Basic Pygeum Herbal by Thorne Research

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Benign prostatic hyperplasia (BPH). Although there has been interest in using oral alanine for BPH, there is insufficient reliable information about the clinical effects of alanine for this purpose.
• Diabetes. Although there has been interest in using oral alanine for diabetes, there is insufficient reliable information about the clinical effects of alanine for this purpose.
• Diarrhea-related dehydration. It is unclear if oral alanine is beneficial in children or adults with diarrhea-related dehydration. Details: One preliminary clinical trial in males age 6-59 years with severe secretory diarrhea primarily related to cholera or enterotoxigenic Escherichia coli shows that an oral rehydration solution fortified with L-alpha-alanine 90 mmol/L, along with a reduced glucose concentration, is significantly more effective for reducing stool output than the standard WHO solution (16028). However, other clinical research in males age 3-48 months of age with diarrhea primarily related to viral infections shows that an oral rehydration solution fortified with L-alpha-alanine 30-90 mmol/L along with a reduced glucose concentration is not significantly more effective at reducing stool output than the standard WHO oral rehydration solution (16021).
• Fatigue. Although there has been interest in using oral alanine for fatigue, there is insufficient reliable information about the clinical effects of alanine for this purpose.
• Glycogen storage disease type II (Pompe disease). It is unclear if oral alanine is beneficial in patients with Pompe disease. Details: A case series of 5 patients aged 15-47 years with late-onset glycogen storage disease type II shows that taking L-alpha-alanine 0.14 grams/kg daily, divided into 3 doses, for 4 weeks decreased resting energy expenditure, protein turnover, and catabolism when compared with baseline. However, measures of Pompe disease-associated myopathy were not reported. The validity of this study is limited by its small size and the lack of a comparator group (16444).
• Hypoglycemia. Small clinical studies suggest that oral alanine may modestly reduce iatrogenic hypoglycemia in patients with type 1 diabetes. Details: Preliminary clinical research shows that taking 20-40 grams of L-alpha-alanine orally produces a sustained rise in blood glucose levels after insulin-induced hypoglycemia in people with type 1 diabetes (14612,16020). The rise is more prolonged than after 20 grams of oral glucose or 1 mg of subcutaneous glucagon (14612). Other preliminary clinical research also shows that patients with type 1 diabetes had more consistent and prolonged protection against nocturnal hypoglycemia after taking 40 grams of L-alpha-alanine plus 10 grams of glucose orally with a bedtime dose of NPH insulin than when they consumed a snack with the insulin dose (16019).
• Schizophrenia. It is unclear if oral alanine is beneficial in patients with schizophrenia. Details: Preliminary clinical research shows that taking D-alpha-alanine orally 100 mg/kg daily for 6 weeks improves positive and negative symptom scores in patients with schizophrenia that were also on a stable antipsychotic regimen when compared with placebo (16027).
• Stress. Although there has been interest in using oral alanine for stress, there is insufficient reliable information about the clinical effects of alanine for this purpose. More evidence is needed to rate alanine for these uses.

(Read more about ALANINE)

EFFECTIVE

• Sickle cell disease. A specific oral glutamine powder (Endari, Emmaus Medical, Inc) is approved by the US Food and Drug Administration (FDA) to reduce acute complications of sickle cell disease. Details: Clinical research in adults and children 5 years of age and older shows that taking glutamine 5-15 grams (0.3 grams/kg body weight) orally twice daily for 48 weeks, either with or without hydroxyurea, delays the median time to first crisis by 30 days, and reduces the incidence of acute chest syndrome by 15%, number of hospitalizations by 33%, and the number of hospitalized days by 40%, when compared with placebo (96519,99414).

POSSIBLY EFFECTIVE

• Burns. Oral glutamine seems to improve healing in patients with severe burns and may also reduce the risk for burn wound infections; however, it is unclear if glutamine improves hospitalization length or mortality. Details: Some clinical research shows that administering enteral nutrition supplemented with glutamine 0.35-0.5 grams/kg daily for 12-14 days, beginning within 24-48 hours of hospitalization for severe burn injury (excluding inhalation injury), decreases the length of hospital stay by 6-9 days and may shorten wound healing when compared to control enteral nutrition (52307,52337). A clinical study in adults with moderate to severe burns (including inhalation injury) shows that administering enteral nutrition supplemented with intravenous alanyl glutamine 0.5 grams/kg daily, beginning within 24 hours of burn injury and continued for 14 days, may improve burn-induced organ damage, particularly intestinal mucosal injury, but does not improve mortality or length of hospitalization, when compared with standard nutritional support (108027). Another study in the same population shows that administering enteral nutrition supplemented with glutamine 4.3 grams every 4 hours, beginning within 24 hours of burn injury, decreases the risk of mortality by 83% and the risk of Pseudomonas wound infections; however, it does not decrease the duration of hospitalization (52311). A meta-analysis of these trials and one additional trial shows that administering glutamine enterally reduces the risk of Gram-negative bacterial wound infections by 73% and reduces the risk of mortality by 87% when compared to a control group. However, there was no difference in length of stay or overall wound infection rate (97363). Results were based on a small number of patients within each outcome evaluation. Intravenous glutamine has also been evaluated. One small clinical study shows that intravenous glutamine 0.57 grams/kg daily decreases the incidence of Gram-negative bacteremia by 35% when compared with control in patients with severe burns. However, it does not appear to decrease the incidence of Gram-positive bacteremia, the need to use antibiotics, or risk of mortality (52272).
• Critical illness (trauma). Oral and intravenous glutamine seem to reduce infectious complications in critically ill adults. However, glutamine does not seem to reduce mortality in this population. Details: Some studies show that glutamine reduces the risk of infectious complications in critically ill, multiple-trauma, or postoperative adult patients (5449,5450,7309,7731,8184,52288,52359). However, other studies show no benefit (52308,52360,97362). Meta-analyses of these and other clinical trials suggest that glutamine supplementation reduces the risk of nosocomial infections in critically ill patients by 15% to 18% and the risk of nosocomial infections in surgical patients by 30% to 41%. This benefit was seen only with parenteral glutamine; enteral glutamine does not appear to reduce the risk for nosocomial infection (91355,91358). The role of glutamine for reducing mortality in critically ill adults is conflicting. Some clinical trials suggest that glutamine-enriched enteral and parenteral nutrition reduces mortality in critically ill patients (52283,52289,52408). However, other studies show no benefit (52288,52308,52354,52359,97362). Meta-analyses of results from these and other clinical trials show that, overall, taking glutamine does not reduce the risk of mortality in critically ill patients (91355,91358). However, the dose and dosage form may affect outcomes. One meta-analysis shows that glutamine does not affect the risk of mortality when administered at doses up to 0.5 grams/kg daily, although doses greater than 0.5 grams/kg daily may INCREASE mortality by 18% (91355). Another meta-analysis shows that glutamine decreases short-term mortality in critically ill patients by 25% when administered parenterally, but not enterally (91358). Neither parenteral nor enteral glutamine appears to decrease the risk of long-term mortality in critically ill patients (91358). Research evaluating glutamine in critically ill children is limited. One clinical study in children ages 1-17 admitted to an intensive care unit (ICU) shows that enteral administration of glutamine along with zinc, selenium, and intravenous metoclopramide does not reduce nosocomial infections when compared with whey supplementation (86095).
• HIV/AIDS-related wasting. Oral glutamine seems to attenuate weight loss related to HIV/AIDS. Details: Very small clinical studies show that taking glutamine orally seems to enhance intestinal absorption of nutrients, decrease intestinal permeability, and increase weight gain in adults with HIV/AIDS when compared with placebo. Doses of 40 grams daily seem to produce the greatest effect (2337,2702). Lower doses of 14 grams daily might also be effective when used in combination with arginine and hydroxymethylbutyrate (a leucine metabolite) (7310).
• Postoperative recovery. Oral or intravenous glutamine seems to reduce the duration of hospitalization and improve postoperative nutritional status in adults. However, it does not seem to reduce postoperative mortality. Details: Although some conflicting evidence exists (52316), most clinical research shows that receiving free glutamine or glutamine-containing dipeptide intravenously decreases the duration of hospitalization after surgery, particularly after major abdominal surgery (2363,5448,7300,7732,52275,52341). A meta-analysis of this research and other studies shows that IV supplementation with glutamine-containing dipeptides reduces the length of hospital stay by 3 days when compared with no supplementation (96507). Other meta-analyses of clinical research also show that glutamine supplementation, as free glutamine or glutamine-containing dipeptides, reduces the risk of hospital-acquired infections by 30% in surgical intensive care unit (ICU) patients and by 41% in elective surgical patients (91355,91358). In cancer patients undergoing abdominal surgery, glutamine-supplemented parenteral nutrition seems to improve nutritional status and gastrointestinal function (100943). Glutamine-containing dipeptides also appear to help to preserve intestinal integrity (7299,7300,7732,52306). One small study has evaluated oral glutamine 10 grams, in combination with arginine 4.5 grams, in patients undergoing surgery for enterocutaneous fistulas. This study shows that taking this combination daily for 7 days prior to surgery reduces recurrence of fistulas by 35%, and also reduces postoperative infections (103837). Although glutamine seems to decrease length of stay and reduce infection rate, it does not appear to reduce the risk of mortality in either surgical ICU or elective surgical patients (91355,91358,96509,103834), including those receiving major abdominal surgery (5448,52316,91355,96507). Additionally, most research shows that glutamine supplementation does not reduce the incidence of infectious complications following abdominal surgery (52306,52316,52341,5448,7300,96507). The effects of glutamine on reducing infection rate might be related to patient population, modes of nutrition, or dose of glutamine. Taking a combination of glutamine 7 grams, arginine 7 grams, and hydroxymethylbutyrate 1.2 grams (Abound, Abbott) orally daily for 3 days before and 7 days after abdominal surgery does not reduce the incidence of wound infections or other complications (99413). Most of the research evaluating glutamine in surgical patients has been conducted in adults. Information in children is limited. Existing clinical research shows that glutamine-fortified parenteral nutrition does not improve intestinal permeability, nitrogen balance, duration of hospitalization, incidence of infectious complications, or risk of mortality in newborns and infants undergoing digestive-tract surgery (52338,96508).

