Detox Herbal Tea Skinny (Hibiscus Fire flavor) by Greenside

POSSIBLY EFFECTIVE

• Osteoarthritis. Topical arnica gel might reduce osteoarthritis pain. Details: One open-label clinical trial shows that applying arnica gel (A. Vogel Arnica Gel, Bioforce AG) twice daily for 3 weeks decreases total symptom scores, including pain, stiffness, and restriction-of-function, when compared to baseline (19112). A larger randomized clinical trial shows that applying the same gel is as effective as ibuprofen for reducing the intensity of pain and improving hand function (19108).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Although there is interest in using topical arnica for acne, there is insufficient reliable information about the clinical effects of arnica for this purpose.
• Bleeding. It is unclear if oral arnica reduces bleeding after surgery. Details: A small clinical study in patients undergoing total mastectomy for breast cancer suggests that sublingual treatment with 5 drops of a homeopathic preparation of arnica extract (Arnica 1000 K) three times daily for 6 days might reduce the volume of blood and serum drainage by 95 mL over 5 days when compared with placebo (96769). However, because this product is a dilute homeopathic preparation, there is unlikely to be any arnica in the doses given. There is speculation that the slightly higher mean weight of the patients in the arnica group, rather than any effects of arnica itself, might have led to the statistically significant findings (96768).
• Breast cancer-related hot flashes. Oral homeopathic arnica has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A clinical study in females with non-metastatic breast cancer treated with tamoxifen or an aromatase inhibitor shows that taking a specific homeopathic medicine (Actheane, Laboratories Boiron) daily for 3 months does not reduce hot flashes when compared with placebo. This product contains 4CH each of arnica, black cohosh, bloodroot, and nitroglycerin and 5CH of snake Lachesis muta (103004).
• Bruises. Most small clinical trials show that neither topical nor oral arnica reduces postoperative bruising. Details: Most clinical research shows that topical products containing arnica 10%, as well as homeopathic oral products such as tablets, globules, and capsules, are not effective for reducing postoperative bruising (19107,19119,19120,19121,19122,19123,19124,90611,96769,96772). However, some conflicting research shows benefit. One clinical study shows that applying arnica 20% ointment 0.25 grams twice daily for 2 weeks reduces laser-induced bruising when compared to white petrolatum ointment (19125). Another clinical study shows that applying a specific arnica cream (Arnica Krem 75 g, MediTech) four times daily reduces periorbital bruising in the first week after rhinoplasty when compared with no local treatment (96773). One small study has also evaluated oral homeopathic arnica. In females undergoing a face-lift, taking a specific homeopathic oral arnica product (SinEcch, Alpine Pharmaceuticals) may reduce bruising on postoperative days 1 and 7 when compared with placebo (19124).
• Diabetic retinopathy. Small clinical studies suggest that oral homeopathic arnica may reduce symptoms of diabetic retinopathy. Details: Two preliminary clinical trials in patients with diabetic retinopathy associated with both type 1 and type 2 diabetes shows that taking three pearls of homeopathic arnica 5C orally for 6 months might modestly improve measures of vision when compared with placebo (19110,19111).
• Dry eye. It is unclear if eye drops containing arnica extract can improve dry eye in children. Details: A small observational study in children aged 9-14 years with dry eye disease and allergic conjunctivitis suggests that applying eye drops containing hyaluronic acid 0.2% and arnica extract 0.1% three times daily for four weeks is associated with improvements in subjective and objective measures of dry eye severity when compared to baseline. Improvements in these outcomes were smaller and mostly non-significant in patients using eye drops containing hyaluronic acid only (111421). The validity of these findings is limited by a lack of between-group analysis and randomization.
• Exercise-induced muscle soreness. Small studies suggest that oral homeopathic arnica does not reduce muscle soreness after exercise. It is unclear if topical arnica is beneficial. Details: Despite some conflicting evidence (19135), most clinical research shows that taking homeopathic arnica formulations orally does not prevent delayed-onset muscle soreness (19129,19130,19131,19132,19133). Research on the use of topical arnica formulations is conflicting. One small study in trained athletes shows that using a gel containing 25 mg of dry arnica herb on muscles immediately after a run and then every 4 hours while awake for 5 days improves muscle tenderness and pain by a small amount after 3 days, but not at other time points, when compared with placebo (90612). However, another small study suggests that applying arnica 7% cream (Boiron Group) increases muscle pain following calf raises when compared with placebo (17113).
• Postoperative swelling. It is unclear if topical arnica reduces swelling after surgery. Details: One clinical study shows that applying arnica 10% ointment following blepharoplasty does not reduce postoperative swelling when compared with using a placebo ointment (96772). However, lower quality studies have yielded more promising results. One small clinical study shows that applying a specific arnica cream (Arnica Krem 75 g, MediTech) four times daily reduces swelling by a small amount in the first week after rhinoplasty when compared with no local treatment (96773). The validity of this finding is limited by the lack of a placebo control. A small retrospective study suggests that using a topical homeopathic preparation containing arnica 50M and marsh tea 50M (OcuMend, Cearna Inc.) is associated with reduced postoperative swelling after oculofacial surgery (96770); however, this study is limited by poor design (96771).
• Postoperative pain. Findings related to the use of oral homeopathic arnica are mixed; most studies utilizing a placebo control have yielded negative results. Details: Many small clinical studies show that taking homeopathic arnica preparations orally modestly reduces postoperative pain following tonsillectomy, knee surgery, and carpal tunnel release when compared with baseline or control. Most studies have used homeopathic arnica in dilutions of 30C, 30X, D6, or D4, for up to two weeks postoperatively (19102,19114,19115,19116). In one study, oral homeopathic arnica has been used along with arnica 5% ointment from 72 hours after surgery for up to 2 weeks (19116). The validity of these findings is limited by the lack of a placebo comparator. Studies utilizing a placebo or active control have not yielded positive results. Clinical research in patients recovering from carpal tunnel surgery shows that taking a homeopathic Arnica montana solution by mouth is no more effective than taking placebo for reducing postoperative pain and bruising (19107). Other clinical research shows that taking homeopathic arnica 30C for 5 days after total abdominal hysterectomy does not reduce postoperative pain when compared with placebo and usual treatment (19117). Also, homeopathic arnica D4 is inferior to diclofenac following bunion surgery (109102). Some clinical research in patients recovering from a knee ligament reconstruction shows that a homeopathic solution containing Arnica montana 5 CH, Bryonia alba 5 CH, Hypericum perforatum 5 CH, and Ruta graveolens 3 DH is no more effective than placebo for reducing analgesic use (32413).
• Postoperative recovery. It is unclear if oral homeopathic arnica is beneficial for postoperative recovery. Details: One meta-analysis of small- to moderate-sized clinical trials shows that taking homeopathic arnica does not improve postoperative recovery when compared with controls. Recovery endpoints were combined and included pain, swelling, bruising, wound healing, and others (109061).
• Stroke. A small study suggests that oral homeopathic arnica does not improve outcomes after stroke. Details: Preliminary clinical research shows that taking one tablet of arnica 30C sublingually every 2 hours for six doses doesn't benefit stroke patients (19126). Endpoints included level of consciousness, mobility, incontinence, social performance, and mental state.
• Tooth extraction. It is unclear if oral homeopathic arnica improves symptoms after tooth extraction in adults or children. Details: A small clinical trial in children aged 8-12 years undergoing two sessions of tooth extraction in different parts of the mouth shows that taking homeopathic arnica 30 minutes prior to the procedure, and then 3 times daily for 72 hours, is as effective as taking ibuprofen for reducing patient-reported and operator-assessed pain levels 24 hours after extraction. However, 48 hours after extraction, ibuprofen was more effective. Each child was provided with both arnica and weight-based doses of ibuprofen in a crossover manner while undergoing two sessions of tooth extraction in different parts of the mouth ten days apart (109224). A small observational study in adults undergoing third molar extractions suggests that taking homeopathic arnica 30X (Hyland's Inc.) 4 tablets before the procedure and then 4 tablets four times daily for 4 days after the procedure is associated with less pain, bleeding, and swelling when compared with standard treatment alone (105062). However, the validity of this study is limited by the lack of a placebo control. More evidence is needed to rate arnica for these uses.

(Read more about ARNICA)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Benign prostatic hyperplasia (BPH). Oral boldo has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with BPH, some of whom were already receiving conventional treatment such as alpha-1 blockers, shows that taking a specific product containing water-soluble extracts of boldo, goldenrod, chanca piedra, fireweed, and spiny restharrow (Fluxonorm, Omega Pharma) orally for 30 days improves lower urinary tract symptom scores by about 50% when compared with baseline. Maximum urinary flow rate and quality of life were also improved when compared with baseline (106432). The validity of these findings is limited by the lack of a comparator group.
• Gallbladder disease. Although there has been interest in using oral boldo for gallbladder disease, there is insufficient reliable information about the clinical effects of boldo for this purpose.
• Gonorrhea. Although there has been interest in using oral boldo for gonorrhea, there is insufficient reliable information about the clinical effects of boldo for this purpose.
• Kidney stones (nephrolithiasis). Oral boldo has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in children 6-18 years of age with upper ureteral tract kidney stones shows that taking a specific combination product containing boldo 200 mg, uva ursi 300 mg and Herniaria hirsuta 40 mg (Renalit-combi, Bio-Stilogit Pharmaceuticals) orally for 12 days each month for 3 months after undergoing lithotripsy, in addition to standard care, reduces presence of residual stone fragments by 58% when compared with standard care alone (109936).
• Joint pain. Although there has been interest in using oral boldo for joint pain, there is insufficient reliable information about the clinical effects of boldo for this purpose. More evidence is needed to rate boldo for these uses.

