical granulomas when compared with standard dry care. However, no differences were noted between the groups one week after discharge (113662). The validity of these results is limited by the observational nature of the study and the ability of the parents to select a treatment group. It is unclear if the effects in these studies are due to L-arginine, other ingredients, or the combination.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acute respiratory distress syndrome (ARDS). Small clinical studies suggest that oral L-arginine may prevent ARDS. Details: A meta-analysis of three small studies shows that taking L-arginine 3 grams daily, starting in the second or third trimester usually until delivery, reduces the risk of ARDS in the infant by about 54% when compared to control, including placebo or no treatment (110379).
• Altitude sickness. It is unclear if oral L-arginine is beneficial in patients with altitude sickness. Details: Preliminary clinical research shows that taking L-arginine 4 grams orally three times daily for 2 days while ascending to a high altitude and for 24 hours while at high altitude does not reduce altitude sickness when compared with placebo (31955).
• Anthracycline cardiotoxicity. Although there is interest in using oral L-arginine for anthracycline cardiotoxicity, there is insufficient reliable information about the clinical effects of L-arginine for this purpose.
• Anemia of chronic disease. It is unclear if oral L-arginine is beneficial for anemia in patients with chronic kidney disease. Details: One very small clinical study in elderly adults with chronic kidney disease and anemia shows that taking L-arginine orally 1.3 grams daily might increase hemoglobin and erythropoietin levels in some patients when compared to baseline (31988). The validity of these findings is limited by the small study size and the lack of a comparator group.
• Asthma. It is unclear if oral L-arginine is beneficial in patients with asthma. Details: Preliminary clinical research in adults with severe asthma shows that taking L-arginine 0.05 gram/kg ideal body weight twice daily does not reduce asthma exacerbations when compared with placebo (104223). This study may have been inadequately powered to detect a difference in exacerbation rates between groups. While other studies have shown adverse airway effects in patients with asthma (121,31849), this study demonstrated no change in exacerbations and reported no adverse airway effects.
• Athletic performance. Small clinical studies suggest that oral L-arginine may improve measures of athletic performance. Details: A meta-analysis of 5 small clinical trials shows that taking L-arginine seems to modestly improve measures of cardiorespiratory fitness, as measured by a 0.07 L/minute increase in maximal oxygen uptake, when compared with control (105064). L-arginine has also been examined for its effects on athletic performance. Most research suggests that taking L-arginine does not improve athletic performance. However, clinical trials are small and may not be adequately powered to detect a difference in these outcomes Taking L-arginine as a single dose of 5 or 6 grams or as 5-10 grams daily for 2-4 weeks does not improve grip strength, strength during resistance exercise, power output during cycling, or muscle function during recovery from intense resistance exercise in healthy adults (91190,97393,99265,110381,110389). Also, taking L-arginine 5 grams daily for 4 weeks (Bioarginina Farmaceutici Damor) or 8 grams daily for 8 days does not increase swim speed (110381,110386). In contrast, some research suggests that drinking a single beverage containing the same dose of L-arginine 6 grams increases the time to exhaustion during high-intensity exercise when compared with placebo (32180). Also, a meta-analysis of small clinical trials shows that supplementation with L-arginine has a large beneficial effect on aerobic performance and a small beneficial effect on anaerobic performance. However, publication bias was evident in the aerobic performance data, limiting these conclusions. Doses found to be beneficial in this analysis included an acute dose of L-arginine 0.15 gram/kg 60-90 minutes before performance or chronic dosing of 1.5 grams to 2 grams daily for 4-7 weeks for aerobic performance. The chronic dose of L-arginine most likely to be beneficial for anaerobic performance is unclear from this analysis due to inclusion of studies using arginine alpha-ketoglutarate (110395). With the exception of a few studies which include a very small number of healthy females (99265,110395,110386), research on the use of L-arginine for athletic performance has focused almost exclusively on healthy males. Also, studies are heterogeneous with respect to sport and endpoints. Therefore, whether results can be applied to females or specific athletes is unclear. L-arginine has also been evaluated in overweight males. One small clinical study shows that taking a single dose of L-arginine 6 grams 90 minutes prior to high-intensity interval training seems to improve exercise tolerance by improving ventilation, heart rate, and oxygen uptake when compared with placebo (105060). L-arginine has also been evaluated in combination with other ingredients. Research in male soccer players shows that taking L-arginine 1.2 grams and L-citrulline 1.2 grams daily for 7 days increases total power output over a 10-minute cycling test and improves subjective perceptions of exertion when compared with placebo (100956). Another study shows that taking L-arginine 1.5 or 3 grams daily, in combination with grape seed extract, increases physical working capacity at fatigue threshold when compared with pretreatment in untrained, college-aged males (32164).
• Beta-thalassemia. It is unclear if oral L-arginine is beneficial in children with beta-thalassemia. Details:Preliminary clinical research in children aged 6-18 years treated conventionally for pulmonary hypertension related to beta-thalassemia shows that taking L-arginine 0.1 mg/kg daily for 60 days reduces Doppler echocardiography pulmonary arterial pressure by 35% compared with baseline. This measurement was increased by up to 15% in children given conventional treatments only; however, a statistical comparison between these treatment groups was lacking (110391).
• Breast cancer. It is unclear if oral L-arginine is beneficial in patients with breast cancer. Details: Preliminary clinical research shows that taking L-arginine 30 grams daily for 3 days prior to chemotherapy does not improve the clinical response rate in breast cancer patients when compared with placebo (32282).
• Cognitive impairment. It is unclear if oral L-arginine is beneficial in patients with cognitive impairment. Details: A small clinical trial in frail adults aged 65 years of age and up with hypertension shows that taking L-arginine (Bioarginina) 1.66 grams twice daily for 4 weeks modestly improves cognitive function when compared to placebo (110385).
• Congestive heart failure (CHF). It is unclear if oral L-arginine is beneficial in patients with CHF. Details: One small clinical study in patients with CHF stage 2-3 shows that taking L-arginine 15 grams daily for 5 days, in combination with conventional treatment, seems to improve glomerular filtration rate (GFR), creatinine clearance, and sodium and water elimination after saline loading, indicating an improvement in kidney function (3596).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral L-arginine is beneficial in patients with severe COVID-19 infection. Details: A small clinical trial in patients with severe COVID-19 shows that receiving oral L-arginine (Argin, Nutrigrow, India) 3 grams daily for a maximum of 10 days while on oxygen support does not affect the percentage of patients weaned off oxygen support after 10 days, the length of time requiring oxygen support, the duration of hospitalization, or the incidence of adverse thrombotic events, compared with placebo (110392). This study may not have been adequately powered to detect differences between groups. An interim analysis of a small clinical trial in patients hospitalized with severe COVID-19 shows that adding oral L-arginine (Bioarginina, Farmaceutici Damor) 1.66 grams twice daily to standard therapy throughout hospitalization increases the rate of respiratory support reduction by 60% after 10 days of therapy, but not after 20 days of therapy, when compared with placebo. L-arginine also significantly reduced the length of hospital stay. The median hospital stay was 25 days and 46 days, respectively, for L-arginine and placebo (106500). L-arginine has also been investigated in combination with other ingredients for post-acute COVID symptoms. Preliminary clinical research in adults with persistent fatigue following a COVID infection shows that taking L-arginine 1.66 grams plus vitamin C 500 mg (Bioarginina C, Farmaceutici Damor) twice daily for 28 days increases the distance walked in 6 minutes by 30 meters and reduces the percentage of patients with fatigue by about 89%, when compared with placebo. Grip strength was also increased (110390).
• Coronary artery bypass graft (CABG) surgery. It is unclear if oral L-arginine is beneficial for preventing complications after CABG surgery. Details: Preliminary clinical research shows that venous infusion of L-arginine hydrochloride 30 grams as a 10% solution over 15 minutes helps maintain mean arterial pressure, coronary vascular resistance, and graft blood flow when compared with a placebo infusion in patients that have undergone CABG (31840). Administering L-arginine 7.5 grams in 500 mL of cardioplegic solution also seems to reduce wedge pressure and intensive care unit stay in patients undergoing CABG; however, it does not reduce hospital stay duration or postoperative complications when compared with cardioplegic solution alone (31958,31886).
• Critical illness (trauma). Oral L-arginine has only been evaluated in combination with other ingredients; its effects when used alone are unclear. Details: A meta-analysis of clinical research shows that taking L-arginine orally with glutamine, nucleotides, and omega-3 fatty acids reduces the recovery time, the need for ventilation, and infection rates in critically ill patients, but does not reduce the risk of mortality (31853).
• Cyclosporine-induced nephrotoxicity. Although there is interest in using oral L-arginine for cyclosporine-induced nephrotoxicity, there is insufficient reliable information about the clinical effects of L-arginine for this purpose.
• Cystic fibrosis. It is unclear if oral L-arginine is beneficial in patients with cystic fibrosis. Details: Preliminary clinical research in teens and adults with cystic fibrosis shows that twice daily inhalation with L-arginine 500 mg for 2 weeks does not improve lung function when compared with inhaling 2.6% hypertonic saline twice daily (96807).
• Dental caries. Small clinical studies suggest that using a dentifrice containing L-arginine might prevent dental caries. Details: A meta-analysis of small studies shows that use of a dentifrice containing L-arginine 1.5% w/w in combination with calcium base (Dical or calcium carbonate) and fluoride 1450 ppm 2-3 times daily for up to 2 years reduces the risk of developing dental caries by a small to moderate amount when compared with a dentifrice containing only fluoride in children and adults (96806). Also, preliminary clinical research shows that using a confection containing an L-arginine complex (CaviStat) for one year reduces the number of dental caries in molars of children when compared with a sugarless mint control (32011). L-arginine has also been investigated as a prebiotic in combination with probiotics. In 5- to 9-year-old children with low caries risk, clinical research shows that taking one lozenge daily for 10-12 months containing arginine 20 mg along with Lacticaseibacillus paracasei and Lacticaseibacillus rhamnosus, modestly reduces caries severity, but does not reduce caries progression, active caries lesions, plaque, or gingivitis, when compared with placebo (113241,113242).