POSSIBLY INEFFECTIVE

• Athletic performance. Oral glutamine does not seem to improve athletic performance. Details: Small studies in trained athletes or healthy adults show that taking glutamine orally does not seem to enhance performance or immune response during intense acute or prolonged exercise when compared with placebo (2341,2342,5455,5456).
• Crohn disease. Oral glutamine does not seem to improve symptoms of this condition. Details: Small clinical studies in adults and children with Crohn disease show that taking glutamine 7 grams three times daily or following a glutamine-enriched diet for 4 weeks does not seem to improve intestinal permeability or disease activity, and might even worsen disease activity, when compared with placebo or a low-glutamine diet (2338,6256).
• Cystinuria. Oral glutamine does not seem to improve cystinuria. Details: According to case reports, taking glutamine orally does not seem to reduce the excretion of cysteine in the urine in patients with homozygous cystinuria (2339).
• Low birth weight. Oral glutamine does not seem to reduce adverse consequences of low birth weight in infants. Details: Most clinical studies show that glutamine supplementation does not improve the time to full enteral feeding, infant growth rate, or length of hospital stay in low birth weight infants (52305,52312,52325,52342,52362,52410). One follow-up study also shows that neonatal glutamine supplementation is not associated with improvements in cognitive function, motor skills, or behavior outcomes by school age when corrected for neonatal infection rate (52342,97365).
• Muscular dystrophy. Oral glutamine does not seem to improve symptoms of Duchenne muscular dystrophy. Details: Clinical studies show that taking glutamine 0.5-0.6 grams/kg orally does not significantly improve muscle strength or whole body protein degradation in children with Duchenne muscular dystrophy when compared with placebo or a nonspecific amino acid mixture (46657,52363).
• Prematurity. Oral glutamine does not seem to reduce morbidity or mortality associated with prematurity. Details: A meta-analysis of clinical trials in preterm infants, including infants with low to very low birth weight, shows that use of enteral or parenteral glutamine does not reduce the risk of mortality or morbidities, such as necrotizing enterocolitis, when compared with control. However, limited evidence from a sub-group analysis suggests that enteral glutamine might modestly reduce the risk of invasive infection when compared with control (105015). These findings are limited by the selection bias and heterogeneity of the included trials.
• Radiation-induced diarrhea. Oral glutamine does not seem to improve diarrhea due to radiation therapy. Details: One meta-analysis of five randomized, controlled trials shows that taking oral glutamine during radiotherapy for pelvic cancers does not prevent or reduce the severity of diarrhea when compared with placebo (97367).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Antiretroviral-associated diarrhea. It is unclear if oral glutamine improves diarrhea caused by antiretroviral agents. Details: A small crossover clinical study in HIV patients shows that oral glutamine 30 grams daily for 10 days seems to reduce the severity of nelfinavir-associated diarrhea when compared with placebo (52313).
• Alcohol use disorder. Although there is interest in using oral glutamine for alcohol use disorder, there is insufficient reliable information about the clinical effects of glutamine for this condition.
• Attention deficit-hyperactivity disorder (ADHD). Although there is interest in using oral glutamine for ADHD, there is insufficient reliable information about the clinical effects of glutamine for this condition.
• Chemotherapy-induced diarrhea. It is unclear if oral glutamine improves diarrhea caused by chemotherapy. Details: Although preliminary clinical studies show that glutamine might reduce the occurrence of chemotherapy-induced diarrhea (7235,7285), a meta-analysis of this research and others shows no difference in the severity of diarrhea (7233,7295,96516). Despite results showing a significant 1-day reduction in the duration of diarrhea, this might not be considered clinically significant (96516).
• Chemotherapy-induced lymphocytopenia. It is unclear if oral glutamine reduces lymphocytopenia caused by chemotherapy. Details: One small clinical study in patients with esophageal cancer receiving chemo-radiotherapy shows that taking glutamine 30 grams daily for 28 days seems to prevent a reduction in lymphocytes when compared with placebo (2705). However, another small clinical trial in patients with leukemia or lymphoma receiving intensive chemotherapy shows that adding glutamine 26 grams to total parenteral nutrition (TPN), in place of other amino acids, does not affect duration of neutropenia when compared with receiving an isonitrogenous standard TPN (7295).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral glutamine is beneficial in patients hospitalized with COVID-19 pneumonia. Details: A very small, nonblinded, non-randomized evaluation of otherwise healthy patients over 50 years of age who were hospitalized with mild COVID-19 pneumonia shows that taking glutamine 10 grams three times daily orally with meals is associated with a 1-day decrease in hospital stay (from 10 days to 9) when compared with patients not taking glutamine. In the latter group, 4 patients required transfer to the ICU, compared with no patients in the glutamine group (103839). A similar, non-randomized evaluation of adults hospitalized with COVID-19 pneumonia shows that adding the same dose of glutamine to other therapies for 5 days is associated with a 3-day decrease in hospital stay (from 14 days to 11) when compared with patients not taking glutamine. At the end of treatment, 0% of patients in the glutamine group required ICU services, compared with 54% of patients who did not receive glutamine. This study also shows that taking glutamine may increase appetite (108035). The validity of these findings is limited by short duration of treatment and use of non-standardized treatments.
• Cystic fibrosis. It is unclear if oral glutamine improves growth and development in children with cystic fibrosis. Details: A small clinical study in undernourished or stunted children with cystic fibrosis shows that taking glutamine 0.7 grams/kg daily orally for 4 weeks with or without recombinant human growth hormone (rhGH) does not promote protein gain when compared with rhGH alone (52321).
• Diabetic foot ulcers. Oral glutamine 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 nutritional supplement drink containing glutamine 7 grams, arginine 7 grams, and hydroxymethylbutyrate 1.5 grams (Abound, Abbott) twice daily for 16 weeks does not improve total wound closure or reduce the time to complete healing when compared with a control drink in patients with diabetic foot ulcers (96637). It is unclear if this effect is due to glutamine, other ingredients, or the combination.