(Read more about BOLDO)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Athletic performance. It is unclear if oral garcinia is beneficial for improving athletic performance. Details: Two very small, exploratory studies in untrained females and in elite athletes show that taking hydroxycitric acid (HCA), the active ingredient of garcinia, 250 mg daily for 5 days increases time to exhaustion and lowers the respiratory exchange ratio when compared with taking placebo (19151,26858).
• Hyperlipidemia. It is unclear if oral garcinia is beneficial in patients with hyperlipidemia. Details: A small open-label study of adults with obesity shows that taking garcinia 600 mg twice daily for 3 months may reduce total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides when compared to baseline (111243). The validity of these findings is limited by a lack of a comparator group and blinding.
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral garcinia is beneficial in patients with NAFLD. Details: A small clinical study in females with obesity and NAFLD shows that taking a specific product containing garcinia bark leaf extract (HCA Garcinia Vita Plus, Vitamin House) 312.5 mg daily for 8 weeks in combination with a calorie-restricted diet improves body weight, body mass index (BMI), triglycerides, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol when compared to baseline. However, liver enzyme levels increased slightly (111240). While a calorie-restricted control group was included, a lack of appropriate statistical comparison limits the validity of any between-group findings. Thus, it is unclear if these results are due to garcinia, the calorie-restricted diet, or the combination.
• Obesity. Despite contradictory evidence, oral garcinia seems to produce a very modest weight reduction in some people who are obese or overweight. Details: A meta-analysis of 8 small clinical trials shows that taking garcinia for 8-12 weeks seems to reduce weight by about 1.3 kg and body mass index (BMI) by about 1 kg/m2 when compared with control (104432). This analysis is limited by prominent heterogeneity in the included studies and a lack of sensitivity analyses. Most studies included in the analyses used garcinia 1000-4667 mg (standardized to 50% or 60% hydroxycitric acid) in divided doses daily as non-branded extracts or as specific branded supplements (Super CitriMax, InterHealth Nutraceuticals; Citrin, Sabinsa Corporation) (728,19152,19153,88158,104432). It is unclear which dose, if any, may be most beneficial. More recently, a small, open-label trial in adults with obesity shows that taking garcinia 600 mg twice daily for 3 months reduces body weight and BMI by 1.7 kg and 0.7 kg/m^2 when compared to baseline (111243). The validity of these findings is limited by a lack of a comparator group and blinding. Limited research has also studied garcinia in combination with glucomannan for 6 months, with evidence of moderate benefit for weight loss (96536). More evidence is needed to rate garcinia for these uses.

(Read more about GARCINIA)

POSSIBLY EFFECTIVE

• Hypertension. Oral Hibiscus sabdariffa seems to lower blood pressure by a small amount in patients with mild to moderate hypertension. Details: Most research shows that drinking Hibiscus sabdariffa tea daily can modestly lower blood pressure in patients with pre-hypertension or mild hypertension after 2-6 weeks of treatment (16894,54985,54995,90159,93817,101730,108867). In addition, some research shows that drinking Hibiscus sabdariffa tea daily can modestly lower blood pressure in patients with either untreated or insufficiently treated mild to moderate hypertension (54989,93815,101733,108867). These studies have used tea made from 1.25-10 grams or 150 mg/kg, brewed in 150 mL to 500 mL of water and taken one to three times daily for 2-6 weeks (16894,54985,54989,54995,90159,93815,93817,101730,101733,108867). The dose has been increased to 15 or 20 grams, brewed in 1000 mL for daily consumption for 2-3 weeks if needed (101733,108867). In this population, research shows that drinking Hibiscus sabdariffa tea or infusions is more effective than hydrochlorothiazide 25 mg daily and as effective as captopril 25 mg twice daily for lowering systolic and diastolic blood pressure (54989,93815). Pooled analyses of results from clinical research shows that drinking Hibiscus sabdariffa tea or taking Hibiscus sabdariffa extract lowers systolic blood pressure by 5-8 mmHg and diastolic blood pressure by about 4 mmHg in patients with or without mild hypertension (93817,105304). The clinical relevance of these results is uncertain due to the small size and low quality of the included studies. Some researchers suggest that there is insufficient reliable evidence to determine if the effects of Hibiscus sabdariffa are clinically relevant (17114). Taking Hibiscus sabdariffa in combination with other ingredients has also showed beneficial effects on blood pressure in clinical research. In one study, a specific product containing Hibiscus sabdariffa extract in combination with olive leaf extract (NW Roselle) for 8 weeks was found to be as effective as captopril 25 mg twice daily for reducing systolic and diastolic blood pressure (105302). In another study, a specific product (MetabolAid, Monteloeder S.L.) providing Hibiscus sabdariffa and lemon verbena extracts for 12 weeks reduced systolic, but not diastolic, blood pressure. However, these effects were limited to daytime ambulatory readings (105303).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cancer. Although there has been interest in using oral Hibiscus sabdariffa for cancer, there is insufficient reliable information about the clinical effects of Hibiscus sabdariffa for this condition.
• Constipation. Although there has been interest in using oral Hibiscus sabdariffa for constipation, there is insufficient reliable information about the clinical effects of Hibiscus sabdariffa for this purpose.
• Diabetes. It is unclear if oral Hibiscus sabdariffa is beneficial for diabetes. Details: Pooled analyses of results from clinical research show that taking Hibiscus sabdariffa lowers fasting blood glucose levels by approximately 4 mg/dL (105304,105305). However, only one low-quality study included in one of these analyses examined the effects of Hibiscus sabdariffa on fasting blood glucose levels in patients with type 2 diabetes (105305). Therefore, any benefit specific to this population is unclear.
• Dry mouth. Topical Hibiscus sabdariffa has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with dry mouth shows that taking a specific mucoadhesive tablet (Aqualief, Helsinn Healthcare SA), containing a combination of Hibiscus sabdariffa and carnosine, 400 mg three times daily after meals for 6 days increases saliva production and improves symptoms of dry mouth when compared to baseline. While saliva production was also increased in patients taking placebo, the increase was 3-fold greater with the combination product, and significant improvements in dry mouth symptoms were lacking in the placebo group (103288). It is unclear if these findings are due to Hibiscus sabdariffa, carnosine, or the combination.
• Dry skin. It is unclear if oral Hibiscus sabdariffa is beneficial for dry skin. Details: A crossover clinical study in healthy adults shows that drinking Hibiscus sabdariffa 100 mL twice daily for 6 months improves skin moisture but does not improve skin surface water loss or sebum secretion when compared to baseline (112426). However, it is unclear whether any improvements are clinically significant or apply to patients with dry skin.
• Dyslipidemia. It is unclear if oral Hibiscus sabdariffa is beneficial for dyslipidemia. Details: Some preliminary clinical research shows that drinking Hibiscus sabdariffa tea or taking Hibiscus sabdariffa extract can decrease total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides, and can increase high-density lipoprotein (HDL) cholesterol, in patients with metabolic disorders (54997,54999). These studies used Hibiscus sabdariffa 2 grams in 240 mL boiling water, steeping for 20-30 minutes, twice daily and Hibiscus sabdariffa extract 100 mg daily, each for 4 weeks (54997,54999). Clinical research also shows that taking powdered dried Hibiscus sabdariffa 6 grams daily reduces LDL cholesterol by approximately 8% in obese adolescents with dyslipidemia (93816). Additionally, two meta-analyses shows that taking Hibiscus sabdariffa extract modestly reduces LDL cholesterol levels (105305,105306). However, other preliminary clinical research shows that taking Hibiscus sabdariffa extract does not improve cholesterol or triglyceride levels in patients with hypercholesterolemia (17415,55000). Two pooled analyses of clinical data show that Hibiscus sabdariffa does not improve total cholesterol, HDL cholesterol, LDL cholesterol, or triglycerides when compared with placebo, a change in diet, or black tea in patients with hyperlipidemia, metabolic disorders, or obesity (93805,105304). The differing conclusions of these trials and meta-analyses are related to their inclusion and exclusion criteria with respect to age and populations of focus.
• Kidney stones (nephrolithiasis). Although there has been interest in using oral Hibiscus sabdariffa for kidney stones, there is insufficient reliable information about the clinical effects of Hibiscus sabdariffa for this condition.
• Metabolic syndrome. Some small clinical studies suggest that oral Hibiscus sabdariffa may be beneficial for metabolic syndrome. Details: In adults with metabolic syndrome, a small clinical trial shows that taking Hibiscus sabdariffa powder 500 mg daily for 4 weeks modestly reduces systolic blood pressure and triglyceride levels by 5% and 15%, respectively, when compared with baseline. These changes were significant when compared with placebo. However, there was no effect on diastolic blood pressure, fasting glucose or insulin levels, cholesterol levels, or body mass index (105307). Other preliminary clinical research in adults with metabolic syndrome shows that taking Hibiscus sabdariffa extract 100 mg daily for one month modestly reduces fasting glucose and low-density lipoprotein (LDL) cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels when compared with baseline. When taken in combination with recommendations to follow the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) diet, triglyceride levels and blood pressure were also modestly reduced (54999).
• Obesity. Oral Hibiscus sabdariffa has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Two small clinical trials in overweight and obese females show that taking a combination product (MetabolAid, Monteloeder SL) containing Hibiscus sabdariffa and lemon verbena extracts as 500 mg per capsule daily for 2 months modestly increases weight loss when compared with placebo (97290,101731). This combination also reduces hunger and increases satiety, and has small to moderate beneficial effects on low-density lipoprotein (LDL) cholesterol, heart rate, and blood pressure (97290). The effects in obese individuals seem to be less than those seen in overweight individuals, with no overall change in abdominal circumference or percent body fat in obese individuals (101731). A meta-analysis of these two studies and several others in overweight or obese individuals shows that taking Hibiscus sabdariffa in combination with other ingredients daily for 6-12 weeks modestly improves body mass index, weight, and body fat percentage when compared with control (112427). However, the validity of these results is limited by the heterogeneity of the included studies. Additionally, it is unknown if these effects are due to Hibiscus sabdariffa, other ingredients, or the combination.
• Urinary tract infections (UTIs). It is unclear if oral Hibiscus sabdariffa is beneficial for UTIs. Details: Population research in patients with urinary catheters living in long-term care facilities has found that drinking Hibiscus sabdariffa tea is associated with a 36% lower risk of UTIs when compared with not drinking tea (93807). Some small clinical studies that have evaluated the use of Hibiscus sabdariffa in combination with other ingredients suggest that they might reduce the occurrence of symptomatic UTIs in females with recurrent UTIs. One study used a product containing Hibiscus sabdariffa 200 mg, D-mannose 1000 mg, and Lactobacillus plantarum Lp-115 (1 billion colony forming units) daily for 15 days each month for 6 months (101734); the other study used a specific product (Monurelle Plus, Zambon Italia) containing Hibiscus sabdariffa 100 mg, xyloglucan 100 mg, gelatin 50 mg, and propolis 100 mg twice daily for 14 days (101735). Also, a small observational study in patients with an uncomplicated UTI has found that taking two tablets of a specific combination product (Acidif plus) containing Hibiscus sabdariffa extract 100 mg, boswellia gummy dry extract 100 mg, and L-methionine 400 mg daily for 7 days is associated with reduced UTI symptoms and reduced bacteriuria when compared with taking an unreported dose of fosfomycin for two days (103783). However, due to the poor quality of these studies, the magnitude of benefit is unclear. Also, it is unknown whether these effects are due to Hibiscus sabdariffa, other ingredients, or the combination.
• Wound healing. Although there has been interest in using topical Hibiscus sabdariffa for wound healing, there is insufficient reliable information about the clinical effects of Hibiscus sabdariffa for this purpose.