• Dental hypersensitivity. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that using a toothpaste containing L-arginine, calcium, and fluoride twice daily reduces dentin hypersensitivity when compared with pretreatment or control (32130,32131,32132,32177). Another moderate-sized clinical study in adults shows that applying a topical combination of L-arginine 10% and ibuprofen to tooth enamel surfaces for 10 minutes prior to in-office tooth bleaching reduces the risk and intensity of tooth sensitivity when compared with placebo (115354). It is unclear whether the effects are due to L-arginine, other ingredients, or the combination.
• Diabetes. Small, low-quality studies suggest that oral L-arginine does not improve glycemic control in people with type 2 diabetes. Details: A meta-analysis of small, low-quality studies shows that taking L-arginine 2-20 grams daily for up to 77 weeks decreases fasting blood glucose and serum insulin levels in adults without diabetes. However, no improvements occurred in adults WITH type 2 diabetes. This may be explained by previous studies which suggest L-arginine affects glucose control only in the early steps of beta-cell dysfunction. L-arginine did not improve insulin resistance or glycated hemoglobin (HbA1c) in patients with or without diabetes (104225). Also, a prospective observational study in patients with type 1 or type 2 diabetes has found that taking a specific product (Flebotrofine, AMNOL Chimica Biologica) containing L-arginine for 3 months is not associated with improvements in HbA1c, cholesterol, or triglyceride levels when compared with baseline. Other ingredients in this product included diosmin, troxerutin, hesperidin, black currant extract, and gotu kola extract (108151). The validity of these findings is limited by the lack of a comparator group.
• Diabetic foot ulcers. It is unclear if oral or subcutaneous L-arginine is beneficial in patients with diabetic foot ulcers. Details: A very small clinical study shows that administering L-arginine subcutaneously at the site of diabetic foot ulcers does not decrease healing time or rate of amputation when combined with conventional therapies (14914). Also, taking a specific drink containing L-arginine 7 grams, L-glutamine 7 grams, and calcium hydroxymethylbutyrate (HMB) 1.5 grams (Juven/Abound, Abbott Nutrition) orally twice daily for 16 weeks does not improve diabetic foot ulcer healing when compared with a control drink in non-ischemic patients or those with normal albumin levels. However, in specific populations with low albumin and/or poor limb perfusion, up to 74% more patients had total wound healing when compared with the control drink (96637).
• Diabetic neuropathy. It is unclear if oral L-arginine is beneficial in patients with diabetic neuropathy. Details: Preliminary clinical research shows that taking L-arginine 3 grams daily for 3 months does not improve circulation, disability, or nerve function in patients with diabetic neuropathy when compared with placebo (32145).
• Head and neck cancer. It is unclear if oral L-arginine is beneficial in patients with head and neck cancer. Details: Small clinical studies suggest that enteral nutrition supplemented with L-arginine does not seem to have any beneficial effects on markers of immune function such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), length of postoperative hospital stay, or fistula rates; however, it seems to reduce wounds and general infections after surgery in patients with head and neck cancer when compared with control (10160,32008).
• Heart failure. It is unclear if oral L-arginine is beneficial in patients with heart failure. Details: Preliminary clinical research in adults with heart failure shows that taking L-arginine 3.0-12.6 grams orally daily for 6-12 weeks does not consistently improve exercise tolerance or peripheral vascular resistance (3595,6028,32138). However, some research shows that taking L-arginine 1000 mg three times daily for 10 weeks modestly improves measures of cardiac function compared with placebo (110380). Although some research disagrees (32138), most research shows that taking L-arginine modestly improves quality of life (3595,110380).
• Heart transplant complications. It is unclear if oral L-arginine is beneficial in patients that have received a heart transplant. Details: Preliminary clinical research shows that taking L-arginine 6 grams orally twice daily for 6 weeks increases walking distance and oxygen uptake and delays the ventilatory threshold in heart transplant patients when compared with baseline (32150).
• HIV/AIDS-related wasting. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical study in patients with HIV/AIDS shows that taking L-arginine orally, in combination with hydroxymethylbutyrate (HMB) and glutamine for 8 weeks, increases body weight, particularly lean body mass, and positively affects immune status when compared with placebo (1909). However, other clinical research in HIV-positive patients shows that taking L-arginine 7.4 grams daily orally, in combination with omega-3 fatty acids and a balanced oral nutritional supplement for 6 months, does not improve body weight or fat mass, total energy intake, or immune status when compared to taking the nutritional supplement alone (113).
• Impaired glucose tolerance (prediabetes). It is unclear if oral L-arginine can prevent the development of type 2 diabetes in adults with prediabetes. Details: Clinical research shows that taking L-arginine (Bioarginine, Farmaceutici Damor) 3.2 grams orally twice daily for 18 months does not reduce the incidence of diabetes in patients with impaired glucose tolerance (prediabetes). However, when assessed one year after treatment discontinuation, patients who took L-arginine had a 58% lower risk of developing diabetes when compared with placebo (91195).
• Infertility. It is unclear if oral L-arginine improves outcomes in people undergoing an assisted reproductive technology (ART) program. Details: Some preliminary clinical research shows that taking L-arginine 16 grams daily decreases the cancellation rate of in vitro fertilization (IVF) and increases the number of oocytes collected in females undergoing an ART program when compared with control. However, taking L-arginine does not seem to improve the number of viable pregnancies (31842). A small clinical study of females undergoing an ART program shows that taking a combination product containing L-arginine 1 gram with folate 200 mcg or L-arginine 2 grams, folate 400 mcg, and vitamin E 10 mg daily for 12 weeks does not affect the hCG-positive rate or clinical pregnancy rate when compared with placebo. A subgroup analysis suggests that taking these combination products might improve HCG-positive and clinical pregnancy rates in females who are undergoing ART due to male infertility (104224). However, this small study was not adequately powered to detect a difference in these outcomes, limiting the validity of these findings.
• Interstitial cystitis. Small clinical studies suggest that oral L-arginine may improve pain in interstitial cystitis. Details: Taking L-arginine orally seems to reduce some symptoms, especially pain, that are associated with interstitial cystitis (107,114,3460,31855,32267). Research shows that patients with interstitial cystitis having a bladder capacity greater than 800 mL and/or a history of recurrent genitourinary infections might respond more favorably to L-arginine than patients with bladder capacity less than 800 mL and/or no history of recurrent genitourinary infections. Three months of treatment may be necessary before significant symptom improvement occurs (3460). However, L-arginine does not seem to reduce the need to urinate at night or improve urgency or frequency of urination (3460,31855).
• Intrauterine growth restriction (IUGR). Small clinical studies suggest that oral or intravenous L-arginine may increase birthweight in IUGR. Details: A meta-analysis of mainly small studies shows that L-arginine given orally or intravenously in the third trimester for a time period of 7 days or until delivery increases the birthweight by up to 650 grams in patients with an IUGR pregnancy. Furthermore, there is evidence from a small number of these studies that L-arginine supplementation decreases the risk of neonatal respiratory distress syndrome and fetal intracranial hemorrhage (96804). A more recent meta-analysis of small studies also shows that taking L-arginine 3 grams daily, starting in the second or third trimester usually until delivery, reduces the risk of an IUGR infant by about 32% when compared to control, including placebo or no treatment (110379). Doses used in clinical research have usually been 3 grams daily orally, although some studies have used up to 20 grams intravenously (31930,31937,96804,110379). However, supplementation with L-arginine does not seem to increase birthweight or reduce neonatal mortality or morbidity when compared with placebo in patients with severe IUGR (32083).
• Kidney transplant. Small clinical studies suggest that oral L-arginine may not improve kidney function in patients after kidney transplantation. Details: Although preliminary clinical research showed some benefit, evidence from other clinical research shows that infusion with L-arginine does not increase renal plasma flow or glomerular filtration rate in kidney transplant patients treated with cyclosporine, including those experiencing transplant dysfunction (112,31876,32229). Other evidence suggests that intravenous L-arginine improves kidney function only in transplant patients receiving organs with a short cold ischemia time or those receiving kidneys from young donors (31887).
• Male infertility. It is unclear if oral L-arginine is beneficial in males with infertility. Details: Preliminary clinical research shows that taking L-arginine 4 grams daily for 12 weeks does not improve semen quality in males with oligospermia when compared with placebo (32209). However, one small clinical study shows that a specific formulation of L-arginine aspartate and maritime pine bark extract (Prelox), taken for 6 months, improves sperm quality in males with idiopathic male infertility when compared to baseline (32061). The validity of this finding is limited by the lack of a comparator group. Additionally, it is unclear if this effect is due to L-arginine, maritime pine bark, or the combination.
• Mitochondrial myopathies. Small clinical studies suggest that intravenous L-arginine may modestly improve symptoms in patients with MELAS (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes syndrome). Details: Preliminary clinical research shows that infusions of L-arginine, 0.5 grams/kg administered within one hour of stroke-like symptoms, improves headaches, nausea, vomiting, transient blindness, and the appearance of bright spots when compared to pretreatment in patients with MELAS (31943,99263). Also, taking oral L-arginine 4-24 grams daily for 18 months seems to reduce the frequency and severity of stroke-like symptoms associated with MELAS when compared to baseline (31943). However, other preliminary clinical research shows that taking oral L-arginine 0.3-0.5 grams/kg daily in three divided doses for 2 years does not reduce the severity of MELAS symptoms, including migraine and stroke-like episodes. If a stroke-like episode did occur, administration of intravenous L-arginine 0.5 grams/kg improved headache, nausea, vomiting, and visual disturbance (99263). The validity of this research is limited by the small study sizes and the absence of comparator groups.
• Migraine headache. Although there is interest in using oral L-arginine for migraine, there is insufficient reliable information about the clinical effects of L-arginine for this condition.
• Muscular dystrophy. There is limited evidence on the oral use of L-arginine in patients with Duchenne muscular dystrophy. Details: A very small study in five children with Duchenne muscular dystrophy, shows that drinking a beverage containing L-arginine hydrochloride (L-Arginine Hydrochloride, Selectchemie) 2.5 grams three times daily, in addition to metformin 250 mg twice daily, for 16 weeks improves motor function by 4% and increases distance walked in two minutes by 9.6 meters when compared to baseline (96805). The validity of these findings is limited by the very small study size and lack of a comparator group.