• Diarrhea. It is unclear if oral glutamine improves diarrhea in children and infants. Details: One preliminary clinical study in 6-24 month-old otherwise healthy children with acute diarrhea shows that taking capsules prepared with a specific glutamine powder (Power Glutamine, Champion Nutrition) 0.3 grams/kg daily for 7 days reduces the duration of diarrhea by about one day when compared with placebo (52323). However, other clinical research in male infants 1-12 months old with acute diarrhea and dehydration shows that adding glutamine 90 mmol/L along with the standard World Health Organization oral rehydration salts (ORS) does not decrease the duration of diarrhea, stool output, or the volume of oral rehydration solution required to achieve and maintain hydration when compared with standard ORS alone (7298).
• Hematopoietic stem cell transplant (HSCT). It is unclear whether oral glutamine or glutamine added to parenteral nutrition improves morbidity and mortality in patients undergoing HSCT. Some research has suggested that intravenous glutamine may actually worsen outcomes. Details: Some research suggests that patients receiving glutamine-supplemented parenteral nutrition (PN) after HSCT primarily to treat hematologic malignancies have a diminished incidence of clinical infections, lower rates of microbial colonization, and decreased length of hospital stay when compared to control (2366,52381). However, not all patients seem to benefit. Some research shows that oral glutamine or PN with glutamine does not reduce the risk of mortality or infections in patients with hematologic malignancies and/or solid tumors (5451,52385). Also, a small clinical study in patients undergoing HSCT shows that PN with glutamine dipeptide may increase the duration of hospital stay (52292). Furthermore, one small study has found that receiving PN with glutamine was associated with lower disease-free survival and event-free survival over 3 years when compared with standard PN in patients receiving HSCT for hematologic malignancies (52355).
• Irritable bowel syndrome (IBS). There is limited evidence on the oral use of glutamine in patients with IBS. Details: A clinical trial in adults with IBS (diarrhea-predominant, constipation-predominant, mixed, or alternating bowel habits) shows that following a low FODMAP diet supplemented with oral glutamine 15 grams three times daily for 6 weeks improves IBS-Severity Scoring System (IBS-SSS) scores, with 88% of patients in the glutamine group reporting a 45% improvement in severity scores, compared with 60% of patients following the low FODMAP diet alone (108037). The validity of this finding is limited by short duration of treatment and lack of follow-up. Preliminary clinical research in patients with postinfectious, diarrhea-predominant IBS shows that taking glutamine 5 grams three times daily for 8 weeks leads to a nearly 14-fold greater likelihood of symptom improvement, defined as a reduction of 50 points or more on the IBS-SSS, and decreases stool frequency by 2.45 stools daily when compared with placebo. Taking glutamine also seems to reduce abdominal pain ratings by 55% and improve quality of life scores by 53% when compared to baseline in these patients (100944). The validity of these findings is limited by the lack of a comparator group.
• Lung cancer. It is unclear if oral glutamine improves survival in patients with advanced lung cancer. Details: One small clinical study in patients with advanced non-small cell lung cancer shows that taking glutamine 10 grams three times daily for 12 months along with palliative chemoradiotherapy prevents weight loss, which is an important predictor of survival, but does not increase the likelihood of progression-free survival when compared with palliative chemoradiotherapy alone (100942). It is unclear if this study was adequately powered to detect a difference in survival between groups.
• Malnutrition. It is unclear if oral alanyl-glutamine improves height and weight in children at risk for malnutrition. Details: Preliminary clinical research in children aged 2 months to 5 years from a low-income area of Brazil and at risk for malnutrition, shows that taking 3-12 grams of alanyl-glutamine orally daily for 10 days improves gut integrity and is associated with a modest, short-term increase in weight when compared with a glycine placebo (103838).
• Exercise-induced muscle damage. It is unclear if oral glutamine is beneficial for exercise-induced muscle damage. Details: A very small clinical crossover trial in professional athletes undergoing rigorous training shows that taking oral glutamine 6 grams daily for 20 days reduces serum levels of creatine kinase and myoglobin when compared with placebo (108031). The validity of these findings is limited due to the small size and short duration of treatment.
• Obesity. It is unclear if oral glutamine is beneficial for weight loss. Details: A preliminary clinical study in 36 overweight or obese adults shows that taking glutamine 30 grams daily for 2 weeks reduces waist circumference by 1.8 cm, but does not improve body weight, body mass index, or glycemic indices, when compared to baseline. None of these outcomes were improved over baseline in an alanine control group (100941). Given the small study size and short duration of therapy, the long-term effects of glutamine on anthropometric measures is unclear.
• Opioid withdrawal. Oral glutamine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in Chinese patients undergoing detoxification from heroin shows that taking a combination of tyrosine, lecithin, 5-HTP, and glutamine 50 mg/kg orally daily for 6 days might reduce mood-related withdrawal symptoms when compared with placebo (88178). It is unclear if this effect is due to glutamine, other ingredients, or the combination.
• Oral mucositis. There is contradictory evidence about the effects of glutamine in patients with, or at risk of developing, oral mucositis from chemotherapy or radiotherapy. Details: Small clinical studies suggest that taking glutamine orally or swishing and swallowing a glutamine solution can decrease the incidence, severity, and duration of oral mucositis in some patients undergoing chemotherapy and/or radiation therapy for cancer or hematopoietic stem cell transplant (HSCT) (2336,2368,2704,5029). Additionally, three meta-analyses of highly heterogeneous clinical trials in patients with cancer receiving chemotherapy and/or radiation therapy suggests that glutamine reduces the incidence of severe (grade ≥3) oral mucositis when compared with control (105014,108028,108036). These analyses are limited for several reasons, including reporting bias, lack of sensitivity analysis, and population heterogeneity. Some small clinical studies included in these meta-analyses suggest that supplementation with glutamine may reduce the need for feeding tubes and opioid analgesics (108028,108036). However, not all research has been positive. Some small clinical studies in patients receiving chemotherapy with 5-fluorouracil for cancer or HSCT suggest that oral or intravenous glutamine does not reduce the incidence of oral mucositis when compared with control (2365,5451,5462,7296,52349,52350). Furthermore, a meta-analysis of 5 clinical trials in patients with head or neck cancers shows that oral glutamine does not reduce the overall incidence or the incidence of moderate to severe radiation-induced oral mucositis when compared with control (103836). The Multinational Association of Supportive Care in Cancer and the International Society for Oral Oncology (MASCC/ISOO) cautiously recommends the use of oral glutamine to prevent oral mucositis in patients with head and neck cancer receiving chemoradiotherapy. However, due to some evidence suggesting that intravenous glutamine may actually worsen outcomes in HSCT patients, the MASCC/ISOO recommends against its use for the prevention of oral mucositis in patients receiving high-dose chemotherapy, with or without total body irradiation, for HSCT (105004).