  More evidence is needed to rate Hibiscus sabdariffa for these uses.

(Read more about HIBISCUS SABDARIFFA)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Obesity. Clinical evidence shows that drinking a raspberry-flavored yogurt drink containing hoodia purified extract 1110 mg twice daily for 15 days does not reduce energy intake or body weight compared to placebo in overweight women (18052). More evidence is needed to rate hoodia for this use.

(Read more about HOODIA)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Androgenic alopecia. Although there is interest in using oral horsetail for alopecia, there is insufficient reliable information about the clinical effects of horsetail for this condition.
• Hypertension. Oral horsetail seems to reduce blood pressure in patients with hypertension. Details: A clinical trial in patients with stage 1 systemic arterial hypertension shows that taking horsetail extract 900 mg daily for 3 months decreases systolic and diastolic blood pressure by 13 mmHg and 8 mmHg, respectively, and is similarly effective to hydrochlorothiazide 25 mg daily (108849). The validity of this finding is limited due to high withdrawal rates and low adherence to treatment protocols.
• Kidney stones (nephrolithiasis). Although there is interest in using oral horsetail for kidney stones, there is insufficient reliable information about the clinical effects of horsetail for this condition.
• Obesity. Although there is interest in using oral horsetail for weight loss, there is insufficient reliable information about the clinical effects of horsetail for this purpose.
• Osteoporosis. It is unclear if oral horsetail is beneficial for osteoporosis. Details: Preliminary clinical research shows that taking two tablets of either dried horsetail extract or a specific combination of horsetail extract with calcium (Osteosil Calcium) daily for 2-month intervals separated by 2 weeks of no treatment for up to one year can increase bone density when compared with no treatment in postmenopausal patients with osteoporosis. The effect of horsetail extract plus calcium (Osteosil Calcium) seems to be greater than the effect of dried horsetail extract alone (55578).
• Tonsillitis. Oral horsetail has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in children with acute non-bacterial tonsillitis shows that taking a specific combination product (Imupret) for 10 days in addition to standard symptomatic therapy accelerates recovery by a small amount when compared with symptomatic therapy alone. Overall treatment response after 10 days occurred in 82% of patients taking the combination product compared with 65% of patients receiving symptomatic therapy alone. Withdrawal from antipyretic drugs occurred approximately one day earlier in children using the horsetail product. Per 100 grams, Imupret provides 29 grams of an alcoholic extract produced from horsetail 0.5 grams, marshmallow root 0.4 grams, chamomile flowers 0.3 grams, walnut leaves 0.4 grams, English walnut leaves 0.4 grams, yarrow 0.4 grams, oak bark 0.2 grams, and dandelion 0.4 grams. In children aged 6-11 years, 15 drops 6 times daily for 5 days and then 15 drops 3 times daily for 5 days was used. In children aged 12-18 years, 25 drops 6 times daily for 10 days was used. (100347). Due to the small difference between the two groups and the open-label design, the clinical relevance of this study is unclear. Also, it is unclear if these benefits are due to horsetail, the other ingredients, or the combination.
• Urinary incontinence. Oral horsetail 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 supplement (Urox, Seipel Group) 840 mg, containing a combination of horsetail stem, three-leaf caper, and lindera root daily with food for 8 weeks modestly decreases urinary frequency, stress incontinence, and urgency incontinence when compared with placebo in patients with urinary incontinence and/or overactive bladder (97575). It is unclear if these effects are due to horsetail, the other ingredients, or the combination.
• Urinary tract infections (UTIs). Although there is interest in using oral horsetail for UTIs, there is insufficient reliable information about the clinical effects of horsetail for this condition. More evidence is needed to rate horsetail for these uses.

(Read more about HORSETAIL)

EFFECTIVE

• L-carnitine deficiency. Oral and intravenous L-carnitine can treat primary and secondary L-carnitine deficiency. Details: Administering L-carnitine orally or intravenously is effective for acute or chronic treatment of primary L-carnitine deficiency or secondary L-carnitine deficiency due to inborn errors of metabolism. This is an FDA-approved indication for L-carnitine (4949,58611,59018). For primary or secondary deficiencies, oral L-carnitine 990 mg 2-3 times daily is used. For inborn errors of metabolism resulting in secondary L-carnitine deficiency, L-carnitine 50 mg/kg given as a slow (2-3 minute) bolus injection or by infusion followed by 50 mg/kg administered in divided doses every 3-4 hours over the next 24 hours is also used. Subsequent daily maintenance doses of intravenous L-carnitine are usually around 50 mg/kg (3616).