• Nitrate tolerance. It is unclear if oral L-arginine is beneficial for nitrate tolerance. Details: A very small crossover study in adults with stable angina shows that taking L-arginine orally 700 mg four times daily for up to 10 days seems to prevent tolerance to transdermal nitrate when compared with placebo (8475).
• Obesity. Small clinical studies suggest that oral L-arginine may be beneficial for weight loss. Details: A meta-analysis of mainly small clinical trials shows that taking L-arginine daily for at least 8 weeks modestly reduces body weight, body mass index (BMI), and waist circumference when compared with placebo. However, when taking L-arginine for less than 8 weeks, BMI and body weight were not affected. The optimal dose of L-arginine was 2-6 grams (110398). An additional small clinical study suggests that taking a specific arginine supplement (NOW Foods) 3 grams by mouth three times daily for 12 weeks, in addition to receiving dietary counseling, reduces waist circumference by 4-6 cm and reduces body weight by 1.8-2.9 kg when compared to baseline in obese females 18-40 years of age (91193). The validity of these findings is limited by the lack of a comparator group.
• Oral mucositis. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study shows that taking a specific combination of L-arginine 7 grams, L-glutamine 7 grams, and hydroxymethylbutyrate (HMB) 1.2 grams (Abound; Abbott) in water twice daily during chemoradiotherapy treatment for head and neck cancer does not reduce the incidence of severe oral mucositis when compared with a historical control (99243). The validity of this finding is limited by the lack of a placebo control. Additionally, a small open-label study in patients undergoing chemoradiation for head and neck cancer shows that taking a specific combination product (Abound, Abbot) containing L-arginine, glutamine, and HMB twice daily throughout chemoradiation treatments decreases the incidence of grade 3 or higher oral mucositis and ameliorates body weight loss when compared with no intervention (113726). However, the incidence of grade 2 or higher oral mucositis was not reduced. It is unclear if this effect is due to L-arginine, other ingredients, or the combination. Additionally, the validity of the study is limited by the lack of blinding.
• Periodontitis. It is unclear if oral L-arginine is beneficial in patients with periodontitis. Details: Preliminary clinical research in patients with chronic periodontitis shows that using L-arginine aspartate (Yuria-Pharm, Ukraine) 1 gram three times daily orally for 10 days after scaling and root planing, modestly reduces bleeding on probing but not periodontal pocket depth, when compared with untreated controls (108926).
• Physical performance. It is unclear if oral L-arginine is beneficial for improving physical performance in older adults. Details: A small study in physically active females 65 years of age and older shows that taking L-arginine 8 grams as a single dose does not improve lower body strength, measured by knee flexion and extension tests, or functional performance, measured by sit-stand, tandem gait, and timed up-and-go tests, when compared with placebo (96812).
• Polycystic ovary syndrome (PCOS). Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a combination of N-acetylcysteine 1200 mg daily plus L-arginine 1600 mg daily for 6 months modestly improves menstrual function and decreases insulin resistance in patients with PCOS when compared to baseline (32094). The validity of these findings is limited by the lack of a comparator group.
• Postoperative infection. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Small clinical studies show that taking L-arginine, enterally or orally, either before or after surgery, in combination with fish oil, or with ribonucleic acid (RNA) and eicosapentaenoic acid (EPA), seems to reduce the rate of perioperative infection when compared with a control group. The risk of infection was 41% lower when compared to taking no arginine-based formulations. However, there is no good evidence to support the use of L-arginine alone for this purpose, and it is possible that this effect is due to the other ingredients or the combination of ingredients (5531,32174,32196).
• Postoperative recovery. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Small clinical studies show that taking L-arginine, enterally or orally, either before or after surgery, in combination with fish oil, or with ribonucleic acid (RNA) and eicosapentaenoic acid (EPA), seems to reduce the recovery time after surgery or serious illness when compared with a control group. This seems to be related to a reduced number of perioperative infections and improved wound healing. However, there is no good evidence to support the use of L-arginine alone for this purpose, and it is possible that this effect is due to the other ingredients or the combination of ingredients (5531,32174,32196). The effect of another combination product containing L-arginine is unclear. In one clinical study, taking a combination product (Abound, Abbott) containing L-arginine 7 grams, glutamine 7 grams, and hydroxymethylbutyrate 1.2 grams orally daily for 3 days before and 7 days after abdominal surgery did not reduce the incidence of wound infection or other complications when compared with placebo (99413). However, when a similar combination of L-arginine 14 grams, glutamine 14 grams, and hydroxymethylbutyrate 3 grams (Heallagen) was taken orally daily for one month before heart surgery, the length of hospital and ICU stay were reduced by about one day. Recovery, based on some but not all biochemical or other measurements, was also improved. However, there was no difference in risk of overall postoperative complications (110394). The discrepancies between these two studies may be related to differences in the dose or duration of the combination product and/or the type of surgery.
• Pressure ulcers. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Oral L-arginine has been evaluated in combination with other ingredients for the treatment of grade II-IV pressure ulcers. Two small clinical studies in hospitalized patients show that administering an oral nutritional supplement enriched with L-arginine, zinc, and vitamin C improves ulcer healing when compared with a standard diet (31953,87173). A small preliminary clinical study in sedentary older adults in care facilities shows that giving an oral or enteral combination of L-arginine 7.4 grams, L-glutamine 7.4 grams, and hydroxymethylbutyrate (HMB) 1.3 grams (Abound, Abbott) daily for 20 weeks reduces median time to healing by 48 days when compared with standard care only (110396). Also, preliminary clinical research in patients living in long-term care facilities with grade II-IV pressure ulcers shows that taking an oral nutritional supplement enriched in protein, energy, L-arginine, vitamin C, and zinc daily for 9 weeks reduces ulcer area and decreases oozing when compared to baseline (32045). The validity of this finding is limited by the lack of a comparator group.
• Preterm labor. Small clinical studies suggest that oral L-arginine may prevent preterm labor. Details: A meta-analysis of three small studies shows that taking L-arginine 3-6.6 grams daily, starting in the second or third trimester usually until delivery, reduces the risk of preterm labor by about 50% when compared to control, usually placebo (110379).
• Pulmonary hypertension. It is unclear if oral L-arginine is beneficial in children with pulmonary hypertension related to beta-thalassemia. Details: Preliminary clinical research in children aged 6-18 years treated conventionally for pulmonary hypertension related to beta-thalassemia shows that taking L-arginine 0.1 mg/kg daily for 60 days reduces Doppler echocardiography pulmonary arterial pressure by 35% compared with baseline. This measurement was increased by up to 15% in children given conventional treatments only; however, a statistical comparison between these treatment groups was lacking (110391).
• Radiation dermatitis. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with head and neck cancer shows that taking a combination of L-arginine 7 grams, L-glutamine 7 grams, and hydroxymethylbutyrate (HMB) 1.2 grams (Abound, Abbott) in water twice daily from the first day of radiation to approximately 1 week after completion does not reduce the number of patients with severe dermatitis when compared with taking no supplement. However, there was a 34% reduction in the incidence of moderate dermatitis and the overall duration of dermatitis was reduced (96639).
• Restenosis. It is unclear if intravenous L-arginine helps to prevent restenosis after stent implantation. Details: Some clinical research suggests that intravenous and intracoronary infusion of L-arginine during stent implantation followed by oral L-arginine for 2 weeks does not reduce the risk of restenosis when compared with placebo (31925). However, local delivery of 6 mL of L-arginine 100 mg/mL for 15 minutes after stent deployment seems to reduce neointimal formation at 6 months after stent placement when compared with placebo (31883).
• Respiratory tract infections. Although there is interest in using oral L-arginine for respiratory tract infections, there is insufficient reliable information about the clinical effects of L-arginine for these conditions.
• Schizophrenia. It is unclear if oral L-arginine is beneficial in patients with schizophrenia. Details: A small clinical study shows that taking L-arginine 3 grams twice daily for 3 weeks, in conjunction with an individualized medication regimen, does not improve positive, negative, or depressive symptoms associated with schizophrenia when compared with taking the medication regimen alone (99264).
• Sexual dysfunction. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in females with sexual dysfunction who are taking oral contraceptives shows that taking a specific combination product (Lady Prelox, Horphag Research) containing L-arginine, maritime pine bark extract, L-citrulline, and rose hip extract daily for 8 weeks improves symptoms of sexual dysfunction by 18% when compared with a control group (91963). Taking the same product in a dose of 2 tablets twice daily for 8 weeks, in addition to the lifestyle management program, improves vaginal dryness in pre- and post-menopausal patients when compared with lifestyle management alone (103611). It is unclear if this effect is due to L-arginine, the other ingredients, or the combination.
• Sickle cell disease. Small clinical studies suggest that oral or intravenous L-arginine may modestly improve complications in patients with sickle cell disease. Details: Two small clinical studies in hospitalized children aged 3-19 years with sickle cell disease-related veno-occlusive crisis shows that administering L-arginine intravenously or orally 100 mg/kg three times daily for 5 days or until discharge reduces total opioid use by 26% to 54%, pain scores at discharge by 23%, and median length of hospital stay by about 36 hours when compared with placebo (97392,105063). Another very small clinical study in patients aged 13-63 years with sickle cell disease shows that taking L-arginine 0.1 grams/kg orally three times daily for 5 days reduces pulmonary hypertension when compared to baseline (11428).
• Stress. Oral L-arginine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in healthy adults shows that taking a single dose of L-arginine 50 mg plus L-theanine 200 mg modestly reduces stress associated with a stress-loading test when compared with placebo, but was no more effective than taking L-theanine alone (110393).
• Valproic acid-induced toxicities. Although there is interest in using intravenous L-arginine for valproic acid toxicity, there is insufficient reliable information about the clinical effects of L-arginine for this purpose. More evidence is needed to rate L-arginine for these uses.