• Paclitaxel-induced myalgia and arthralgia. It is unclear if oral glutamine reduces the risk for myalgias and arthralgias due to paclitaxel. Details: One small clinical study shows that taking glutamine 10 grams three times daily for 5 days, starting on the day of chemotherapy and repeated over 2 cycles of chemotherapy, does not reduce the rate or severity of paclitaxel-induced myalgias or arthralgias when compared with placebo (52331).
• Pancreatitis. It is unclear if oral glutamine improves outcomes in patients with acute pancreatitis. Details: Two meta-analyses of the available clinical research in patients with pancreatitis show that enteral or parenteral supplementation with glutamine increases albumin, decreases C-reactive protein, and might reduce mortality, multiple organ dysfunction syndrome, hospital length of stay, and infections. Results are difficult to interpret due to the significant heterogeneity of the included trials and limited generalizability of the results (96513,103835).
• Peptic ulcers. Although there is interest in using oral glutamine for peptic ulcers, there is insufficient reliable information about the clinical effects of glutamine for this condition.
• Postoperative infection. It is unclear if oral or intravenous glutamine is beneficial for the prevention of postoperative infection in patients with colorectal cancer who are recovering from surgery. Details: A meta-analysis of nonblinded clinical research in adults with colorectal or colon cancer who recently underwent radical surgery shows that daily supplementation with glutamine 0.3-1 grams/kg, administered either orally or parenterally, improves the rate of surgical site infections and anastomotic leakage when compared with control (108033). These findings are limited by the high heterogeneity of the included studies and unclear reporting.
• Postoperative recovery. It is unclear if oral or intravenous glutamine is beneficial in patients with colorectal cancer who are recovering from surgery. Details: A meta-analysis of nonblinded clinical research in adults with colorectal or colon cancer who recently underwent radical surgery shows that taking either oral or parenteral glutamine 0.3-1 grams/kg daily may reduce the length of hospital stay when compared with control (108033). These findings are limited by the high heterogeneity of the included studies and unclear reporting.
• Pressure ulcers. Oral glutamine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in patients with stages II-IV pressure ulcers shows that taking a specific nutritional supplement drink containing glutamine 7 grams, arginine 7 grams, and hydroxymethylbutyrate 1.5 grams per packet (Abound, Abbott Nutrition) as two packets twice daily by mouth for 2 weeks has no effect on wound area or healing scores by the Pressure Ulcer Scale for Healing (PUSH) measurement when compared with standard nutritional care (96506).
• Radiation dermatitis. It is unclear if oral glutamine reduces the risk of developing dermatitis from radiation therapy. Details: One small clinical study in patients with head and neck cancers receiving cisplatin shows that taking a specific supplement containing glutamine 7 grams, arginine 7 grams, and hydroxymethylbutyrate 1.5 grams (Abound, Abbott) orally twice daily, starting on day 1 of radiation and continuing until 1 week after radiation therapy, does not reduce the incidence of severe radiation-induced dermatitis when compared with no supplementation (96639). However, another small clinical study in patients with breast cancer who have had both chemotherapy and surgery shows that taking oral glutamine 5 grams three times daily, starting 1 week before radiation and continuing until 1 week after radiation, is associated with a reduction in grade 1 and grade 2 radiation dermatitis when compared with placebo (97366).
• Radiation-induced esophagitis. It is unclear if oral glutamine reduces the risk of developing esophagitis from radiation therapy. Details: A small clinical study in patients with advanced non-small cell lung cancer shows that taking glutamine 10 grams three times daily for 12 months along with a palliative dose of chemoradiotherapy (total 30 Gy) results in a 7% incidence of symptomatic (grade 2 or higher) radiation-induced esophagitis, compared with a 53% incidence with palliative chemoradiotherapy alone. The glutamine group also had a 5.8-day delay in the onset of esophagitis (100942). However, a lower dose of glutamine in patients receiving higher doses of radiotherapy might not be beneficial. A small clinical study in patients with advanced thoracic malignancies shows that taking glutamine 4 grams mixed in water twice daily for 4 weeks along with radiotherapy (total dose of at least 45 Gy) to the esophagus, with or without chemotherapy, does not slow the onset of radiation-induced esophagitis or reduce its severity when compared with a glycine placebo (105011).
• Short bowel syndrome. It is unclear if oral glutamine improves symptoms of short bowel syndrome. Details: Although small clinical studies suggest that glutamine plus growth hormone can decrease dependence on parenteral nutrition in some patients (2334,2361,2362,2703), it has not shown benefit for improving intestinal absorption of energy in all studies (8185). Additionally, glutamine alone doesn't appear to be beneficial (7730).
• Traumatic Brain injury (TBI). It is unclear if intravenous glutamine is beneficial in patients hospitalized with severe TBI. Details: A clinical trial in patients hospitalized for a severe TBI shows that adherence to a hypocaloric, low-protein diet supplemented with daily intravenous glutamine 0.3 g/kg for 7 days does not improve 28-day mortality when compared with standard nutritional support alone. However, it may reduce the length of ventilator use, hospitalization, and duration of intensive care unit stay (108034).
• Vincristine-induced neuropathy. It is unclear if oral glutamine reduces the risk of developing neuropathy from treatment with vincristine in children. Details: Preliminary clinical research in children ages 1-21 years receiving vincristine for various cancer types shows that taking glutamine 6 grams/m2 twice daily orally for 21 days reduces sensory neuropathy when compared with placebo. There was a significant improvement in self-reported, but not parent-reported, quality of life scores as measured by the PedsQL scale. However, there was no effect on motor neuropathy with the use of glutamine (96517).
• Wound healing. It is unclear if oral glutamine improves wound healing. Details: Preliminary clinical research in trauma patients with wound healing disorders shows that taking glutamine 20 grams orally daily in combination with ascorbic acid 500 mg, vitamin E 166 mg, beta-carotene 3.2 mg, selenium 100 mcg, and zinc 6.6 mg (Glutamine Plus, Fresenius Kabi) for 14 days reduces the time to wound closure by 29 days when compared with placebo. However, there is no difference in length of stay (97364). More evidence is needed to rate glutamine for these uses.