POSSIBLY EFFECTIVE

• Angina. Oral and intravenous L-carnitine may improve exercise tolerance and symptoms of angina during exercise in patients with angina. Details: Several small clinical trials in patients with chronic stable angina or cardiac syndrome X show that taking L-carnitine orally or intravenously seems to improve exercise tolerance and time to onset of angina when compared with placebo (3623,3624,58156,59096,59118,59216,59217,59230). Oral doses of L-carnitine have ranged from 900 mg to 2 grams daily in single or divided doses for 2 weeks to 6 months (3623,3624,58156,59096,59118,59217). Intravenous L-carnitine 3 grams in 500 mL of 5% dextrose, administered once daily for 14 days (59230), or intravenous DL-carnitine 40 mg/kg administered 30 minutes prior to exercise (59216) have also been used.
• Congestive heart failure (CHF). Oral and intravenous L-carnitine may improve exercise capacity and symptoms of heart failure in patients with CHF. Details: Several small clinical trials in patients with CHF show that taking L-carnitine 1.5-3 grams daily in single or divided doses for up to 34 months or administering intravenous L-carnitine 5 grams daily for 7 days seems to improve symptoms and increase exercise capacity when compared with placebo (3625,3626,58145,58771,58824). Also, taking a specific combination product containing L-carnitine 2250 mg and coenzyme Q10 270 mg (Carni Q-Gel, Tishcon Corporation) daily for 12 weeks appears to improve symptoms of CHF when compared with no treatment (58392).
• Hyperlipidemia. Oral or intravenous L-carnitine may slightly improve lipid levels. Oral, but not intravenous, L-carnitine may also improve lipoprotein(a) levels in patients with elevated lipoprotein(a). Details: Most meta-analyses of clinical research in patients with or without hyperlipidemia show that L-carnitine, given orally at a dose of 76 mg to 3 grams daily or intravenously at a dose of 15-20 mg/kg three times weekly, appears to reduce total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels by up to 9.5 mg/dL, 8.3 mg/dL, and 11.2 mg/dL, respectively, while increasing high-density lipoprotein (HDL) cholesterol by up to 1.6 mg/dL. Sub-analyses in patients with elevated levels of specific lipids shows that L-carnitine might be most beneficial in these populations (95073,102019,111886). However, clinical research is generally very low to moderate quality. Also, any effects of L-carnitine on these lipids are modest and might not be considered clinically significant. An umbrella meta-analysis of meta-analyses of clinical research shows that taking L-carnitine orally reduces total cholesterol, LDL cholesterol, and triglyceride levels by only 1.1 mg/dL, 4.8 mg/dL, and 2.5 mg/dL, with increases in HDL cholesterol of 0.7 mg/dL (111896). More information is needed on the effects of L-carnitine on lipid levels specifically in patients with hyperlipidemia. Some research has also evaluated the benefits of L-carnitine in people with hyperlipidemia and elevated lipoprotein(a) levels or those undergoing hemodialysis. Preliminary clinical research and a meta-analysis of clinical research in these populations shows that taking L-carnitine 1-2 grams daily for 8-24 weeks reduces levels of lipoprotein(a) by about 9 mg/dL when compared with control (58155,95073). However, giving L-carnitine intravenously 1 gram three times weekly or 4 grams daily does not improve lipoprotein(a) levels in these patients (95073). Also, oral or intravenous L-carnitine does not improve LDL cholesterol, HDL cholesterol, or triglyceride levels in these patients (58155,95073). Whether L-carnitine reduces the risk of cardiovascular events in patients with hyperlipidemia is unknown.
• Kidney failure. Intravenous, but not oral, L-carnitine is FDA-approved for the prevention and treatment of L-carnitine deficiency in patients with kidney failure undergoing hemodialysis. Any other benefits with the use of L-carnitine in patients on hemodialysis are unclear. Details: Patients with kidney failure undergoing maintenance hemodialysis often experience L-carnitine deficiency, which can lead to lipid, red blood cell, cardiac muscle, and skeletal muscle abnormalities (26496). Use of intravenous L-carnitine for the prevention and treatment of L-carnitine deficiency in people with kidney failure who are undergoing hemodialysis is an FDA-approved indication for L-carnitine. L-carnitine 10-20 mg/kg is given as a slow (2-3 minute) bolus injection, with dose adjustments made based on subsequent pre-dialysis L-carnitine concentrations (3616). However, oral L-carnitine is not FDA-approved for this purpose. There is concern that long-term administration of high doses of oral L-carnitine may result in accumulation of toxic metabolites, including trimethylamine and trimethylamine-N-oxide, in patients with kidney failure (3616). Research in other areas are conflicting. Most clinical research shows that taking L-carnitine 0.7-3 grams or 10 mg/kg daily or administering L-carnitine 2-6 grams or 30-60 mg/kg weekly via intravenous infusion can improve cardiac function, intravenous fistula complications, red blood cell count, hemoglobin, and C-reactive protein levels in patients on hemodialysis (9790,26496,58257,58437,58842,59009,59178,111877). A meta-analysis of 18 clinical studies in adults with kidney-related anemia undergoing hemodialysis shows that receiving oral or intravenous L-carnitine reduces erythropoietin responsiveness and erythropoiesis stimulating agent (ESA) requirement, but not hemoglobin level, when compared with placebo or conventional therapy, regardless of treatment duration or route of administration (107406). Despite an earlier meta-analysis suggesting that L-carnitine does not reduce the incidence of dialysis-related hypotension or muscle cramping (58511), a more recent meta-analysis shows that L-carnitine reduces the incidence of dialysis-related hypotension by 74% when compared with placebo (111878). However, sub-analyses suggest that only oral L-carnitine, and doses of over 4.2 grams weekly for at least 12 weeks, are effective for preventing hypotension (111878). A meta-analysis and some preliminary clinical research also show that muscle cramping is reduced by up to 78% when compared with controls (104176,111878). Additionally, observational research has found that administering at least 1 gram of L-carnitine per dialysis session for at least 10 sessions monthly is associated with a 10% to 20% decrease in the number of hospitalization days during the subsequent month (58409). However, L-carnitine may not be beneficial for improving other measures in people with kidney failure receiving dialysis. While some research shows that L-carnitine decreases lipoprotein(a) levels (44187), low-density lipoprotein (LDL) cholesterol levels (26496,91723,107399), and total cholesterol levels (107399), most research shows that it does not improve serum lipid levels (9790,26496,44187,58257,58320,58842,58939,59009,59025,59031)(59036,59059,59080,90633,91723,107399). Additionally, while one small clinical trial shows that taking L-carnitine can improve performance on some exercise tests (104179), most research shows that L-carnitine does not improve respiratory function or exercise performance. The effect on quality of life is unclear (58154,58437,58472,58743,59031,90633,111867,111877).
• Male infertility. Oral L-carnitine, taken alone or in combination with acetyl-L-carnitine, may increase sperm motility in males with infertility, leading to a greater likelihood of pregnancy in female partners. Details: Although some clinical research has yielded conflicting results (58209,58588,59020,90627,111861), most clinical research shows that taking L-carnitine 1-3 grams daily in divided doses for up to 24 weeks, with or without acetyl-L-carnitine 1 gram daily, increases sperm count and motility, and improves sperm morphology, in males with infertility of various etiologies (12352,58167,58182,58194,58334,58469,58831,58849,59129,59189)(59190,101560,107394,111861,111459,111888,111890). However, it is unclear if taking L-carnitine increases the odds of pregnancy. One meta-analysis of randomized controlled trials shows that taking L-carnitine and acetyl-L-carnitine in combination increases the odds of pregnancy by 3.7-fold over placebo. However most clinical research investigating the effect of L-carnitine alone or with acetyl L-carnitine on pregnancy rates disagrees (12352,58182,101560,111861,111459,111888). The number of studies investigating the effect of L-carnitine alone or with acetyl-L-carnitine on pregnancy rate is small and the duration of supplementation may be inadequate. Taking L-carnitine 1 gram and acetyl-L-carnitine 0.5 grams twice daily after taking nonsteroidal anti-inflammatory drugs for 2 months seems to increase sperm count and motility in males with abacterial prostatovesiculoepididymitis, an inflammation of the prostate gland, seminal vesicles, and epididymis (9791). Some studies have also evaluated L-carnitine in combination with other ingredients. One clinical trial in males with asthenospermia shows that taking L-carnitine 150 mg, acetyl-L-carnitine 50 mg, L-arginine 1660 mg, and Panax ginseng 200 mg daily for 3 months increases sperm motility and sexual satisfaction when compared with no treatment (32189). Another small clinical trial shows that taking this combination along with prulifloxacin 600 mg daily for 6 months improves sperm concentration and motility when compared with prulifloxacin alone in patients with chronic prostatitis due to Chlamydia trachomatis infection (59006). Other small and preliminary clinical studies have investigated the effects of a specific combination product providing L-carnitine 1 gram twice daily for 6 months, along with acetyl-L-carnitine, coenzyme Q10, selenium, zinc, vitamin C, folic acid, vitamin B12, and citric acid (Proxeed Plus). Taking this combination product has been shown to improve measures of sperm quality such as sperm count, sperm concentration, total motility, and progressive motility when compared to baseline. The effect on sperm volume and morphology is unclear. Most research has been conducted in patients with oligoasthenozoospermia, although some benefit has also been shown in patients with varicocele-related infertility, especially those with more severe varicocele (102017,107395,111296). The validity of these findings is limited by the lack of comparator group. Also, it is unclear if these effects are due to L-carnitine, other ingredients, or the combination. The effect of L-carnitine in combination with other ingredients on pregnancy rate has also been examined. One meta-analysis of moderate-quality clinical research shows that taking L-carnitine in combination with micronutrients increases the odds of pregnancy by 3.5-fold over placebo or no treatment (111888).
• Myocarditis. Oral DL-carnitine may prevent myocarditis in children with diphtheria. Details: Myocarditis is a complication of diphtheria. Clinical research in children with diphtheria shows that taking DL-carnitine 100 mg/kg daily for 4 days reduces the risk of myocarditis and mortality when compared with no treatment (3620,3621).