(Read more about L-ARGININE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Erectile dysfunction (ED). Preliminary clinical research in middle-aged men with ED shows that taking two capsules of a specific combination product (Revactin, MD Concepts LLC) containing muira puama, ginger root, guarana, and L-citrulline twice daily for 3 months improves scores related to erectile function and intercourse satisfaction, but does not improve sexual desire or orgasmic function scores, when compared to baseline (103224). This study is limited by the lack of a placebo control, the use of per-protocol analysis, and a high dropout rate. In fact, 44% of patients withdrew in order to resume use of phosphodiesterase type 5 (PDE5) inhibitors. Further, it is unclear if these effects are due to muira puama, other ingredients, or the combination.
• Sexual dysfunction. Preliminary clinical research in women with a low sex drive shows that taking 2-6 tablets of a specific combination product (Herbal vX) containing muira puama extract (HV-430) 350-1050 mg and ginkgo extract 32-96 mg modestly improves sexual desire and the frequency of sexual intercourse when compared with baseline (63920). The lack of control group limits the validity of these findings. Further, it is unclear if these effects are due to muira puama, ginkgo, or the combination. More evidence is needed to rate muira puama for these uses.

(Read more about MUIRA PUAMA)

POSSIBLY EFFECTIVE

• Sexual dysfunction. Oral tribulus seems to improve sexual experience in females with hypoactive sexual desire disorder (HSDD) or sexual dysfunction. Some research also shows that oral tribulus improves sexual function in males. Details: Clinical research in premenopausal and postmenopausal patients with HSDD shows that taking tribulus 250 mg three times daily (Androsten, Herbarium) for 3 months improves overall satisfaction and lubrication, as well as pain, desire, sexual arousal, and ability to reach orgasm, when compared with placebo (92027,97331,97332). Other preliminary clinical research in females with HSDD shows that taking tribulus extract 7.5 mg daily for 4 weeks improves sexual desire, arousal, satisfaction, orgasm, pain, and lubrication when compared with placebo (92022). A nonblinded clinical study comparing tribulus dosing regimens shows that taking oral tribulus 280 mg, either once daily or in three divided daily doses, for 90 days results in similar improvements in sexual dysfunction, regardless of menopausal status. However, neither dosing schedule increases clitoral blood flow when compared with baseline (108551). Tribulus has also been studied in males. One clinical study in males with erectile dysfunction, with or without HSDD, shows that taking tribulus (Tribestan, Sopharma AD) 500 mg three times daily for 3 months improves sexual desire and intercourse satisfaction when compared with placebo (97330).

POSSIBLY INEFFECTIVE

• Athletic performance. Oral tribulus does not seem to improve athletic performance. Details: Small clinical studies in athletes show that taking tribulus orally, alone or in combination with other ingredients such as androstenedione, most often as 450-770 mg daily for 5-8 weeks, does not seem to enhance body composition or exercise performance when compared with placebo or a control group (7514,13255,92029,108552).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Angina. It is unclear if oral tribulus is beneficial for angina. Details: Preliminary clinical research shows that taking a tribulus extract orally might reduce symptoms of angina when compared with a control (3931).
• Atopic dermatitis (eczema). Oral tribulus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Some preliminary clinical research shows that taking tribulus orally in combination with 9 other herbs (Zemaphyte) daily for 8 weeks reduces redness and skin lesions in adults and children with nonexudative atopic dermatitis (12627,12628). However, other research shows no effect (12630). It is unclear if these effects are due to tribulus, the other ingredients, or the combination.
• Bacterial vaginosis. Topical tribulus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with bacterial vaginosis shows that using a specific vaginal suppository (Forzajeh) containing tribulus, myrtle, fennel, and tamarind daily for 1 week is as effective as metronidazole vaginal suppository for improving vaginal discharge volume and odor, pelvic pain, cervical inflammation, and vaginal pH (100339). It is unclear if these effects are due to tribulus, the other ingredients, or the combination.
• Benign prostatic hyperplasia (BPH). Oral tribulus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with BPH shows that taking a combination supplement (Prostalyn, East India Pharmaceutical Works Ltd.) containing tribulus 600 mg and curry leaf (Murraya koenigii) 600 mg twice daily for 12 weeks improves prostate symptoms when compared to baseline, with no difference when compared to tamsulosin 400 mcg daily. This supplement also seems to reduce prostate volume by around 2 mL (92033).
• Cancer. Although there is interest in using oral tribulus for cancer, there is insufficient reliable information about the clinical effects of tribulus for this condition.
• Chronic fatigue syndrome (CFS). Although there is interest in using oral tribulus for CFS, there is insufficient reliable information about the clinical effects of tribulus for this condition.
• Diabetes. It is unclear if oral tribulus is beneficial for diabetes. Details: Preliminary clinical research in females with type 2 diabetes who are taking oral hypoglycemic agents shows that taking tribulus extract powder 500 mg twice daily for 3 months modestly reduces fasting glucose and postprandial glucose levels, but not glycated hemoglobin, when compared with placebo. However, the validity of these findings is limited by the difference in diabetes severity between groups at baseline (97327).
• Erectile dysfunction (ED). It is unclear if oral tribulus is beneficial for ED. Research is conflicting. Details: Clinical research in patients with ED shows that taking tribulus (Tribestan, Sopharma AD) 500 mg three times daily for 3 months does not provide a clinically beneficial improvement in erectile function when compared with placebo (97330). Other clinical research shows that taking tribulus 400 mg twice daily for 30 days does not improve erectile function when compared with placebo (92031). However, one preliminary clinical study in patients with partial androgen deficiency shows that taking tribulus 250 mg three times daily for 3 months improves erectile function when compared to baseline (92028). Tribulus has also been studied in combination with other ingredients. Preliminary clinical research shows that taking a combination supplement (Tradamix TX1000, Tradapharma Sagl) containing tribulus 450 mg, brown algae 300 mg, and chitosan 250 mg twice daily for 3 months improves sexual satisfaction, desire, ejaculation function, and sexual quality of life when compared with placebo in patients with mild-to-moderate ED (92030). It is unclear if these effects are due to tribulus, the other ingredients, or the combination.
• Exercise-induced muscle damage. It is unclear if oral tribulus is beneficial for exercise-induced muscle damage. Details: Clinical research in a small number of healthy, untrained males shows that taking tribulus 500 mg daily for 2 weeks prior to performing resistance exercise reduces markers of muscle damage, including creatine phosphokinase (CPK) and lactate dehydrogenase (LDH), but does not reduce levels of the inflammatory markers interleukin-6 (IL-6) or C-reactive protein (CRP), when compared with placebo (103236). However, another small clinical study in male CrossFit athletes shows that taking tribulus 770 mg capsules (Quamtrax Pharmaceuticals) daily for 42 days does not reduce CPK but does improve CRP and oxidant status when compared with placebo (111747). However, it is unclear whether any improvements are clinically significant. A very small crossover clinical study in trained male athletes shows that taking 20 mg/kg/day of tribulus in 3 divided doses 30 minutes before meals with 500 mL of water for 4 weeks does not reduce muscle soreness after intensive aerobic exercise when compared with placebo (111746).
• Gonorrhea. Although there is interest in using oral tribulus for gonorrhea, there is insufficient reliable information about the clinical effects of tribulus for this condition.
• Hypercholesterolemia. Although there is interest in using oral tribulus for hypercholesterolemia, there is insufficient reliable information about the clinical effects of tribulus for this condition.
• Hypertension. It is unclear if oral tribulus can lower blood pressure. Details: In patients with pre-hypertension, clinical research shows that taking powdered tribulus fruit 2 grams three times daily for 2 months reduces systolic and diastolic blood pressure by 6 and 5 mmHg, respectively, when compared with placebo (105245). It is unclear what effect Tribulus may have in patients with diagnosed hypertension.
• Kidney stones (nephrolithiasis). Although there is interest in using oral tribulus for kidney stones, there is insufficient reliable information about the clinical effects of tribulus for this purpose.
• Male infertility. It is unclear if oral tribulus is beneficial for male infertility; the available research is conflicting. Details: Case series suggest that taking a specific tribulus product (Tribestan, Sopharma) 250 mg three times daily for 30 days improves ejaculate volume, sperm concentration, and sperm motility in patients with infertility due to oligoasthenozoospermia (78865), and improves libido and erections in patients with primary hypogonadism (78868). Conversely, a small clinical study in patients with oligozoospermia shows that taking tribulus granules 6 grams daily for 60 days does not improve sperm count when compared with placebo (92032). In patients with idiopathic infertility, taking tribulus 250 mg three times daily for 3 months does not increase sperm concentration, sperm motility, serum testosterone levels, or luteinizing hormone levels (97328). The difference in these findings might be due to the small study sizes, as well as the variable etiology of infertility.
• Menopausal symptoms. Oral tribulus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking a combination product containing tribulus 40 mg, ginger, saffron, and Ceylon cinnamon (Aphrodit, Goldaru Company) twice daily for 4 weeks improves mental and physical symptoms during menopause, but not genitourinary symptoms, when compared with placebo (97326). It is not clear if this effect is due to tribulus, the other ingredients, or the combination.
• Osteoporosis. Although there is interest in using oral tribulus for osteoporosis, there is insufficient reliable information about the clinical effects of tribulus for this condition.
• Polycystic ovary syndrome (PCOS). Oral tribulus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical study shows that taking tribulus extract (Tribulus forte, Mediherb, Integra Healthcare Ltd) 245 mg daily along with other ingredients and lifestyle modification during the follicular phase of the menstrual cycle for 3 months improves some symptoms of PCOS, including a 33% reduction in oligomenorrhea or amenorrhea and a 43-day reduction in the duration between menstrual cycles, when compared with lifestyle modification alone. Taking tribulus with other ingredients also improves quality of life by about 30% and reduces body mass index by 1 kg/m2 when compared with placebo. Although the conception rate increased 4-fold in patients taking the combination product, the live birth rate was similar to those taking placebo. (97216). It is unclear if these effects are due to tribulus, the other ingredients, or the combination.
• Premature ejaculation. Oral tribulus has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a combination product containing tribulus, 5-HTP, winter savory, and chanca piedra (EiacuMev, Farmaceutica Mev) daily for 3 months improves time to ejaculation by 30 seconds and reduces symptoms related to premature ejaculation when compared to control (97016). More evidence is needed to rate tribulus for these uses.