(Read more about GLUTAMINE)

POSSIBLY EFFECTIVE

• Schizophrenia. Oral glycine may improve negative, but not positive, symptoms of schizophrenia when used as adjunct to therapy with typical antipsychotics in patients resistant to monotherapy. However, glycine does not seem to provide additional benefit when used with clozapine. Details: Some small clinical trials show that taking glycine 0.4-0.8 grams/kg daily in divided doses along with conventional treatment seems to reduce negative symptoms of schizophrenia in patients that are resistant to monotherapy with typical antipsychotics such as thioridazine, haloperidol, and perphenazine (10250,10251,10252,98591). However, when used with the atypical antipsychotic clozapine, glycine appears to have a negligible effect on or worsen symptoms of schizophrenia (10253,11321). Additionally, glycine does not seem to improve positive symptoms of schizophrenia (10250,10251,10252,98591).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• 3-phosphoglycerate dehydrogenase (3-PGDH) deficiency. It is unclear if oral glycine is beneficial in patients with 3-PGDH deficiency. Details: A case series describing two patients with 3-PGDH deficiency who did not respond to serine supplementation suggests that taking oral glycine 0.2 grams/kg daily along with serine might reduce seizure frequency. 3-PGDH deficiency is a rare condition in which serine is not synthesized properly (10254).
• Aging. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in adults aged 61-80 years with overweight or obesity shows that taking a specific combination product (GlyNAC), providing glycine 100 mg/kg and N-acetyl cysteine 100 mg/kg, daily for 16 weeks improves some markers associated with aging, including glutathione levels, oxidative stress, mitochondrial impairment, genomic damage, inflammation, and endothelial dysfunction, when compared to baseline. Improvements in these measures were lacking in the placebo group (110624). The validity of these findings is limited by a lack of statistical comparison between groups. Also, it is unclear if these effects are due to glycine, N-acetyl cysteine, or the combination.
• Attention deficit-hyperactivity disorder (ADHD). Although there has been interest in using oral glycine for ADHD, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Benign prostatic hyperplasia (BPH). Although there has been interest in using oral glycine for BPH, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Cognitive function. Small clinical studies suggest that oral glycine may modestly improve memory and cognitive function in some patients. Details: Two small clinical studies in healthy young adults and adults with psychosis risk syndrome show that taking glycine 0.2-0.4 grams/kg once or twice daily for up to 24 weeks may improve some measures of memory and cognitive performance when compared with baseline or placebo (11322,92321).
• Cystic fibrosis. It is unclear if oral glycine is beneficial in patients with cystic fibrosis. Details: A small clinical trial in patients 6-23 years of age with cystic fibrosis shows that taking glycine 0.5 grams/kg daily for 8 weeks modestly improves some measures of lung function and reduces sputum and dyspnea by 15% and 23%, respectively, when compared with placebo. However, taking glycine does not improve appetite or energy (98583).
• Gout. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical study in patients with mild hyperuricemia shows that taking a powder containing glycine 3 grams and L-tryptophan 0.2 grams nightly at bedtime for 6 weeks reduces serum uric acid levels by 0.3 mg/dL when compared with placebo. Improvements also occurred in the subgroup of patients with uric acid levels greater than 7 mg/dL, the point at which symptoms of gout can occur (99883). However, it is unclear if this combination improves gout-related pain. Also, it is not clear if these findings are due to glycine, L-tryptophan, or the combination.
• Insomnia. Small clinical studies suggest that oral glycine may modestly improve sleep quality and daytime feelings of fatigue in patients with poor sleep quality or a restricted sleep duration. Details: Two very small studies in patients who have reported a subjective reduction in sleep quality show that taking glycine 3 grams one hour before bedtime for 2-4 days improves overall sleep quality and sleep efficacy when compared with placebo (92318,92320). Another very small clinical study in healthy males shows that taking glycine 3 grams 30 minutes before bedtime for 3 nights, during which time sleep duration is restricted by 25%, modestly reduces feelings of fatigue after the first night, but not after the third night, when compared with placebo (92316). The effects of glycine on sleep measures have also been evaluated in combination with other ingredients. A very small crossover study in healthy adults without documented sleep disorders shows that taking a combination product containing glycine 3000 mg, tryptophan 1000 mg, magnesium 300 mg, tart cherry powder 220 mg, and L-theanine 200 mg before bed for 3 nights reduces sleep onset latency, increases total sleep time, increases sleep efficiency, and reduces morning sleepiness when compared with placebo (111184). It is unclear if these effects are due to glycine, other ingredients, or the combination.
• Isovaleric acidemia. Although there has been interest in using oral glycine for isovaleric acidemia, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Metabolic syndrome. Although there has been interest in using oral glycine for metabolic syndrome, there is insufficient reliable information about the clinical effects of glycine for this purpose.
• Obesity. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in adults aged 61-80 years with overweight or obesity shows that taking a specific combination product (GlyNAC), providing glycine 100 mg/kg and N-acetyl cysteine 100 mg/kg, daily for 16 weeks reduces waist circumference but does not improve body weight or body mass index (BMI) when compared to baseline. None of these outcomes were improved in individuals taking placebo (110624). The validity of these findings is limited by a lack of statistical comparison between groups. Also, it is unclear if these effects are due to glycine, N-acetyl cysteine, or the combination.
• Overactive bladder. It is unclear if oral glycine is beneficial in patients with overactive bladder. Details: One very small, non-randomized, crossover trial in patients with overactive bladder shows that taking glycine 3 grams twice daily for 4 weeks reduces urinary urgency, urinary incontinence, and nighttime urinary frequency and improves quality of life scores when compared with placebo (106497). The validity of these findings is limited by a lack of randomization.
• Physical performance. Oral glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in adults aged 61-80 years with overweight or obesity shows that taking a specific combination product (GlyNAC), providing glycine 100 mg/kg and N-acetyl cysteine 100 mg/kg, daily for 16 weeks improves upper and lower extremity strength and gait speed, but not walking distance, when compared to baseline. None of these outcomes were improved in individuals taking placebo (110624). The validity of these findings is limited by a lack of statistical comparison between groups. Also, it is unclear if these effects are due to glycine, N-acetyl cysteine, or the combination.
• Stroke. It is unclear if sublingual glycine is beneficial in patients with acute ischemic stroke. Details: One small clinical study in patients with acute ischemic stroke in the carotid artery territory shows that taking glycine 1-2 grams sublingually daily for 5 days, starting within 6 hours after the onset of stroke, modestly improves clinical outcomes on the Orgogozo Stroke Scale, the Scandinavian Stroke Scale, and the Barthel index when compared with placebo (11320).
• Venous leg ulcers. Topical glycine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study shows that applying a cream containing glycine, L-cysteine, and DL-threonine to leg ulcers reduces pain and modestly improves healing when compared with a placebo cream (10255). It is unclear if these effects are due to glycine, other ingredients, or the combination.
• Wound healing. Although there has been interest in using topical glycine for wound healing, there is insufficient reliable information about the clinical effects of glycine for this purpose. More evidence is needed to rate glycine for these uses.

(Read more about GLYCINE)

LIKELY EFFECTIVE

• Benign prostatic hyperplasia (BPH). Most clinical research shows that taking oral pygeum reduces the frequency and severity of BPH symptoms in adults. However, it is unclear how pygeum compares with the standard prescription medications. Details: Meta-analyses of randomized clinical trials show that adults with BPH who take oral pygeum 75-200 mg daily for 60-90 days are about twice as likely to have improvement in BPH symptoms as those taking placebo. Taking pygeum also increases peak urine flow by 23% and reduces residual urine volume by 24% in patients with BPH (10425,10426). Preliminary clinical research also shows that once daily dosing is as effective as twice daily dosing (6368). Pygeum has also been evaluated in combination with other ingredients. One small study shows that taking a specific combination product (ProstateEZE Max, Caruso's Natural Health) containing pygeum, pumpkin seed oil, Epilobium parviflorum, lycopene, and saw palmetto as 1 capsule daily for 3 months decreases daytime urinary frequency by an additional 16% and nighttime urinary frequency by an additional 32% when compared with placebo (92164). In another clinical trial, taking a combination of pygeum and stinging nettle for 6 months did not improve BPH symptoms when compared with placebo; however, the study may have been inadequately powered to detect a difference between groups (70219).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alzheimer disease. Although there has been interest in using oral pygeum for Alzheimer disease, there is insufficient reliable information about the clinical effects of pygeum for this purpose.

  
  Malaria. Although there has been interest in using oral pygeum for malaria, there is insufficient reliable information about the clinical effects of pygeum for this purpose.

  
  Psychosis. Although there has been interest in using oral pygeum for psychosis, there is insufficient reliable information about the clinical effects of pygeum for this purpose.

  
  Sexual desire. Although there has been interest in using oral pygeum for sexual desire, there is insufficient reliable information about the clinical effects of pygeum for this purpose.

  
  More evidence is needed to rate pygeum for these uses.

(Read more about PYGEUM)

POSSIBLY EFFECTIVE

• Transurethral resection of the prostate (TURP). Saw palmetto 320 mg daily seems to improve outcomes after TURP surgery in a dose-dependent manner. Details: Clinical research shows that taking saw palmetto (Permixon, Pierre Fabre Medicament) 320 mg daily for 2 months prior to TURP surgery reduces blood loss, the duration of surgery, the development of intraoperative complications, the duration of catheterization, and the length of hospitalization when compared with placebo (73323,73353). Although these studies found benefit, a small study using a lower dose of saw palmetto (Prostagood Mono, Abdi Ibrahim) 160 mg orally once daily for 5 weeks prior to TURP did not find any decrease in the risk of perioperative hemorrhage, or the density of prostate tissue (17202).