• Valproic acid-induced toxicities. Although more well-designed research is needed to confirm these findings, oral and intravenous L-carnitine may improve neurologic and hepatic function and reduce ammonia levels in patients with these valproic acid-induced toxicities. Details: Valproic acid-induced toxicities are often associated with low plasma and tissue levels of L-carnitine. Preliminary clinical research and case reports in patients on valproic acid therapy who have neurologic or hepatic deterioration or hyperammonemia show that taking L-carnitine 50-100 mg/kg daily in divided doses or administering L-carnitine 150-500 mg/kg daily via intravenous infusion seems to improve neurologic and hepatic function and bring plasma ammonia levels within normal limits (1438,1914,1915,1916,1917,4523,5798,5799,95068). There is also some preliminary evidence that intravenous L-carnitine can prevent the development of severe valproic acid-induced hepatotoxicity when given to patients being treated for overdose and accidental ingestion of valproic acid (1438,4528,5798,5799), especially if treatment is initiated early (4528). Despite these results, most evidence consists of anecdotal individuals or small case series. A more recent retrospective cohort study suggests that treatment with an L-carnitine dosing regimen consisting of a 100 mg/kg intravenous loading dose followed by up to 3 grams daily in divided doses for 3 days or until ICU discharge does not enhance valproic acid elimination or prevent organ dysfunction when compared with patients not treated with L-carnitine (111869). Also, taking L-carnitine does not appear to reduce valproic acid-associated weight gain (58295). Well-designed clinical trials are still needed to determine the role of L-carnitine in the treatment or prevention of valproic acid toxicities.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Topical L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small clinical trial in patients with mild-to-moderate acne shows that applying a proprietary formulation containing L-carnitine, licochalcone, and 1,2-decanediol to the face twice daily for 8 weeks reduces the number of acne lesions and pustules and improves quality of life when compared to baseline. However, the improvements do not appear to be significant when compared with placebo (26493).
• Age-related fatigue. Small clinical studies suggest that oral L-carnitine may improve physical and mental fatigue associated with aging. Details: Two small clinical trials in elderly patients experiencing fatigue after slight physical activity shows that taking L-carnitine 2-4 grams daily for 1-6 months improves physical and mental fatigue, increases muscle mass, and decreases fat mass when compared with placebo (16109,16111).
• Aluminum phosphide poisoning. It is unclear if intravenous L-carnitine is beneficial in people with aluminum phosphide poisoning. Details: A meta-analysis of preliminary clinical research in patients with aluminum phosphide poisoning shows that intravenous L-carnitine does not reduce the odds of mortality when compared with control groups receiving routine treatments only (111892). However, only 2 studies were included in the analysis and both studies may have been underpowered to detect differences.
• Alzheimer disease. Oral L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with mild to moderate Alzheimer disease shows that taking L-carnitine tartrate 3.73 grams, in combination with serine, nicotinamide riboside, and N-acetyl cysteine, daily for 28 days and then twice daily for 56 days does not improve cognitive function when compared with taking placebo. However, in patients with the most severe symptoms, there was some modest improvement (110623). This study may have been underpowered to detect differences. Also, the effect of L-carnitine alone is unclear.
• Androgenic alopecia. It is unclear if topical L-carnitine is beneficial in people with androgenic alopecia. Details: One small clinical trial in individuals with androgenic alopecia shows that applying topical L-carnitine 2% solution to the scalp twice daily for 6 months significantly increases the number of terminal hair shafts on the scalp when compared with placebo (58390).
• Anorexia nervosa. Although there has been interest in using oral L-carnitine for anorexia nervosa, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Anthracycline cardiotoxicity. Oral and intravenous L-carnitine have only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients with breast cancer undergoing doxorubicin treatment shows that taking a combination of L-carnitine and vitamin E over 4 21-day treatment cycles decreases the proportion of patients with cardiac events by 24.2% when compared with chemotherapy treatment only. There were also modest beneficial effects on some enzyme measures of cardiac health. Patients received L-carnitine 3 grams intravenously on the first day of each cycle followed by an oral intake of 300 mg 4 times daily for the remaining 20 days. Vitamin E 1800 mg daily was taken orally in 3 divided doses (111891).
• Athletic performance. Oral L-carnitine has been evaluated for its effect on athletic performance in several small and short-term clinical studies, with mixed results. Details: Maximal exercise in trained athletes has been associated with a decrease in plasma L-carnitine levels (3648,58583). Theoretically, restoring these levels with L-carnitine supplementation might have beneficial effects. However, clinical studies examining the use of L-carnitine for athletic performance have reported conflicting results. Some clinical studies show that taking L-carnitine 2 grams, either before exercise or daily for up to 6 weeks, enhances athletic performance and endurance and reduces post-exercise muscle pain in male athletes and healthy untrained males (58450,59182,59185), but other studies do not support these findings (1947,59128,59134). Additionally, although some studies show that taking L-carnitine 1-2 grams or 40 mg/kg before exercise or 4 grams daily for 2 weeks can decrease lactate accumulation and increase oxygen uptake, power output, and time to anabolic threshold during exercise (3649,3650,59061,59184,59186), other studies show no improvement in these outcomes (58471,58775,59033,59045,59069,59128). These discrepancies may be related to the small study sizes, short treatment durations, and variable dosing regimens.
• Atrial fibrillation. It is unclear if oral L-carnitine is beneficial for preventing postoperative atrial fibrillation in patients undergoing aortic valve surgery. Details: A very small clinical study in patients undergoing aortic valve replacement or valve-sparing aortic root replacement shows that receiving oral L-carnitine (L-Cartin FF, Otsuka Pharmaceutical) 1 gram three times daily, beginning 2 days prior to surgery and continuing for 7 days after surgery, is associated with a postoperative atrial fibrillation rate of 20%, compared with a rate of 60% in a historical age-matched control group not receiving L-carnitine (107408).
• Attention deficit-hyperactivity disorder (ADHD). It is unclear if oral L-carnitine is beneficial in children with ADHD. Details: One small crossover trial in children with ADHD shows that taking L-carnitine 50 mg/kg twice daily for 6 months improves parent and teacher assessments of behavior when compared with placebo (58166).
• Autism spectrum disorder. Small clinical studies suggest that oral L-carnitine may improve some symptoms of autism spectrum disorder. Details: Small clinical trials in children 3-16 years of age with autism spectrum disorder show that taking L-carnitine 50 mg/kg or 150 mg/kg daily for 8 to 12 weeks modestly improves overall symptoms of autism, especially lethargy, social isolation, hyperactivity, and irritability, when compared with taking placebo. However, there is inconsistency between studies with respect to rating scales used and specific endpoints showing improvement. In one study, children remained on any pre-existing medications; in the other two, all children were also taking risperidone (58981,111887,111900).
• Arrhythmia. Small clinical studies suggest that oral L-carnitine may reduce the incidence of arrhythmias in patients with premature ventricular contractions. Details: Small clinical trials in patients with premature ventricular contractions show that taking L-carnitine 2 grams twice daily for 45 weeks or 2 grams three times daily for 2 weeks might reduce the incidence of arrhythmias when compared to baseline (59043,59120,59143).
• Asthenopia (eye strain). Oral L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in videoterminal users with computer vision syndrome and without dry eye shows that taking a product containing L-carnitine 50 mg, along with zinc and extracts of elderberry, black currant, and eleuthero root (Meramirt CM) daily for 1 month modestly reduces severity of eye strain and sensitivity when compared with not taking this product (111295). It is unclear if these findings are due to L-carnitine, other ingredients, or the combination.
• Benign prostatic hyperplasia (BPH). Oral L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients in Iran with BPH shows that taking L-carnitine 1000 mg plus coenzyme Q10 daily in addition to finasteride 5 mg daily for 8 weeks modestly improves subjective assessment of sexual function when compared with placebo plus finasteride. There was no effect on prostate symptoms, prostate specific antigen levels, or quality of life (113226). It is unclear if these effects are due to L-carnitine, coenzyme Q10, or the combination.
• Beta-thalassemia. Small clinical studies suggest that oral L-carnitine may improve symptoms and reduce complications of beta-thalassemia minor, intermedia, and major. Details: Several small clinical trials in children with beta-thalassemia major show that taking L-carnitine 50 mg/kg daily for 3-6 months might reduce pulmonary artery systolic pressure, increase cardiac output during exercise, and improve progression to puberty (58294,58502,58556). Clinical research in adults with beta-thalassemia intermedia shows that taking L-carnitine with hydroxyurea appears to increase hemoglobin and hematocrit and reduce left ventricular end-diastolic diameter, a measure of pulmonary hypertension (58679). In patients with beta-thalassemia major or intermedia aged 6 years and up, taking L-carnitine 50 mg/kg daily for 6 months normalized left ventricular dilatation and hypertrophy in 30% and 37% of patients, respectively, compared with only 10% in those taking placebo. Cardiac output was also improved, but there were no changes in blood parameters (101565). Clinical research in children with beta-thalassemia minor shows that taking L-carnitine 50 mg/kg daily, with or without folic acid 1 mg daily, for 3 months appears to reduce bone pain by 84% to 87% and increase the number of climbable stairs 3.1- to 5.2-fold when compared with baseline (90631).
• Cachexia. Small clinical studies suggest that oral L-carnitine may improve body composition and quality of life in patients with cancer-related cachexia. Details: One small clinical trial in patients with cancer-related cachexia shows that taking L-carnitine 4 grams daily for 12 weeks increases body mass index (BMI) when compared with placebo (59029). Other research shows that taking L-carnitine 4 grams daily with megestrol acetate, eicosapentaenoic acid (EPA), and thalidomide for 5 months is more effective than any single product alone for increasing lean body mass in patients with cancer-related cachexia (23437). Additionally, taking L-carnitine 4 grams daily with megestrol acetate, celecoxib, and antioxidants for 4 months appears more effective than megestrol acetate alone for improving lean body mass, fatigue, and quality of life in these patients (59012).
• Cancer-related fatigue. It is unclear if oral L-carnitine is beneficial for improving fatigue in patients with advanced cancer. Details: Some cancer patients have low blood levels of L-carnitine, which may reduce energy production and lead to fatigue. Some small clinical trials in patients with advanced cancer show that taking L-carnitine 3-4 grams daily for 7 days significantly improves some measures of fatigue when compared to baseline (16106,16110). However, other higher quality clinical research shows that taking L-carnitine 2-4 grams daily for 4-12 weeks is no more effective than placebo for improving fatigue in advanced cancer patients (26498,58523,59029).