(Read more about TRIBULUS)

LIKELY SAFE ...when used orally or intravenously and appropriately. Calcium is safe when used in appropriate doses (7555,12928,12946,95817). However, excessive doses should be avoided. The Institute of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: Age 0-6 months, 1000 mg; 6-12 months, 1500 mg; 1-8 years, 2500 mg; 9-18 years, 3000 mg; 19-50 years, 2500 mg; 51+ years, 2000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stone, hypercalciuria, hypercalcemia, and milk-alkali syndrome. There has also been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these studies, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Other clinical studies suggest that, when combined with vitamin D supplementation, calcium supplementation is not associated with an increased risk of CVD, CHD, or MI (93533,107231). Other analyses report conflicting results and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Advise patients not to consume more than the recommended daily intake of 1000-1200 mg per day, to consider total calcium intake from both dietary and supplemental sources (17484), and to combine calcium supplementation with vitamin D supplementation (93533).

POSSIBLY UNSAFE ...when used orally in excessive doses. The National Academy of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: 19-50 years, 2500 mg; 51 years and older, 2000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stones, hypercalciuria, hypercalcemia, and milk-alkali syndrome. There has also been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these studies, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Other clinical studies suggest that, when combined with vitamin D supplementation, calcium supplementation is not associated with an increased risk of CVD, CHD, or MI (93533,107231). Other analyses report conflicting results and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Advise patients to not consume more than the recommended daily intake of 1000-1200 mg per day, to consider total calcium intake from both dietary and supplemental sources (17484), and to combine calcium supplementation with vitamin D supplementation (93533).

CHILDREN: LIKELY SAFE
when used orally and appropriately. Calcium is safe when used in appropriate doses (17506).

CHILDREN: POSSIBLY UNSAFE
when used orally in excessive doses. The Institute of Medicine sets the daily tolerable upper intake level (UL) for calcium according to age as follows: 0-6 months, 1000 mg; 6-12 months, 1500 mg; 1-8 years, 2500 mg; 9-18 years, 3000 mg (17506). Doses over these levels can increase the risk of side effects such as kidney stones, hypercalciuria, hypercalcemia, and milk-alkali syndrome.

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately (945,1586,3263,3264,17506). The World Health Organization (WHO) recommends prescribing oral calcium supplementation 1.5-2 grams daily during pregnancy to those with low dietary calcium intake to prevent pre-eclampsia (97347).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in excessive doses. The Institute of Medicine sets the same daily tolerable upper intake level (UL) for calcium according to age independent of pregnancy status: 9-18 years, 3000 mg; 19-50 years, 2500 mg (17506). Doses over these amounts might increase the risk of neonatal hypocalcemia-induced seizures possibly caused by transient neonatal hypoparathyroidism in the setting of excessive calcium supplementation during pregnancy, especially during the third trimester. Neonatal hypocalcemia is a risk factor for neonatal seizures (97345).

(Read more about CALCIUM)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Damiana has Generally Recognized As Safe status (GRAS) for use in foods in the US (4912).

POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts (12,46933,11866).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about DAMIANA)

LIKELY SAFE ...when used orally and appropriately, short-term. Eleuthero root extract 300-2000 mg has been used safely in clinical trials lasting up to 3 months (730,1427,2574,7522,11099,15586,91509). There is insufficient reliable information available about the safety of eleuthero when used long-term.

CHILDREN: POSSIBLY SAFE
when used orally in adolescents aged 12-17 years, short-term. Eleuthero 750 mg three times daily was used for 6 weeks with apparent safety in one clinical trial (75028). There is insufficient reliable information available about the safety of eleuthero in children or adolescents when used long-term.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about ELEUTHERO)

POSSIBLY SAFE ...when horny goat weed extract is used orally and appropriately, short-term. A specific extract of horny goat weed containing 60 mg icariin, 15 mg daidzein, and 3 mg genistein (Xianling Gubao; Tong Ji Tang Pharmacal Company) has been used daily with apparent safety for up to 24 months (14900,97268). Another aqueous extract of horny goat weed containing up to 25.36% icariin has been used in a dose of 300 mL daily with apparent safety for up to 6 months (55452). Another horny goat weed extract has been used with apparent safety at doses up to 1000 mg daily (providing 200 mg icariin) for up to 30 days (108311).

POSSIBLY UNSAFE ...when used orally long-term or in high doses. Long-term use, or taking high doses of some species of horny goat weed, has been linked to serious adverse effects including respiratory arrest (10346).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Horny goat weed might have androgenic activity (10346). Theoretically, it might harm a developing fetus; avoid using.

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about HORNY GOAT WEED)

POSSIBLY SAFE ...when used orally and appropriately. L-arginine has been used safely in clinical studies at doses of up to 24 grams daily for up to 18 months (3331,3460,3595,3596,5531,5532,5533,6028,7815,7816)(8014,8473,13709,31943,91195,91196,91963,99264,99267,110380)(110387). A tolerable upper intake level (UL) for arginine has not been established, but the observed safe level (OSL) of arginine intake established in clinical research is 20 grams (31996). ...when used intravenously and appropriately. Parenteral L-arginine is an FDA-approved prescription product (15). ...when used topically and appropriately. L-arginine appears to be safe when 5 grams is applied as a topical cream twice daily for 2 weeks or when a dentifrice is used at a dose of 1.5% w/w for up to 2 years (14913,96806). ...when inhaled, short-term. L-arginine appears to be safe when inhaled twice daily at a dose of 500 mg for up to 2 weeks (96807).

CHILDREN: POSSIBLY SAFE
when used orally in premature infants and children (8474,32286,96803,97392,110391). ...when used intravenously and appropriately (97392). Parenteral L-arginine is an FDA-approved prescription product (15). ...when used topically, short-term. A dentifrice containing L-arginine appears to be safe when used at a dose of 1.5% w/w for up to 2 years in children at least 3.7 years of age (96806). ...when inhaled, short-term. L-arginine appears to be safe when inhaled twice daily at a dose of 500 mg for up to 2 weeks in children at least 13 years of age (96807).

CHILDREN: POSSIBLY UNSAFE
when used intravenously in high doses. Parenteral L-arginine is an FDA-approved prescription product (15). However, when higher than recommended doses are used, injection site reactions, hypersensitivity reactions, hematuria, and death have occurred in children (16817).

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately, short-term. L-arginine 12 grams daily for 2 days has been used with apparent safety in pregnancy during the third trimester (11828). L-arginine 3 grams daily has been taken safely during the second and/or third trimesters (31938,110379,110382). ...when used intravenously and appropriately, short-term. Intravenous L-arginine 20-30 grams daily has been used safely in pregnancy for up to 5 days (31847,31933,31961,31978).