POSSIBLY INEFFECTIVE

• Benign prostatic hyperplasia (BPH). Although individual study results are conflicting, the overall body of evidence suggests that saw palmetto does not offer clinically meaningful improvements in BPH-related symptoms. Details: Research on the use of saw palmetto for improving symptoms of BPH is inconsistent and contradictory. To date, the best available evidence addressing the effectiveness of saw palmetto in patients with BPH comes from two high-quality clinical trials sponsored by the National Institutes of Health (NIH). In one of these trials, saw palmetto 160 mg twice daily for one year was ineffective for reducing moderate to severe symptoms of BPH when compared with placebo (14274). In the other trial, taking saw palmetto 320-960 mg daily for 72 weeks did not significantly improve symptoms when compared with placebo (17684). Additionally, meta-analyses of these trials and many of the small trials described below show that taking saw palmetto does not improve BPH-related signs and symptoms or International Prostate Symptom Scores (IPSS) (89441,102835). While several small, low-quality clinical trials and observational studies in patients with BPH suggest that saw palmetto provides some improvement in urinary symptoms, nocturia, urinary flow, and/or residual urine volume when compared with placebo or baseline (6750,6764,6772,73315,73383,73385,73387,89441,96570,110541), other studies show that saw palmetto has no clinically meaningful effect on BPH-related signs and symptoms, including prostate volume (5093,6752,11314,73343,96409). The validity of several of these studies is limited due to the use of per-protocol analyses and/or a lack of placebo control groups. Beyond this, reasons for these discrepant findings are unclear; however, the mixed results may be due to use of different saw palmetto products, varying study methodologies, different patient populations, and varying symptom scoring tools. Additionally, research shows significant variation in the chemical composition of commercially available saw palmetto extracts (17305,89441). Several clinical trials have compared saw palmetto to 5-alpha reductase inhibitors such as finasteride (Proscar) or dutasteride (Avodart). Some small studies suggest that it may be comparable to these medications for relieving BPH symptoms, but with less effect on prostate size or prostate-specific antigen (PSA) levels (6424,96570). It may also be better tolerated, with a positive effect on sexual dysfunction (6424,6763,18215,89441). Additionally, one observational study in patients with BPH has found that taking saw palmetto 320 mg with tamsulosin 0.4 mg daily for 6 months is associated with similar improvements in IPSS and quality of life scores, but also has a lower risk of reduced libido, when compared with tamsulosin plus dutasteride 5 mg or finasteride 0.5 mg daily (110542). Some research has also compared saw palmetto to alpha-adrenergic blockers. Alpha-adrenergic blockers appear to have a faster onset of symptom relief (2732,6750), and saw palmetto might be less effective than the alpha-adrenergic blocker prazosin (Minipress). Although some studies and a meta-analysis suggest it is similarly effective to tamsulosin (Flomax) after 6-12 months of treatment for improving various symptoms of BPH (6775,6776,11243,89441,96570,104804,107483), another meta-analysis found that alpha-blockers were more effective than saw palmetto for these outcomes (102835). Additionally, tamsulosin appears to be more effective than saw palmetto for reducing prostate volume (104802). However, some research suggests that saw palmetto may be better tolerated than tamsulosin (107483). It is unclear if taking saw palmetto with tamsulosin can improve BPH symptoms. Several low-quality studies and a meta-analysis of two of these studies show no additional benefit over using tamsulosin alone (8901,89443,89448,96410). However, one study suggests that a specific saw palmetto extract (Permixon, Pierre Fabre Medicament) 320 mg daily is associated with a 29% decrease in the IPSS when taken alone, compared with a 37% decrease when taken along with tamsulosin 0.4 mg daily for 6 months. Tamsulosin alone was associated with a 31% decrease (104802). Smaller, lower-quality studies of various combinations of saw palmetto with other ingredients have demonstrated some benefit for improving symptoms of BPH, and some have shown equivalence to finasteride, tamsulosin, or tadalafil (Cialis). These ingredients include stinging nettle root (PRO 160/120, Dr. Willmar Schwabe Pharmaceuticals) (6763,17307,73330,89441); cernitin, beta-sitosterol, and vitamin E (11241); selenium and lycopene (Profluss, Konpharma) (90354,97255); pygeum, lycopene, Epilobium parviflorum, and pumpkin seed oil (ProstateEZE Max, Caruso's Natural Health) (92164); and quercetin and beta-sitosterol (Difaprost, Difass International) (96784). Additionally, one study suggests that an enriched form of saw palmetto oil containing 3% beta-sitosterol seems to be more effective than standard saw palmetto oil containing 0.3% beta-sitosterol in reducing IPSS scores (104803).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Androgenic alopecia. It is unclear if oral or topical saw palmetto is beneficial in patients with androgenic alopecia. Details: Clinical research shows that a combination of saw palmetto extract 200 mg plus beta-sitosterol 50 mg taken twice daily for 18-24 months improves subjective scores of hair quantity and quality in males with androgenic alopecia (15550). However, other clinical research shows that taking saw palmetto extract 320 mg daily for 24 months is less effective for improving hair growth in males with androgenic alopecia when compared with finasteride 1 mg daily (89444). Some clinical research shows that saw palmetto lotion applied topically twice daily for 50 weeks improves hair density by 27% in people with androgenic alopecia. However, a 13% improvement was observed in the placebo group, and no between-group comparisons were made (73435). Additionally, a small clinical study in males with androgenic alopecia receiving platelet-rich plasma every 3 weeks shows that applying 1 mL of topical saw palmetto, redensyl, and biotin daily for 12 weeks modestly improves subjective hair loss scores and photographic assessment of hair growth when compared with 1 mL of topical Procapil daily (112176). However, it is unclear if this effect is due to saw palmetto, other ingredients, or the combination.
• Asthma. Although there has been interest in using oral saw palmetto for asthma, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Chronic bronchitis. Although there has been interest in using oral saw palmetto for chronic bronchitis, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS). It is unclear if oral saw palmetto is beneficial in patients with CP/CPPS. Details: Preliminary clinical research shows that oral saw palmetto 325 mg daily for one year does not significantly improve symptoms of CP/CPPS when compared with finasteride 5 mg once daily (11354). However, a clinical trial in patients with moderate to severe CP/CPPS shows that taking saw palmetto 160 mg orally twice daily for 12 weeks improves NIH Chronic Prostatitis Index (NIH-CPSI) score after two weeks of treatment in patients with moderate disease and after 4 weeks of treatment in patients with severe disease when compared with placebo. Independent of severity, 73% of patients taking saw palmetto report a 6-point reduction in NIH-CPSI total score, compared to 33% of patients taking placebo (107482). Saw palmetto extract has also been evaluated in combination with other ingredients. A preliminary clinical study shows that taking a combination of saw palmetto extract 320 mg, selenium 50 mcg, and lycopene oil extract 5 mg daily for 8 weeks improves symptoms and peak flow in patients with CP/CPPS when compared with baseline. However, these effects were not observed or were less significant in patients treated with saw palmetto alone (60442).
• Common cold. Although there has been interest in using oral saw palmetto for the common cold, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Hirsutism. Although there has been interest in using oral and topical saw palmetto for hirsutism, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Non-neurogenic lower urinary tract symptoms (LUTS). It is unclear if oral saw palmetto is beneficial in females with non-neurogenic LUTS. Details: A small clinical study in elderly Japanese females with LUTS shows that taking saw palmetto extract 320 mg daily for 12 weeks reduces daytime urinary frequency and might improve nocturia, but it does not seem to reduce urinary urgency, incontinence, straining, bladder pain, or urethral pain when compared with placebo (110540).
• Prostate cancer. Small preliminary studies suggest that saw palmetto does not reduce prostate cancer risk or symptoms associated with prostate cancer. Details: Population research shows that people who take saw palmetto supplements do not have a lower risk of developing prostate cancer (15217). Preliminary clinical research also shows that taking saw palmetto 960 mg daily before, during, and after radiation treatment for early prostate cancer does not significantly improve lower urinary tract symptoms when compared with placebo (96412).
• Prostatitis. Adding saw palmetto to antibiotic therapy seems to relieve some symptoms of bacterial prostatitis more effectively than antibiotics alone. Details: Preliminary clinical research in patients with bacterial prostatitis shows that taking saw palmetto extract daily for eight weeks, with prulifloxacin 600 mg daily for 15 days, reduces pain and urinary symptoms more than prulifloxacin alone, but the combination does not appear to improve bacterial eradication or sexual dysfunction more than the antibiotic alone (89442). One small clinical study in patients with chronic nonbacterial prostatitis shows that a specific saw palmetto extract (Prostamol Uno, Profluss) 320 mg daily improves symptoms when compared with no treatment (73329). Combinations of saw palmetto with other supplements have also been used with fluoroquinolone antibiotics, typically resulting in symptom improvement when compared with the antibiotic alone. These supplement combinations include saw palmetto, indole-3-carbinol, and epigallocatexin-3-gallate (Indigal Plus) 2 capsules twice daily for 3 months (73355); saw palmetto 160 mg, stinging nettle 120 mg, curcumin 200 mg, and quercetin 100mg (ProstaMEV plus FlogMEV) for 2 weeks (73346); and saw palmetto 320 mg, Bacillus coagulans 200 mg, and arbutin 100 mg (Lactorepens) daily for 30 days (96411).
• Sexual desire. Although there has been interest in using oral saw palmetto for sexual desire, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose.
• Sexual dysfunction. Although there has been interest in using oral saw palmetto for sexual dysfunction, there is insufficient reliable information about the clinical effects of saw palmetto for this purpose. More evidence is needed to rate saw palmetto for these uses.