• Celiac disease. It is unclear if oral L-carnitine is beneficial in patients with celiac disease. Details: Some research shows that L-carnitine blood levels are low in patients with celiac disease. One small clinical trial in patients with celiac disease shows that taking L-carnitine 2 grams daily for 6 months lowers some measures of fatigue when compared with placebo. However, L-carnitine does not significantly improve measures of depression or quality of life in these patients (16105).
• Chemotherapy-related fatigue. It is unclear if oral L-carnitine is beneficial in patients with fatigue due to sunitinib therapy. Details: A small clinical study in adults with renal cell carcinoma who are experiencing fatigue associated with sunitinib treatment shows that taking L-carnitine 1500 mg daily for 2 weeks modestly improves fatigue severity when compared to baseline (100352). The validity of this finding is limited by the small study size and lack of a comparator group.
• Chronic fatigue syndrome (CFS). It is unclear if oral L-carnitine is beneficial in patients with CFS. Details: One small clinical study in adults with CFS shows that taking L-carnitine 1 gram three times daily for 2 months can improve some symptoms of CFS when compared to baseline (3630). The validity of this finding is limited by the lack of a comparator group.
• Chronic obstructive pulmonary disease (COPD). It is unclear if oral L-carnitine is beneficial in patients with COPD. Details: One small clinical study in adults with moderate to severe COPD shows that taking L-carnitine 2 grams daily for 6 weeks improves exercise performance and walking tolerance when compared with placebo (58213).
• Cirrhosis. Preliminary research suggests that oral L-carnitine may be beneficial in patients with cirrhosis. Details: One small clinical trial in patients with cirrhosis who are receiving branched-chain amino acids supplements to improve nutritional status shows that taking L-carnitine 1 gram orally daily for 6 months, in addition to increasing exercise by 2000 steps per day, does not improve muscle volume, handgrip strength, or leg strength, but does reduce complaints of muscle cramping, when compared to baseline (102124). Another small, uncontrolled clinical trial in patients with cirrhosis shows that taking L-carnitine 1800 mg daily for 6 months does not improve Child-Pugh scores, but may improve quality of life, when compared to baseline (104177). The validity of these studies is limited by the lack of comparator groups. The effect of L-carnitine has also been examined retrospectively in patients with cirrhosis. One retrospective study in matched patients that had been admitted to hospital for cirrhosis suggests that taking L-carnitine for more than 30 days is associated with an increase in survival length by about 21 months compared with not taking L-carnitine. Overall, L-carnitine use was also associated with a 36% to 48% increase in the proportion of patients surviving 1-5 years, with the greatest effect in patients with modest to severe liver dysfunction. The median dose of L-carnitine was 1000 mg daily for at least 6 months is associated with a reduced loss of skeletal muscle compared with not taking L-carnitine (111860). The validity of these studies is limited by their retrospective design.
• Cognitive function. It is unclear if oral L-carnitine is beneficial for improving cognitive function in healthy individuals. Details: Low-quality clinical research shows that taking L-carnitine 500 mg as a single dose or 250 mg twice daily for 3 days does not improve cognitive function or memory in otherwise healthy young adults when compared with placebo (58176,95070).
• Coronary heart disease (CHD). It is unclear if oral L-carnitine is beneficial in patients with CHD. Details: One small clinical trial in patients with CHD shows that taking L-carnitine 2 grams prior to exercise does not improve endurance when compared with placebo (58196). Another small clinical trial in patients with CHD shows that taking L-carnitine 1 gram daily for 12 weeks does not improve low-density lipoprotein (LDL) cholesterol, total cholesterol, or apolipoprotein-B when compared with placebo; however, it does appear to increase high-density lipoprotein (HDL) and apolipoprotein A-1 levels in these patients (95071).
• Coronavirus disease 2019 (COVID-19). It is unclear if oral L-carnitine is beneficial for COVID-19 prevention or treatment. Details: Preliminary clinical research in patients hospitalized with mild to moderate COVID-19 shows that taking L-carnitine 1 gram 3 times daily for 5 days does not reduce the incidence of fever or cough when compared with standard treatments only. However, all patients taking L-carnitine survived compared with 86% of those given standard treatment only. Also, there were improvements in oxygen saturation and inflammatory measures (111874). Other clinical research in patients with confirmed asymptomatic or mild COVID-19 shows that taking L-carnitine tartrate (Carnipure) 1 gram 3 times daily for 21 days does not prevent the development of severe lung symptoms when compared with taking placebo. However, in a sub-group of patients, lung lesion improvement was significantly better between days 7 and 14. In adults without COVID-19 but living with someone with confirmed disease, taking this product does not prevent COVID-19 when compared with taking placebo. However, the total number of confirmed illnesses in the population was low (111898).
• Critical illness (trauma). It is unclear if oral or nasogastric L-carnitine is beneficial for critical illness. Details: One small clinical trial in critically ill patients in the ICU shows that receiving L-carnitine (BSK, Zist Takhmir Co, Tehran-Iran) 3 grams daily via a nasogastric tube for 7 days modestly improves disease severity, organ function, inflammatory and other laboratory measures when compared with receiving placebo. Also, mortality rate was reduced by approximately 50%. There was no effect on the duration of hospital or ICU stay (111883,111884). However, another small clinical trial in critically ill patients following an acute ischemic stroke shows that oral or nasogastric L-carnitine tartrate 500 mg every 8 hours for 6 days does not affect the duration of mechanical ventilation or hospital or ICU stay, the severity of illness, or 28-day mortality rates, when compared with taking placebo. There was a modest beneficial effect on insulin resistance (111881). This study was small and may have been underpowered to detect differences.
• Diabetes. Oral L-carnitine may improve glycemic control in patients with diabetes, but it is unclear if these improvements are clinically meaningful. It is also unclear if L-carnitine can improve lipid profiles or weight loss in these patients. Details: While individual study results are mixed (58169,58189,58514,58793,90632,96922,101561), meta-analyses of available clinical research in mixed populations shows that taking L-carnitine 200 mg to 4 grams daily reduces fasting plasma glucose and glycated hemoglobin (HbA1C) levels, and possibly insulin, and improves insulin resistance, when compared with taking placebo or a control diet, although the clinical significance of these improvements is unclear (102018,111875,111886). One meta-analysis shows that these benefits are generally specific to patients with high levels of fasting glucose, diabetes, or obesity, as well as studies investigating L-carnitine in doses of at least 2 grams daily for 12 weeks. However, a small number of studies included in this analysis investigated the effects of acetyl-L-carnitine (111875). Other research in obese patients with type 2 diabetes shows that, when taken with orlistat or sibutramine, L-carnitine 2 grams daily for 12 months decreases body weight and body mass index and improves glycemic control when compared with orlistat or sibutramine alone (58778,58830,58882). The effect of L-carnitine on lipids in people with diabetes is unclear. Some studies show significant reductions in total cholesterol, low-density lipoprotein cholesterol, triglycerides, and/or lipoprotein(a) (58554,58647,58649,90632,101561,107397), while other studies show no improvement in lipid profiles (58169,58189).
• Dilated cardiomyopathy. Small clinical studies suggest that oral L-carnitine may improve ejection fraction in children with dilated cardiomyopathy and adults with ischemic cardiomyopathy. Details: Primary L-carnitine deficiency is a common cause of pediatric dilated cardiomyopathy. Additionally, patients with dilated cardiomyopathy of unknown etiology have been shown to have low cardiac levels of L-carnitine (59196,100351). Due to these findings, L-carnitine has been evaluated for the treatment of dilated cardiomyopathy in children and adults, but the small sizes of these studies and methodological limitations limit the reliability of the results. One small clinical study in children under 13 years of age with dilated cardiomyopathy shows that taking L-carnitine 50-100 mg/kg daily for 1 year in conjunction with standard care improves ejection fraction and reduces left atrial and ventricular diameters when compared with placebo and standard care (100351). The results of this study are limited by the small sample size, unclear etiology of dilated cardiomyopathy, and potential bias. Another small clinical study in children under 5 years of age with dilated cardiomyopathy and low serum levels of L-carnitine shows that taking L-carnitine 100 mg/kg daily for 3 months improves left ventricular ejection fraction (LVEF), cardiac output, and New York Heart Association (NYHA) classification when compared with baseline (59196). Further research is needed to clarify whether L-carnitine is beneficial for most children with dilated cardiomyopathy, or only those with carnitine deficiency. L-carnitine has also been evaluated in older adults. A meta-analysis of clinical studies in mostly older adults with dilated cardiomyopathy shows that addition of intravenous L-carnitine, alone or followed by oral L-carnitine, 1-6 grams daily to conventional therapy for a total of 10-28 days is associated with a 28% increased likelihood of overall efficacy, with improvements observed in both LVEF and cardiac output, when compared with conventional therapy alone (107405). The validity of these findings is limited by the heterogeneity of the included studies, potential publication bias, and unclear reporting. A small individual clinical study in older adults with ischemic cardiomyopathy shows that taking oral L-carnitine daily for 2 months improves LVEF when compared with baseline (58150). The validity of this finding is limited by the lack of a comparator group.
• Dry eye. Topical L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Evidence suggests that chronic use of eye drops containing benzalkonium chloride can cause tear film instability and lead to dry eye (90921). One small clinical trial in patients with glaucoma using eye drops containing benzalkonium chloride shows that using additional eye drops containing L-carnitine (1.017%), eledoisin (0.04%), taurine (0.49%), sodium hyaluronate (0.20 grams/100 mL), and vitamin E acetate (0.20 grams/100 mL) (Carnidrop Plus, Sigma-Tau) three times daily for 15 days reduces dry eye symptoms by approximately 50% when compared to baseline (90625). It is unclear if these findings are due to L-carnitine, other ingredients, or the combination.
• Endometriosis. Although there has been interest in using oral L-carnitine for endometriosis, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Exercise-induced muscle damage. It is unclear if oral L-carnitine tartrate is beneficial for exercise recovery. Details: A small clinical study in healthy males and females participating in moderate physical activity at least 3 days weekly shows that taking a specific product (Carnipure, Lonza Consumer Health, Inc.) providing elemental L-carnitine 2 grams daily for 5 weeks improves perceived recovery and soreness as well as serum creatine kinase levels by 33% and 28%, respectively, when compared with placebo (107398).