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about L-ARGININE)

POSSIBLY SAFE ...when used orally and appropriately, short-term. Taking muira puama 500-1050 mg daily, as part of a combination product, has been used with apparent safety for 1 month (63920,103224). There is insufficient reliable information available about the safety of muira puama when used long-term.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about MUIRA PUAMA)

LIKELY UNSAFE ...when the spine-covered fruit is used orally. There have been reports of bilateral pneumothorax and bronchial polyp after oral consumption of the spine-covered fruit (818).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Animal research suggests that tribulus might adversely affect fetal development (12674); avoid using.

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about TRIBULUS)

ALUMINUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Calcium citrate might increase aluminum absorption and toxicity. Other types of calcium do not increase aluminum absorption.  Details Calcium citrate can increase the absorption of aluminum when taken with aluminum hydroxide. The increase in aluminum levels may become toxic, particularly in individuals with kidney disease (21631). However, the effect of calcium citrate on aluminum absorption is due to the citrate anion rather than calcium cation. Calcium acetate does not appear to increase aluminum absorption (93006).

BISPHOSPHONATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Calcium reduces the absorption of bisphosphonates.  Details Advise patients to take bisphosphonates at least 30 minutes before calcium, but preferably at a different time of day. Calcium supplements decrease absorption of bisphosphonates (12937).

CALCIPOTRIENE (Dovonex) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Taking calcipotriene with calcium might increase the risk for hypercalcemia.  Details Calcipotriene is a vitamin D analog used topically for psoriasis. It can be absorbed in sufficient amounts to cause systemic effects, including hypercalcemia (12938). Theoretically, combining calcipotriene with calcium supplements might increase the risk of hypercalcemia.

CALCIUM CHANNEL BLOCKERS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Intravenous calcium may decrease the effects of calcium channel blockers; oral calcium is unlikely to have this effect.  Details Intravenous calcium is used to decrease the effects of calcium channel blockers in the management of overdose. Intravenous calcium gluconate has been used before intravenous verapamil (Isoptin) to prevent or reduce the hypotensive effects without affecting the antiarrhythmic effects (6124). But there is no evidence that dietary or supplemental calcium when taken orally interacts with calcium channel blockers (12939,12947).

CEFTRIAXONE (Rocephin) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = D Co-administration of intravenous calcium and ceftriaxone can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys.  Details Avoid administering intravenous calcium in any form, such as parenteral nutrition or Lactated Ringers, within 48 hours of intravenous ceftriaxone. Case reports in neonates show that administering intravenous ceftriaxone and calcium can result in precipitation of a ceftriaxone-calcium salt in the lungs and kidneys. In several cases, neonates have died as a result of this interaction (15794,21632). So far there are no reports in adults; however, there is still concern that this interaction might occur in adults.

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Using intravenous calcium with digoxin might increase the risk of fatal cardiac arrhythmias.  Details Hypercalcemia increases the risk of fatal cardiac arrhythmias with digoxin (12940). However, one retrospective analysis of clinical data suggests that intravenous calcium does not increase the risk of dysrhythmias or mortality in patients receiving digoxin (38960).

DILTIAZEM (Cardizem, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, calcium may reduce the therapeutic effects of diltiazem.  Details Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation (10574). Theoretically, calcium might increase this risk of hypercalcemia and reduce the effectiveness of diltiazem.

DOLUTEGRAVIR (Tivicay) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce levels of dolutegravir.  Details Advise patients to take dolutegravir either 2 hours before or 6 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium carbonate 1200 mg concomitantly with dolutegravir 50 mg reduces plasma levels of dolutegravir by almost 40%. Calcium appears to decrease levels of dolutegravir through chelation (93578).

ELVITEGRAVIR (Vitekta) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce levels of elvitegravir.  Details Advise patients to take elvitegravir either 2 hours before or 2 hours after taking calcium supplements. Pharmacokinetic research suggests that taking calcium along with elvitegravir can reduce blood levels of elvitegravir through chelation (94166).

LEVOTHYROXINE (Synthroid, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce the absorption and effectiveness of levothyroxine.  Details Advise patients to take levothyroxine and calcium supplements at least 4 hours apart. Calcium reduces levothyroxine absorption, probably by forming insoluble complexes (5082). Calcium carbonate supplements reduce effectiveness of levothyroxine in patients with hypothyroidism (5081,5082,6137).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use of calcium and lithium may increase this risk of hypercalcemia.  Details Clinical research suggests that long-term use of lithium may cause hypercalcemia in 10% to 60% of patients (38953). Theoretically, concomitant use of lithium and calcium supplements may further increase this risk.

QUINOLONE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Calcium seems to reduce the absorption of quinolone antibiotics.  Details Advise patients to take oral quinolones at least 2 hours before or 4-6 hours after calcium supplements or calcium-fortified foods. Taking calcium at the same time as oral quinolones can reduce quinolone absorption. Calcium binds to quinolones in the gut (4412,10339,21638,38570).

RALTEGRAVIR (Isentress) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Calcium may reduce levels of raltegravir.  Details Pharmacokinetic research shows that taking a single dose of calcium carbonate 3000 mg along with raltegravir 400 mg twice daily modestly decreases the mean area under the curve of raltegravir, but the decrease does not necessitate a dose adjustment of raltegravir (94164). However, a case of elevated HIV-1 RNA levels and documented resistance to raltegravir has been reported for a patient taking calcium carbonate 1 gram three times daily plus vitamin D3 (cholecalciferol) 400 IU three times daily in combination with raltegravir 400 mg twice daily for 11 months. It is thought that calcium reduced raltegravir levels by chelation, leading to treatment failure (94165).

SOTALOL (Betapace) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Calcium seems to reduce the absorption of sotalol.  Details Advise patients to separate doses by at least 2 hours before or 4-6 hours after calcium. Calcium appears to reduce the absorption of sotalol, probably by forming insoluble complexes (10018).

TETRACYCLINE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Calcium seems to reduce the absorption of tetracycline antibiotics.  Details Advise patients to take oral tetracyclines at least 2 hours before, or 4-6 hours after calcium supplements. Taking calcium at the same time as oral tetracyclines can reduce tetracycline absorption. Calcium binds to tetracyclines in the gut (1843).

THIAZIDE DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Taking calcium along with thiazides might increase the risk of hypercalcemia and renal failure.  Details Thiazides reduce calcium excretion by the kidneys (1902). Using thiazides along with moderately large amounts of calcium carbonate increases the risk of milk-alkali syndrome (hypercalcemia, metabolic alkalosis, renal failure). Patients may need to have their serum calcium levels and/or parathyroid function monitored regularly.

VERAPAMIL (Calan, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, calcium may reduce the therapeutic effects of verapamil.  Details Hypercalcemia can reduce the effectiveness of verapamil in atrial fibrillation (10574). Theoretically, use of calcium supplements may increase this risk of hypercalcemia and reduce the effectiveness of verapamil.

(Read more about CALCIUM)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking damiana with antidiabetes drugs might increase the risk of hypoglycemia.  Details Animal research shows that taking damiana lowers blood glucose level (4,25016).

(Read more about DAMIANA)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, eleuthero may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.  Details In vitro and animal research shows that a constituent of eleuthero, dihydroxybenzoic acid, appears to inhibit platelet aggregation (7592,74976). Concomitant use with anticoagulant or antiplatelet drugs might increase the risk of bleeding. This effect has not been reported in humans.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, eleuthero might have additive effects when used with antidiabetes drugs.  Details Animal research suggests that certain constituents of eleuthero have hypoglycemic activity in both healthy and diabetic animals (7591,73535,74932,74956,74988,74990). A small study in adults with type 2 diabetes also shows that taking eleuthero for 3 months can lower blood glucose levels (91509). However, one very small study in healthy individuals shows that taking powdered eleuthero 3 grams, 40 minutes prior to a 75-gram oral glucose tolerance test, significantly increases postprandial blood glucose levels when compared with placebo (12536). These contradictory findings might be due to patient-specific variability and variability in active ingredient ratios.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, eleuthero might increase levels of drugs metabolized by CYP1A2.  Details In vitro and animal research suggest that standardized extracts of eleuthero inhibit CYP1A2 (7532). This effect has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, eleuthero might increase levels of drugs metabolized by CYP2C9.  Details In vitro and animal research suggest that standardized extracts of eleuthero might inhibit CYP2C9 (7532). This effect has not been reported in humans.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, eleuthero might increase levels of drugs metabolized by CYP2D6.  Details In vitro and animal research suggest that standardized extracts of eleuthero might inhibit CYP2D6. However, research in healthy human volunteers has found that taking eleuthero 485 mg twice daily for 14 days does not inhibit CYP2D6 drug metabolism (7532,10400).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, eleuthero might increase levels of drugs metabolized by CYP3A4.  Details In vitro and animal research suggest that standardized extracts of eleuthero might inhibit CYP3A4. However, research in healthy human volunteers has found that taking eleuthero 485 mg twice daily for 14 days does not inhibit CYP3A4 drug metabolism (7532,10400).

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Unlikely •  Level of Evidence = D Eleuthero might increase serum digoxin levels and increase the risk of side effects.  Details In one case report, a 74-year-old male who was stabilized on digoxin presented with an elevated serum digoxin level after starting an eleuthero supplement, without symptoms of toxicity. After stopping the supplement, serum digoxin levels returned to normal (543). It is not clear whether this was due to a pharmacokinetic interaction or to interference with the digoxin assay (15585). Although the product was found to be free of digoxin and digitoxin (543), it was not tested for other contaminants (797).

IMMUNOSUPPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, eleuthero might interfere with immunosuppressive drugs because of its immunostimulant activity.  Details Animal and in vitro research shows that eleuthero extracts have immunomodulatory effects, including increasing cellular and humoral activity (74887,74915).

ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, eleuthero might decrease levels of drugs metabolized by OATP.  Details In vitro research suggests that eleuthero inhibits OATP2B1, which might reduce the bioavailability of oral drugs that are substrates of OATP2B1 (35450). Due to the weak inhibitory effect identified in this study, this interaction is not likely to be clinically significant.

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, eleuthero might increase levels of P-glycoprotein substrates.  Details In vitro research suggests that eleuthero can inhibit the multi-drug transporter protein, P-glycoprotein (22639,91509). However, it is too soon to tell if this is clinically important. This interaction has not been reported in humans.

(Read more about ELEUTHERO)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, horny goat weed might increase the risk of bleeding.  Details In vitro research and animal research shows that horny goat weed can inhibit platelet aggregation and thrombus formation (105832). This effect has not been reported in humans.

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, horny goat weed might increase the risk of hypotension.  Details Laboratory research suggests that horny goat weed might have hypotensive effects (10346). This effect has not been reported in humans.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, horny goat weed might increase the effects and side effects of CYP1A2 substrates.  Details In vitro, horny goat weed leaf extract inhibits CYP1A2 (97267). This effect has not been reported in humans.

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, horny goat weed might increase the effects and side effects of CYP2B6 substrates.  Details In vitro, horny goat weed leaf extract inhibits CYP2B6 (97267). This effect has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, horny goat weed might increase the effects and side effects of CYP3A4 substrates.  Details In vitro, horny goat weed extract inhibits CYP3A4 and suppresses CYP3A4 mRNA expression (112708). This effect has not been reported in humans.

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of horny goat weed with estrogens might increase their therapeutic and adverse effects.  Details In vitro evidence suggests that horny goat weed has estrogenic activity. In clinical research, horny goat weed has been shown to increase blood levels of estrogen in some females (16061,16063,16060,55452).

(Read more about HORNY GOAT WEED)

ACE INHIBITORS (ACEIs) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concomitant use of L-arginine and ACE inhibitors may increase the risk for hypotension and hyperkalemia.  Details Combining L-arginine with some antihypertensive drugs, especially ACE inhibitors, seems to have additive vasodilating and blood pressure-lowering effects (7822,20192,31854,31916). Furthermore, ACE inhibitors can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients (32213,32218). Theoretically, concomitant use of ACE inhibitors with L-arginine may increases the risk of hyperkalemia.

ANGIOTENSIN RECEPTOR BLOCKERS (ARBs) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concomitant use of L-arginine and ARBs may increase the risk of hypotension and hyperkalemia.  Details L-arginine increases nitric oxide, which causes vasodilation (7822). Combining L-arginine with ARBs seems to increase L-arginine-induced vasodilation (31854). Furthermore, ARBs can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients (32213,32218). Theoretically, concomitant use of ARBs with L-arginine may increases the risk of hyperkalemia.

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of L-arginine with anticoagulant and antiplatelet drugs might have additive effects and increase the risk of bleeding.  Details Preliminary research suggests that L-arginine infusions reduce platelet aggregation in humans (32260,31864,32239,32220,32257,32263,32276,32188). The clinical significance of this effect is unclear.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of L-arginine might have additive effects with antidiabetes drugs.  Details Preliminary clinical research shows that L-arginine decreases blood glucose levels in patients with type 2 diabetes (31964,32085,31964,104225).

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concomitant use of L-arginine and antihypertensive drugs may increase the risk of hypotension.  Details L-arginine increases nitric oxide, which causes vasodilation (7822). Clinical evidence shows that L-arginine can reduce blood pressure in some individuals with hypertension (7818,10636,31871,32201,32167,32225,31923,32232,110383,110384). Furthermore, combining L-arginine with some antihypertensive drugs seems to have additive vasodilating and blood pressure-lowering effects (7822,20192,31854,31916).

ISOPROTERENOL (Isuprel) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, concurrent use of isoproterenol and L-arginine might result in additive effects and hypotension.  Details Preliminary clinical evidence suggests that L-arginine enhances isoproterenol-induced vasodilation in patients with essential hypertension or a family history of essential hypertension (31932).

POTASSIUM-SPARING DIURETICS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically concomitant use of potassium-sparing diuretics with L-arginine may increases the risk of hyperkalemia.  Details Potassium-sparing diuretics can increase potassium levels. Use of L-arginine has been associated with hyperkalemia in some patients (32213,32218).

SILDENAFIL (Viagra) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concurrent use of sildenafil and L-arginine might increase the risk for hypotension.  Details In vivo, concurrent use of L-arginine and sildenafil has resulted in increased vasodilation (7822,8015,10636). Theoretically, concurrent use might have additive vasodilatory and hypotensive effects. However, in studies evaluating the combined use of L-arginine and sildenafil for erectile dysfunction, hypotension was not reported (105065).

TESTOSTERONE Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of L-arginine and testosterone might have additive effects.  Details In clinical research, L-arginine increases the level of testosterone in male patients with erectile dysfunction (102586,104222). The clinical significance of this finding is unclear.

(Read more about L-ARGININE)

(Read more about MUIRA PUAMA)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Taking tribulus with antidiabetes drugs might increase the risk of hypoglycemia.  Details Clinical research shows that Tribulus can lower blood glucose levels in adults with type 2 diabetes who are taking antidiabetes medications (97327).

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking tribulus with antihypertensive drugs might increase the risk of hypotension.  Details Animal research shows that tribulus can lower blood pressure by inhibiting angiotensin-converting enzyme (ACE) (12673). Tribulus has also demonstrated hypotensive effects in pre-hypertensive adults (105245).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, tribulus might increase the levels and clinical effects of lithium.  Details Tribulus is thought to have diuretic properties (12681). Due to these potential diuretic effects, tribulus might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

(Read more about TRIBULUS)

General ...Orally and intravenously, calcium is well-tolerated when used appropriately.
Most Common Adverse Effects:
Orally: Belching, constipation, diarrhea, flatulence, and stomach upset.
Serious Adverse Effects (Rare):
Orally: Case reports have raised concerns about calciphylaxis and kidney stones.

Cardiovascular ...There has been concern that calcium intake may be associated with an increased risk of cardiovascular disease (CVD) and coronary heart disease (CHD), including myocardial infarction (MI). Some clinical research suggests that calcium intake, often in amounts over the recommended daily intake level of 1000-1300 mg daily for adults, is associated with an increased risk of CVD, CHD, and MI (16118,17482,91350,107233). However, these results, particularly meta-analyses, have been criticized for excluding trials in which calcium was administered with vitamin D (94137). Many of these trials also only included postmenopausal females. Other analyses report conflicting results, and have not shown that calcium intake affects the risk of CVD, CHD, or MI (92994,93533,97308,107231). Reasons for these discrepancies are not entirely clear. It may relate to whether calcium is taken as monotherapy or in combination with vitamin D. When taken with vitamin D, which is commonly recommended, calcium supplementation does not appear to be associated with an increased risk of CVD, CHD, or MI (93533,107231). Also, the association between calcium supplementation and CVD, CHD, or MI risk may be influenced by the amount of calcium consumed as part of the diet. Supplementation with calcium may be associated with an increased risk of MI in people with dietary calcium intake above 805 mg daily, but not in those with dietary calcium intake below 805 mg daily (17482). To minimize the possible risk of CVD, CHD, or MI, advise patients not to consume more than the recommended daily intake of 1000-1200 mg and to consider total calcium intake from both dietary and supplemental sources (17484). While dietary intake of calcium is preferred over supplemental intake, advise patients who require calcium supplements to take calcium along with vitamin D, as this combination does not appear to be associated with an increased risk of MI (93533).
Rarely, calcium intake can increase the risk of calciphylaxis, which usually occurs in patients with kidney failure. Calciphylaxis is the deposition of calcium phosphate in arterioles, which causes skin ulcers and skin necrosis. In a case report, a 64-year-old female with a history of neck fracture, sepsis, and ischemic colitis presented with painful leg ulcers due to calciphylaxis. She discontinued calcium and vitamin D supplementation and was treated with sodium thiosulfate and supportive care (95816).

Gastrointestinal ...Orally, calcium can cause belching, flatulence, nausea, gastrointestinal discomfort, and diarrhea (1824,1843,12950,38803). Although constipation is frequently cited as an adverse effect of calcium, there is no scientific substantiation of this side effect (1824,1843,1844,1845,12950,38978). Calcium carbonate has been reported to cause acid rebound, but this is controversial (12935,12936).

Oncologic ...There is some concern that very high doses of calcium might increase the risk of prostate cancer. Some epidemiological evidence suggests that consuming over 2000 mg/day of dietary calcium might increase the risk for prostate cancer (4825,12949). Additional research suggests that calcium intake over 1500 mg/day might increase the risk of advanced prostate cancer and prostate cancer mortality (14132). Consumption of dairy products has also been weakly linked to a small increase in prostate cancer risk (98894). However, contradictory research suggests no association between dietary intake of calcium and overall prostate cancer risk (14131,14132,104630). More evidence is needed to determine the effect of calcium, if any, on prostate cancer risk.