(Read more about SAW PALMETTO)

LIKELY SAFE ...when used in amounts commonly found in foods.

POSSIBLY SAFE ...when used orally and appropriately. Alpha-alanine 100-140 mg/kg daily has been used with apparent safety for up to 3 months (16026,16027,16444). A single dose of alanine 40 grams has also been used with apparent safety (14612,16019,16020).

CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term. Alanine 90 mmol/L, as a component of an oral rehydration solution, has been used with apparent safety for approximately 48 hours in children age 3-48 months (16021).

PREGNANCY AND LACTATION: LIKELY SAFE
when used in amounts commonly found in foods. There is insufficient reliable information available about the safety of using larger amounts as medicine during pregnancy or lactation.

(Read more about ALANINE)

LIKELY SAFE ...when used orally and appropriately. Glutamine has been safely used in clinical research in doses up to 40 grams per day or 1 gram/kg daily (2334,2337,2338,2365,5029,5462,7233,7288,7293), (52288,52307,52308,52311,52313,52337,52349,52350,96516,97366). A specific glutamine product (Endari) is approved by the US Food and Drug Administration (FDA) (96520). ...when used intravenously. Glutamine has been safely incorporated into parenteral nutrition in doses up to 600 mg/kg daily in clinical trials (2363,2366,5448,5452,5453,5454,5458,7293,52272,52275), (52283,52289,52304,52306,52316,52341), (52359,52360,52371,52377,52381,52284,52385,52408,96637,96507,96516).

CHILDREN: LIKELY SAFE
when used orally and appropriately. Glutamine has been shown to be safe in clinical research when used in amounts that do not exceed 0.7 grams/kg daily in children 1-18 years old (11364,46657,52321,52323,52363,86095,96517). A specific glutamine product (Endari) is approved by the US Food and Drug Administration for certain patients 5 years of age and older (96520). ...when used intravenously. Glutamine has been safely incorporated into parenteral nutrition in doses up to 0.4 grams/kg daily in clinical research (52338,96508). There is insufficient reliable information available about the safety of glutamine when used in larger amounts in children.

PREGNANCY AND LACTATION: LIKELY SAFE
when consumed in amounts commonly found in foods. There is insufficient reliable information available about the safety of glutamine when used in larger amounts as medicine during pregnancy or lactation.

(Read more about GLUTAMINE)

POSSIBLY SAFE ...when used orally and appropriately. Glycine has been used safely at doses up to 6 grams daily for 4 weeks (106497) and doses up to 9 grams daily for 3 days (10250,10251,10252,92319). There is insufficient reliable information available about the safety of glycine when used topically.

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

(Read more about GLYCINE)

LIKELY SAFE ...when used orally and appropriately. Pygeum 75-200 mg daily has been used safely in clinical trials for up to 12 months (3903,6368,10425,10426).

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

(Read more about PYGEUM)

LIKELY SAFE ...when used orally and appropriately. Saw palmetto has been safely used in clinical studies lasting up to 3 years (2735,6750,6752,6764,6772,6773,11354,14274,15550,17202,17306,17684,73315,73383,73384,73385,73389,89441,96410,96412,110540).

POSSIBLY SAFE ...when used rectally and appropriately. Saw palmetto has been used safely in clinical research at a dose of 640 mg once daily for 30 days (73387). However, the long-term safety of saw palmetto administered rectally is not known.

PREGNANCY AND LACTATION: LIKELY UNSAFE
when used orally. Saw palmetto has hormonal activity (6766); avoid using.

(Read more about SAW PALMETTO)

(Read more about ALANINE)

ANTICONVULSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, glutamine might antagonize the effects of anticonvulsant medications.  Details Glutamine is metabolized to the excitatory neurotransmitter glutamate. Glutamate might have antagonistic effects with anticonvulsant drugs (7292,7293,7294). However, this interaction has not yet been reported in humans.

(Read more about GLUTAMINE)

CLOZAPINE (Clozaril) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Theoretically, glycine might decrease the effectiveness of clozapine.  Details One small clinical study in patients with schizophrenia shows that adding glycine to clozapine therapy worsens symptoms of schizophrenia when compared with clozapine alone (10253). The mechanism of this interaction is unclear.

(Read more about GLYCINE)

(Read more about PYGEUM)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Saw palmetto might increase the risk of bleeding with anticoagulant or antiplatelet drugs.  Details Saw palmetto is reported to prolong bleeding time (8659). Theoretically, it might increase the risk of bleeding when used concomitantly with anticoagulant or antiplatelet drugs.

CONTRACEPTIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Saw palmetto might reduce the effectiveness of contraceptive drugs.  Details Saw palmetto might have antiestrogenic effects (6766). Theoretically, it might interfere with contraceptive drugs taken concomitantly.

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Saw palmetto might reduce the effectiveness of estrogens.  Details Saw palmetto might have antiestrogenic effects (6766). Theoretically, it might interfere with estrogens taken concomitantly.

(Read more about SAW PALMETTO)

General ...There is currently a limited amount of information on the adverse effects of alanine.

(Read more about ALANINE)

General ...Orally and intravenously, glutamine is generally well tolerated.
Most Common Adverse Effects:
Orally: Belching, bloating, constipation, cough, diarrhea, flatulence, gastrointestinal pain, headache, musculoskeletal pain, nausea, and vomiting.

Endocrine ...One case of hot flashes has been reported in a patient taking glutamine 5-15 grams orally twice daily for up to 1 year (96520).