• Exercise-induced muscle soreness. Small clinical studies suggest that oral L-carnitine may slightly reduce exercise-induced muscle soreness. Details: Evidence from mostly small clinical trials, when considered alone or combined via meta-analysis, shows that taking L-carnitine 1-3 grams daily for around 3 weeks modestly reduces exercise-induced muscle soreness, especially in the period of 24-48 hours after exercise. Benefits may last up to 96 hours post-exercise. Levels of creatinine kinase, lactate dehydrogenase, and myoglobin also appear to improve with L-carnitine supplementation, reflecting a reduction in muscle damage (58326,58709,59148,101567).
• Hepatic encephalopathy. Oral or intravenous L-carnitine may improve biochemical markers of disease severity in patients with hepatic encephalopathy, but L-carnitine does not seem to improve clinically important outcomes such as fatigue, quality of life, or overall disease severity. Details: A meta-analysis of nine studies in adults with hepatic encephalopathy shows that taking L-carnitine 1-6 grams daily orally or intravenously for up to 90 days increases albumin levels and decreases plasma levels of ammonia, bilirubin, aspartate aminotransferase (AST), blood urea nitrogen (BUN), and creatinine, but does not improve fatigue or quality of life, when compared with placebo (102122). A more recent clinical trial shows that taking L-carnitine 2 grams daily for 24 weeks modestly improves bilirubin levels and some measures of cognitive and liver health, but not quality of life, when compared with taking placebo (111876). Two of the clinical trials included in this analysis also show that taking L-carnitine 2 grams daily for 60-90 days significantly improves cognitive function when compared with placebo in adults with hepatic encephalopathy (58174,58204). Another small clinical trial in patients with advanced liver cirrhosis shows that L-carnitine improves psychometric response to the ammonia tolerance test, suggesting that L-carnitine might be useful in the prevention of hepatic encephalopathy (58872). L-carnitine has also been evaluated in combination with rifaximin. A small clinical study in patients with overt hepatic encephalopathy shows that taking oral L-carnitine 1500 mg in combination with rifaximin 1200 mg three times daily for 12 weeks has no effect on the modified portal systemic encephalopathy index when compared with rifaximin alone. L-carnitine improved blood ammonia levels at 4 weeks, but not at 8 or 12 weeks (107410).
• Hepatitis-related fatigue. It is unclear if oral L-carnitine is beneficial in patients with hepatitis-related fatigue. Details: One small clinical trial in patients with hepatitis C who are receiving interferon-alpha treatment shows that taking L-carnitine 2 grams daily significantly reduces fatigue when compared with interferon-alpha alone. L-carnitine appears to reduce fatigue within the first 3 months of treatment, but not after 6 months (16104).
• Hepatitis B. Oral L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients with hepatitis B shows that taking a specific vitamin complex providing L-carnitine 2472 mg (Godex, Celltrion Pharm) in combination with entecavir 0.5 grams daily for 12 months normalizes alanine transaminase (ALT) levels in 95% and 100% of patients after 3 months and 12 months, respectively, compared to 59% and 86% of patients taking entecavir alone. However, the L-carnitine complex does not appear to improve aspartate transaminase (AST) levels or reduce hepatitis B virus titers (91724). It is unclear if these findings are due to L-carnitine, other ingredients, or the combination.
• Hepatitis C. Small clinical studies suggest that oral L-carnitine may improve response to treatment and markers of liver function in patients with hepatitis C. Details: Two small clinical trials in patients with chronic hepatitis C show that taking L-carnitine 2 grams once or twice daily along with interferon-alpha and ribavirin for 12 months modestly improves response to treatment, increases hemoglobin and red blood cell counts, reduces aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, and reduces steatosis when compared with interferon-alpha and ribavirin treatment alone (58405,59010).
• HIV/AIDS. Although there has been interest in using intravenous L-carnitine to increase CD4 counts in patients with HIV/AIDS, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Hypertension. It is unclear if oral L-carnitine is beneficial for reducing systolic or diastolic blood pressure. Details: A meta-analysis of low-quality clinical studies in adults, both healthy and with underlying health conditions,shows that taking oral L-carnitine 0.5 to 3 grams daily for 4 to 52 weeks does not reduce systolic blood pressure (SBP) or diastolic blood pressure (DBP) when compared with control(115352). The validity of this study is limited by heterogenous methods between clinical trials, including population, dose, and outcome measurements.
• Hyperthyroidism. It is unclear if oral L-carnitine is beneficial in patients with hyperthyroidism. Details: One small clinical trial in females with hyperthyroidism shows that taking L-carnitine 2-4 grams daily for 2-6 months seems to significantly improve symptoms associated with hyperthyroidism, such as palpitations, nervousness, tremors, and asthenia, when compared with placebo (8047).
• Hypertriglyceridemia. It is unclear if oral L-carnitine is beneficial in patients with hypertriglyceridemia. Details: Small clinical studies in patients with hypertriglyceridemia show that taking L-carnitine 1 gram daily for 12 weeks does not reduce triglyceride levels when compared with placebo (59028,59244).
• Hypothyroidism. It is unclear if oral L-carnitine is beneficial for improving fatigue in patients with hypothyroidism. Details: One small clinical trial in patients with secondary hypothyroidism shows that taking L-carnitine (Ildong Pharmaceutical Co.) 990 mg twice daily for 12 weeks in addition to adequate doses of levothyroxine does not reduce overall fatigue severity when compared with placebo. However, taking L-carnitine might improve physical and mental fatigue in patients with secondary hypothyroidism that are less than 50 years of age. L-carnitine might also improve mental fatigue in patients that underwent thyroidectomy for thyroid cancer (95069).
• Infertility. It is unclear if oral L-carnitine is beneficial for female infertility. Details: One uncontrolled clinical trial in females who had failed to conceive in previous in vitro fertilization (IVF) cycles shows that taking L-carnitine (L-CAR Basic Premium; AA Project Co. ltd.) 1000 mg daily for an average of 82 days does not improve the number of retrieved oocytes or fertilization rates when compared with previous IVF cycles. However, embryo quality at days 3 and 5 of insemination was improved, resulting in an increase in the rate of transferable embryos from 60% in previous cycles to 67%, morphologically good-quality embryos from around 46% to 54%, and blastocysts from around 11% to 21%. The most evidence of benefit was seen in those taking L-carnitine for the shortest time length of 7-44 days (96933).
• Intermittent claudication. Although there has been interest in using oral L-carnitine for intermittent claudication, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Liver disease. Small clinical studies suggest that oral L-carnitine may modestly improve some, but not all, lipid parameters in adults with liver disease. Details: A meta-analysis of six small, low-quality clinical trials in patients with hepatitis C, nonalcoholic steatohepatitis (NASH), and nonalcoholic fatty liver disease (NAFLD) shows that taking L-carnitine moderately reduces total cholesterol and slightly reduces triglyceride levels, but does not improve low-density lipoprotein (LDL) cholesterol or high-density lipoprotein (HDL) cholesterol levels, when compared with control. Studies evaluating L-carnitine doses of 2 grams daily or less and study durations of 24 months or longer showed the largest effect on lipid levels (104178). Another meta-analysis of preliminary clinical research in patients with hepatitis B or C, hepatic encephalopathy, NASH, or NAFLD shows that taking L-carnitine modestly reduces levels if aspartate aminotransferase (AST) and alanine aminotransferase (AST) when compared with taking placebo or no L-carnitine. Some of the studies included in this analysis used acetyl-L-carnitine. However, a meta-analysis of two studies investigating the effect of carnitine orotate shows that taking this compound increases the proportion of patients with normal ALT levels by 4.6 fold (111871).
• Liver transplant. It is unclear if oral L-carnitine is beneficial in patients awaiting a liver transplant. Details: One small clinical trial shows that taking L-carnitine 500 mg three times daily while awaiting a liver transplant does not reduce the incidence of primary graft dysfunction (PGD) or non-function (PNF) when compared with placebo. However, survival one month after surgery was 97% in those taking L-carnitine, compared with 74% in those taking placebo (101562). This study may have been inadequately powered to detect a difference in the incidences of PGD and PNF between groups.
• Low birth weight. It is unclear if oral or intravenous L-carnitine is effective for increasing body weight in preterm infants. Several small clinical studies show conflicting results. Details: Several very small clinical trials in preterm infants receiving total parenteral nutrition show that administering L-carnitine orally at a dose of 13-60 mcmol/kg or intravenously at a dose of 10 mg/kg or 50-100 mcmol/kg daily can improve fat utilization and weight gain when compared with control (3633,3634,3635,3636,3637,58902,59097). However, other small clinical studies show that supplementation with L-carnitine does not significantly increase body weight in preterm infants (58190,58800,59161). The reasons for the discrepant findings are unclear, but due to small study size, some of the studies may have been underpowered to detect significant differences between groups.
• Lyme disease. Although there has been interest in using oral L-carnitine for Lyme disease, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Malnutrition. It is unclear if oral L-carnitine is beneficial in children with severe malnutrition. Details: A moderate-sized clinical study conducted in Bangladesh in children aged 9 to 24 months hospitalized with severe acute malnutrition shows that administering oral L-carnitine syrup 100 mg/kg daily for 15 days in addition to standard care does not improve rates of weight gain or reduce durations of hospital stays when compared with placebo (115351).
• Metabolic syndrome. It is unclear if oral or intravenous L-carnitine is beneficial in patients with metabolic syndrome. Details: One very small clinical trial in patients with metabolic syndrome undergoing 2 days of moderate calorie restriction followed by a 5-day modified fasting period shows that intravenous L-carnitine 2 grams twice daily for 7 days increases weight loss by 1.4 kg and decreases waist circumference by 3.3 cm when compared with intravenous saline. Perceived hunger scores, physical fatigue, and insulin levels were also improved. However, there were no effects on blood pressure (90634). Other clinical research in patients with metabolic syndrome and a total carotid plaque volume of at least 50 mm³ shows that taking L-carnitine 2 grams daily for 6 months does not affect the progression of carotid plaque volume when compared with taking placebo. Also, taking L-carnitine increased the progression of carotid plaque stenosis by 9.3%, as well as levels of low-density lipoprotein (LDL) cholesterol, in this population (111879).