Renal ...Kidney stones have been reported in individuals taking calcium carbonate 1500 mg daily in combination with vitamin D 2000 IU daily for 4 years (93943).

(Read more about CALCIUM)

General ...Orally, adverse effects to damiana seem to be rare; however, a thorough safety evaluation has not been conducted.

Neurologic/CNS ...Orally, 200 grams of damiana extract has caused tetanus-like convulsions and paroxysms resulting in symptoms similar to rabies or strychnine poisoning (4).

(Read more about DAMIANA)

General ...Orally, eleuthero root is generally well tolerated when used short-term.
Most Common Adverse Effects:
Orally: Diarrhea, dyspepsia, gastrointestinal upset, headache, nausea, and urticaria.

Cardiovascular ...Orally, increased blood pressure has been reported in children with hypotension taking eleuthero in one clinical study (74980). Eleuthero has been reported to cause tachycardia, hypertension, and pericardial pain in patients with rheumatic heart disease or atherosclerosis. It is unclear if these effects were caused by eleuthero, or by the cardioglycoside-containing herb, silk vine (Periploca sepium), which is a common adulterant found in eleuthero products (12,797,6500).

Dermatologic ...Orally, eleuthero has been reported to cause rash in some clinical studies (75013,75028).

Gastrointestinal ...Orally, eleuthero has been reported to cause dyspepsia, nausea, diarrhea, and gastrointestinal upset in some patients (74938,75028,91510).

Genitourinary ...Orally, mastalgia and uterine bleeding were reported in 7. 3% of females taking eleuthero 2 grams daily in one clinical study (6500,11099). These adverse effects seem to be more likely with higher doses.

Neurologic/CNS ...Orally, headaches have been reported in 9. 8% of people taking eleuthero in one clinical study (11099).
In one case report, a 53-year-old female developed spontaneous subarachnoid hemorrhage associated with the use of an herbal supplement containing red clover, dong quai, and eleuthero (70419). It is unclear if this event was related to the use of eleuthero, the other ingredients, the combination, or another cause entirely.

Psychiatric ...Orally, nervousness has been reported in 7. 3% of people taking eleuthero in one clinical study (11099). Eleuthero has also been reported to cause slight anxiety, irritability, and melancholy in some patients (6500,11099). These adverse effects seem to be more likely to occur with higher doses.

(Read more about ELEUTHERO)

General ...Orally, horny goat weed seems to be well tolerated when used short-term.
Most Common Adverse Effects:
Orally: Dizziness, dry mouth, nosebleed, thirst, and vomiting.
Serious Adverse Effects (Rare):
Orally: Respiratory arrest.

Cardiovascular ...A 66-year-old male with a history of cardiovascular disease developed tachyarrhythmia after taking horny goat weed for 2 weeks (13006). It is not clear if this product contained only horny goat weed or a combination of ingredients; therefore, assigning causality is not possible.

Gastrointestinal ...Orally, long-term use of horny goat weed has been associated with reports of vomiting, dry mouth, thirst, and nosebleed (10346).

Hepatic ...A case of hepatotoxicity characterized by abdominal pain, nausea, vomiting, and fever has been reported in a 40-year-old male patient with hepatitis C, after a month of taking one tablet daily of a combination product containing horny goat weed and multiple other ingredients (Enzyte, Vianda). Symptoms improved following cessation of the product, but it is not clear if they were due to horny goat weed, another ingredients, or hepatitis C (91590). An observational study over 24 years found 26 cases of drug-induced hepatoxicity associated with horny goat weed (112707).

Musculoskeletal ...Orally, large doses of horny goat weed may cause exaggeration of tendon reflexes to the point of spasm (10346).

Neurologic/CNS ...Orally, long-term use of horny goat weed has been associated with reports of dizziness (10346).

Psychiatric ...There is a case report of hypomania in a 66-year-old male who took horny goat weed for 2 weeks (13006). It is not clear if this product contained only horny goat weed or a combination of ingredients; therefore, assigning causality is not possible.

Pulmonary/Respiratory ...Orally, large doses of horny goat weed may cause respiratory arrest (10346).

(Read more about HORNY GOAT WEED)

General ...Oral, intravenous, and topical L-arginine are generally well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, bloating, nausea, diarrhea, headache, insomnia, flushing.
Intravenously: Excessively rapid infusion can cause flushing, headache, nausea and vomiting, numbness, and venous irritation.

Cardiovascular ...L-arginine taken orally by pregnant patients in a nutrition bar containing other antioxidants was associated with a 36% greater risk of palpitations when compared with a placebo bar (91197). It is unclear if this effect was due to L-arginine, other ingredients, or other factors.

Dermatologic ...Orally, arginine can cause flushing, rash, and hives (3460,32138,102587,104223). The skin reactions were likely of allergic etiology as oral L-arginine has been associated with eosinophilia (32138). In one case report, intravenous administration caused allergic reactions including urticaria, periorbital edema, and pruritus (11830). Excessively rapid infusion of L-arginine has caused flushing, local venous irritation, numbness. Extravasation has caused necrosis and superficial phlebitis (3330,16817).

Gastrointestinal ...Orally, L-arginine has been reported to cause nausea, diarrhea, vomiting, dyspepsia, gastrointestinal discomfort, and bloating (1363,31855,31871,31972,31978,32261,90198,91197,96811,99243)(102587,102592).
Orally, L-arginine has been reported to cause esophagitis in at least six adolescents. Symptoms, which included pain and dysphagia, occurred within 1-3 months of treatment in most cases (102588). There are at least two cases of acute pancreatitis possibly associated with oral L-arginine. In one case, a 28-year-old male developed pancreatitis after consuming a shake containing 1.2 grams of L-arginine daily as arginine alpha-ketoglutarate. The shake also contained plant extracts, caffeine, vitamins, and other amino acids. Although there is a known relationship between L-arginine and pancreatitis in animal models, it is not clear if L-arginine was directly responsible for the occurrence of pancreatitis in this case (99266).
Intravenously, excessively rapid infusion of L-arginine has been reported to cause nausea and vomiting (3330,16817).

Musculoskeletal ...Intravenous L-arginine has been associated with lower back pain and leg restlessness (32273). Orally, L-arginine has been associated with asthenia (32138).

Neurologic/CNS ...Orally, L-arginine has been associated with headache (31855,31955,32261,91197,102587,102592), insomnia, fatigue (102587,102592), and vertigo (32150,102592).

Oncologic ...In breast cancer patients, L-arginine stimulated tumor protein synthesis, which suggests stimulated tumor growth (31917).

Pulmonary/Respiratory ...When inhaled, L-arginine can cause airway inflammation and exacerbation of airway inflammation in asthma (121). However, two studies assessing oral L-arginine in patients with asthma did not detect any adverse airway effects (31849,104223).

Renal ...Intravenously, L-arginine has been associated with natriuresis, kaliuresis, chloruresis, and systemic acidosis (32225). Orally, L-arginine can cause gout (3331,3595).

Other ...Orally, L-arginine has been associated with delayed menses, night sweats, and flushing (31855).

(Read more about L-ARGININE)

General ...No adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.

(Read more about MUIRA PUAMA)

General ...Orally, tribulus seems to be well tolerated.
Serious Adverse Effects (Rare):
Orally: Cases of liver and kidney injury, seizures, and chronic painful erection with impaired sexual function have been reported. Pneumothorax and bronchial polyp after consuming the spine-covered tribulus fruit have been reported.

Gastrointestinal ...Orally, tribulus can cause abdominal pain, cramping, nausea, vomiting, diarrhea, and constipation (92022,92027). However, in one study, the rates of these gastrointestinal complaints were similar for patients taking tribulus and those receiving placebo (92022).

Genitourinary ...In one case report, a patient taking two tribulus tablets (unknown dose) daily for 15 days presented to the local emergency department with a painful erection lasting 72 hours. The priapism was resolved with medical management; however, post-episode sexual function was impaired (92023).

Hepatic ...In one case report, a patient drinking tribulus water 2 liters daily for two days presented with lower limb weakness, seizures, hepatitis, and acute kidney injury. The patient's condition improved after hemodialysis and discontinuation of tribulus water (92069).

Neurologic/CNS ...Orally, tribulus has been reported to cause general excitation and insomnia. These symptoms were reversed upon discontinuation of the drug or decreasing the dose (78867). In one case report, a patient drinking tribulus water 2 liters daily for two days presented with lower limb weakness, seizures, hepatitis, and acute kidney injury. The patient's condition improved after hemodialysis and discontinuation of tribulus water (92069).

Pulmonary/Respiratory ...In one case report, a patient developed a bilateral pneumothorax after consuming the spine-covered fruit of tribulus (818). In another case report, a patient developed a polyp in the lobar bronchus of the right interior lobe due to the presence of a tribulus fruit spine (78852).

Renal ...In one case report, a patient drinking tribulus water 2 liters daily for two days presented with lower limb weakness, seizures, hepatitis, and acute kidney injury. The patient's condition improved after hemodialysis and discontinuation of the tribulus water (92069). In another case report, a healthy male taking one tribulus tablet (unknown dose) daily for a few months for bodybuilding purposes developed hyperbilirubinemia followed by acute kidney failure 2-3 weeks later. The patient was managed with intravenous fluids and a low-salt, low-protein diet (92025).

Other ...In one case report, gynecomastia was observed in a male weightlifter taking an herbal combination product containing tribulus. However, it is not clear if this adverse effect can be attributed to tribulus alone (78859).

(Read more about TRIBULUS)