Gastrointestinal ...Orally, glutamine has been associated with belching, bloating, constipation, flatulence, nausea, vomiting, diarrhea, and gastrointestinal (GI) pain. Nausea, vomiting, constipation, diarrhea, and GI pain have been reported in clinical trials using high-dose glutamine 10-30 grams (0.3 grams/kg) in two divided doses daily to treat sickle cell disease (99414). One case of dyspepsia and one case of abdominal pain have been reported in patients taking glutamine 5-15 grams twice daily orally for up to 1 year (96520). In a small trial of healthy males, taking a single dose of about 60 grams (0.9 grams/kg of fat free body mass [FFM]) was associated with a 50% to 79% incidence of GI discomfort, nausea, and belching, compared with a 7% to 28% incidence with a lower dose of about 20 grams (0.3 gram/kg FFM). Flatulence, bloating, lower GI pain, and urge to regurgitate occurred at similar rates regardless of dose, and there were no cases of heartburn, vomiting, or diarrhea/constipation (105013). It is possible that certain GI side effects occur only after multiple doses of glutamine.

Musculoskeletal ...Orally, glutamine 30 grams daily has been associated with cases of musculoskeletal pain and non-cardiac chest pain in clinical trials for patients with sickle cell disease (99414).

Neurologic/CNS ...Orally, glutamine has been associated with dizziness and headache. A single case of dizziness has been reported in a patient treated with oral glutamine 0.5 grams/kg. However, the symptom resolved after reducing the dose to 0.25 grams/kg (91356). Mania and hypomania have been reported in 2 patients with bipolar disorder taking commercially purchased glutamine up to 4 grams daily (7291). Glutamine is metabolized to glutamate and ammonia, both of which might have neurological effects in people with neurological and psychiatric diseases or in people predisposed to hepatic encephalopathy (7293).

Oncologic ...There is some concern that glutamine might be used by rapidly growing tumors and possibly stimulate tumor growth. Although tumors may utilize glutamine and other amino acids, preliminary research shows that glutamine supplementation does not increase tumor growth (5469,7233,7738). In fact, there is preliminary evidence that glutamine might actually reduce tumor growth (5469).

Other ...Orally, glutamine has been associated with cough when a powdered formulation is used. It is unclear if this was due to accidental inhalation. One case of a burning sensation and one case of hypersplenism has been reported in a patient taking glutamine 5-15 grams twice daily orally for up to 1 year (96520).

(Read more about GLUTAMINE)

General ...Orally and topically, glycine seems to be well tolerated.

Gastrointestinal ...Soft stools, nausea, vomiting, and upper gastrointestinal (GI) tract discomfort have occurred rarely with oral use of glycine. These symptoms resolve rapidly with discontinuation of glycine (10252,11320,92319). Dry mouth has also been reported but any association to glycine is unclear (92321).

Neurologic/CNS ...Mild sedation has occurred rarely with oral use of glycine. Symptoms resolve rapidly with discontinuation of glycine (10252,11320,92321). Irritability, insomnia, fatigue, memory impairment, headache, and sensory impairment have been reported, but any association with glycine is unclear (92321).

(Read more about GLYCINE)

General ...Orally, pygeum is generally well tolerated.

Gastrointestinal ...Orally, pygeum has been associated with nausea and abdominal pain in some clinical research. However, the rate of these events were similar to placebo (10425,10426,70238).

(Read more about PYGEUM)

General ...Orally, saw palmetto is well tolerated and adverse effects are mild, infrequent, and reversible.
Most Common Adverse Effects:
Orally: Abdominal pain, constipation, decreased libido, diarrhea, dizziness, fatigue, headache, nausea, rhinitis, vomiting.

Cardiovascular ...Occasionally, cases of hypertension, postural hypotension, tachycardia, angina pectoris, arrhythmia, extrasystole, angiopathy, myocardial infarction, and congestive heart failure have been reported in patients using saw palmetto orally (6424,6484,6752,6772,17684,73388,89441). One case of severe bradycardia and second degree heart block was reported in a 64 year-old male taking an unknown amount of saw palmetto for a few weeks (96413).

Dermatologic ...A case report describes a 61-year-old male who developed a fixed drug eruption with localized blisters and erosions three days after starting oral saw palmetto. The lesions resolved when saw palmetto was stopped, but recurred when it was reintroduced six months later. Topical corticosteroid treatment was necessary and the patient was left with some residual hyperpigmented patches (104805). A combination of saw palmetto and beta-sitosterol has been associated with a single report of worsening acne (15550).

Endocrine ...Two case reports involving one 11-year-old female undergoing treatment for telogen effluvium and another 10-year-old female undergoing treatment for hirsutism, describe hot flashes and the onset of menarche associated with use of saw palmetto. One of these patients was consuming saw palmetto in a food supplement; the other was taking a supplement containing saw palmetto 320 mg daily (73361,96414). In both cases, the hot flashes resolved following treatment discontinuation. In one case, a rechallenge with saw palmetto caused a recurrence of hot flashes.

Gastrointestinal ...Gastrointestinal complaints such as nausea, vomiting, constipation, diarrhea, gastralgia, and halitosis are the most frequently reported adverse effects associated with saw palmetto (6484,6752,60442,73315,73320,73348,73354,73383,73385,73388,89441). Less often, cases of duodenal ulcer, dyspepsia, or heartburn have been reported (6772,73329,73354). Meteorism (intestinal gas accumulation) has also been reported with saw palmetto, although causality was unclear (60442).

Genitourinary ...Some clinicians are concerned that saw palmetto might cause erectile dysfunction, ejaculatory disturbance, or altered libido because of its potential effects on 5-alpha-reductase. Some preliminary clinical studies have reported sexual dysfunction, particularly ejaculatory dysfunction, erectile dysfunction, and reduced libido, in patients taking saw palmetto (5093,17202,17684,73383,89441). However, most of these patients were previously diagnosed with prostate disorders, so causality is unclear. Additionally, several clinical studies indicate that the occurrence of impotence in males taking saw palmetto is similar to placebo and tamsulosin (Flomax), and significantly less than finasteride (Proscar) (2732,6424,17306,107481). Rarely, cases of testicular pain, vesical tenesmus, and urinary tract infections have been reported in patients using saw palmetto extract orally (73388).

Hematologic ...Saw palmetto might have antiplatelet effects and potentially increase the risk of bleeding in some patients. There is one report of excessive intraoperative bleeding in a patient who took saw palmetto prior to surgery. Bleeding time normalized when saw palmetto was discontinued (8659). Also, one case of cerebral hemorrhage has been reported, but details are not available to determine causality (6772,73348). A case of retroperitoneal hematoma after bilateral inguinal hernia repair is reported in a male patient taking saw palmetto. The patient was discharged after a 3-day hospitalization in stable condition (112177).

Hepatic ...A case report describes a patient who developed acute hepatitis and pancreatitis while taking saw palmetto. Symptoms resolved when saw palmetto was discontinued, and reemerged upon re-challenge (14457). Other cases of acute hepatitis and pancreatitis, with elevated alkaline phosphatase, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and bilirubin have been reported in patients using saw palmetto orally (14457,73350,73351).

Musculoskeletal ...Orally, saw palmetto may cause fatigue, weakness, muscle pain, and back pain, although these adverse events are rare (6424,73388,89441). A case of saw palmetto-related rhabdomyolysis was reported in an 82-year-old male presenting with kidney dysfunction, increased C-reactive protein levels, and elevated serum creatine kinase (73358).

Neurologic/CNS ...Orally, saw palmetto can cause headaches, dizziness, insomnia, and fatigue (6750,6752,6772,11354,60442,73348,73385,73388,89441).

Ocular/Otic ...A case of intraoperative floppy-iris syndrome (IFIS) has been reported in a patient using saw palmetto orally (73340). However, no statistically significant association between saw palmetto and IFIS was found in a case series of 660 patients undergoing cataract surgery (73347).

Pulmonary/Respiratory ...Rhinitis is one of the more commonly reported adverse effects of saw palmetto (73348). One patient taking saw palmetto extract 160 mg twice daily reported "breathlessness" (73388). Two cases of respiratory depression have been reported in patients using saw palmetto extract (Permixon) 320 mg (6772).

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