• Migraine headache. It is unclear if oral L-carnitine is beneficial in patients with migraine headaches. Details: One small clinical trial in patients with migraines shows that taking L-carnitine 500 mg daily, with or without magnesium oxide, for 12 weeks does not significantly reduce migraine frequency or severity when compared with a control (59030). However, another small preliminary clinical trial in children with episodic migraines shows that taking L-carnitine 25 mg per kg twice daily for 12 weeks prophylactically is as effective as taking propranolol 1 mg/kg once daily for reducing the frequency, severity, and duration of migraine headaches (111870). These studies were small and may have been underpowered to detect differences between groups.
• Muscle cramps. It is unclear if oral L-carnitine is beneficial in patients with muscle cramps. Details: One small, uncontrolled clinical trial in adults with type 2 diabetes shows that taking L-carnitine 300 mg twice daily for 4 months decreases the monthly frequency of muscle cramps from around 4 cramps per month at baseline to around 1 cramp per month after treatment. When compared with baseline, pain was also reduced by about 1 point on a 5-point scale (96922). However, the lack of a placebo control group limits the validity of these findings.
• Multiple sclerosis-related fatigue. It is unclear if oral L-carnitine is beneficial in patients with multiple sclerosis-related fatigue. Details: Some patients with multiple sclerosis have low blood levels of L-carnitine. Additionally, immunosuppressive therapy for multiple sclerosis can cause fatigue. One small, open-label clinical trial in patients with multiple sclerosis receiving immunosuppressive therapy and with low L-carnitine levels shows that taking L-carnitine 3-6 grams daily decreases some measures of fatigue when compared with no treatment (16107).
• Myocardial infarction (MI). It is unclear if oral or intravenous L-carnitine is beneficial in patients who have experienced an MI. Details: Some clinical research shows that taking L-carnitine orally or intravenously after MI reduces premature ventricular beats (58172,59044), improves myocardial viability (59248) and left ventricular function (3628), and reduces mortality (3627,3629,59037). However, other studies show no change in left ventricular functioning (58148) or mortality after taking L-carnitine (3628,58225,90630). The reasons for these discrepant findings are unclear, but may be due to differences in the dosing regimens and length of follow-up. Oral L-carnitine doses have ranged from 2-4 grams daily for up to 12 months (3627,3629,59248). Intravenous L-carnitine has been dosed at 5 grams within the first 36 hours after an MI followed by 3 grams twice daily on days 3-7 (58172), 100 mg/kg every 12 hours for 36 hours (59044), or 9 grams daily for 5 days followed by oral L-carnitine 6 grams daily for 12 months (3628).
• Narcolepsy. It is unclear if oral L-carnitine is beneficial in patients with narcolepsy. Details: One small clinical trial in patients with narcolepsy shows that taking L-carnitine 340 mg in the morning and 170 mg in the evening for 8 weeks reduces dozing off time during the day by about 9 minutes when compared with placebo. However, the number of naps needed, quality of life, and sleepiness are not affected (90624).
• Neonatal apnea. It is unclear if intravenous L-carnitine is beneficial for preventing neonatal apnea in premature infants. Details: One small clinical trial in premature infants shows that adding L-carnitine 30 mg/kg daily to total parenteral nutrition or oral feeds does not affect ventilator requirements or reduce the incidence of apnea when compared with placebo (58163).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral L-carnitine is beneficial in children and adults with NAFLD. Details: One small clinical study in adults with NAFLD shows that taking L-carnitine 600 mg daily for 3 months improves markers of liver function when compared with baseline. No improvements in liver function markers were reported in patients in the control group; however, no statistical comparisons were conducted between groups (58808). A small clinical study in children aged 5-15 years with NAFLD receiving vitamin E shows that taking L-carnitine 25 mg/kg twice daily (maximum of 500 mg twice daily) for 3 months has no effect on aminotransferase concentrations or sonographic grades of fatty liver when compared with placebo (107401).
• Nonalcoholic steatohepatitis (NASH). It is unclear if oral L-carnitine is beneficial in patients with NASH. Details: One small clinical trial in patients with NASH shows that taking L-carnitine 1 gram after breakfast and 1 gram after dinner daily along with following a specific diet improves markers of liver function when compared with diet alone (58715). Another small clinical trial in patients with obesity and nonalcoholic steatohepatitis taking simvastatin 20 mg daily and following a hypocaloric diet shows that taking L-carnitine 10 mL twice daily for 90 days modestly reduces BMI, and improves liver health, lipid, and glycemic indices, when compared with taking a product described as essential phospholipids (111893).
• Obesity. Oral L-carnitine seems to have a small effect on weight loss in overweight or obese individuals when taken for up to 6 months, but some conflicting results exist. Doses of 2 grams daily seem to offer the most benefit. Details: Meta-analyses of clinical trials show that taking L-carnitine 250 mg to 4 grams daily reduces weight and body mass index (BMI) by a small amount when compared with a control group not taking L-carnitine (95074,101563,101564). Subgroup analyses show that L-carnitine only reduces BMI and weight in overweight or obese patients. Taking L-carnitine did not affect weight or BMI in patients with a BMI of up to 25 kg/m2 or in patients undergoing hemodialysis (101563,101564). Another subgroup analysis shows that the largest benefit occurs at a dose of 2 grams daily (101564). In patients with obesity and nonalcoholic steatohepatitis taking simvastatin 20 mg daily and following a hypocaloric diet, one clinical trial shows that taking L-carnitine 10 mL twice daily for 90 days modestly reduces BMI, and improves liver health, lipid, and glycemic indices, when compared with taking a product described as essential phospholipids (111893). However, conflicting results exist. One subgroup analysis in overweight or obese individuals shows that there is no effect on BMI when L-carnitine is taken for 24 weeks or more (101563). One meta-analysis of two small clinical trials in patients with overweight or obesity shows that taking L-carnitine is no more effective than lifestyle modification for reducing body weight (111866). Also, some clinical research shows that taking L-carnitine does not reduce body weight in obese females. Doses used in these studies include L-carnitine 1 gram daily for 12 weeks or 2 grams twice daily for 8 weeks along with exercise (58151,111872). The effect of L-carnitine on cardiovascular risk has also been examined in patients with obesity. One small clinical trial shows that taking L-carnitine 1 gram daily for 12 weeks modestly reduces the lipid accumulation index, based on waist circumference and blood triglyceride levels, when compared with taking placebo. However, there was no effect on other cardiovascular risk indices based on ratios of triglycerides, high-density lipoprotein (HDL) cholesterol, and/or low-density lipoprotein (LDL) cholesterol levels (111872). L-carnitine has also been evaluated in combination with weight loss medications. Clinical research shows that taking L-carnitine 2 grams daily along with orlistat 360 mg daily or sibutramine 10 mg daily for 1 year decreases body weight and BMI when compared with orlistat or sibutramine alone in obese adults with type 2 diabetes (58778,58830,58882).
• Osteoarthritis. It is unclear if oral L-carnitine is beneficial in patients with knee osteoarthritis. Details: A small clinical study in females with knee osteoarthritis and overweight or obesity who are on a low-calorie diet shows that taking L-carnitine 1 gram daily for 12 weeks does not improve pain, stiffness, or physical function when compared with placebo (107403).
• Pemphigus. Although there has been interest in using oral L-carnitine for glucocorticoid-induced muscle wasting in patients with pemphigus, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Peripheral arterial disease (PAD). It is unclear if oral L-carnitine is beneficial in patients with PAD. Details: One small clinical trial in patients with PAD shows that taking L-carnitine 2 grams twice daily for 3 weeks may improve walking distances in people with PAD (3631). However, another small clinical trial in patients with PAD or coronary heart disease shows that taking L-carnitine 2 grams two hours before exercise does not improve endurance (58196). Also, adding L-carnitine 1 gram twice daily to cilostazol therapy for 180 days does not appear to confer additional benefit in this patient population (59023).
• Polycystic ovary syndrome (PCOS). It is unclear if oral L-carnitine is beneficial for improving pregnancy rates or cardiovascular risk in people with PCOS. The effect of L-carnitine on body composition has promising results. Details: Clinical research shows that adding L-carnitine 3 grams daily for 3 months to standard clomiphene plus metformin therapy improves menstrual regularity by 20%, ovulation rate by 24%, and pregnancy rate by 21% when compared with placebo (102123). Preliminary clinical research in patients with PCOS who are resistant to both clomiphene and human chorionic gonadotropin (HCG) shows that taking L-carnitine 2 grams twice daily from day 3 of clomiphene treatment until HCG injection results in the presence of a dominant follicle in 64% of cycles and pregnancy in 20% of cycles (96936). However, L-carnitine may not be beneficial in combination with assisted reproductive technology (ART), including in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). Two small clinical studies in patients with PCOS receiving ART in combination with a gonadotropin-releasing hormone antagonist protocol shows that adding L-carnitine 3000 mg daily starting on the second day of menstruation and continuing until the day of oocyte triggering or embryo transfer does not improve rates of oocyte maturity or retrieval, implantation, or pregnancy when compared with control (107409,115353). The effect of L-carnitine has also been examined on anthropometric and cardiovascular risk indices in patients with PCOS. One small clinical study shows that taking L-carnitine 250 mg daily for 12 weeks reduces body weight by 2.8 kg, body mass index (BMI) by 1.2 kg/m2, waist circumference by 1.7 cm, and hip circumference by 2.2 cm when compared with placebo (96935). A meta-analysis of this and other small studies also shows that L-carnitine modestly reduces BMI when compared with placebo in patients with PCOS (111873). Although several studies also show improvements in markers of glycemic control and insulin sensitivity, most research does not support beneficial effects on lipid levels, cardiovascular risk, or liver fat content (96935,107402,107404,115353).
• Rett syndrome. It is unclear if oral L-carnitine is beneficial in patients with Rett syndrome. Details: Two small clinical studies in children with Rett syndrome show that taking L-carnitine 100 mg/kg daily in two or three divided doses for up to 6 months modestly improves well-being, motor skills, sleep efficiency, and communication skills when compared with control or placebo (1433,58161).
• Sarcopenia. Oral L-carnitine may be beneficial for preventing sarcopenia in adults over 75 years of age, but not in healthy older females. Details: One small clinical trial in healthy, active, older females aged 65-70 years shows that taking L-carnitine, as L-carnitine-l-tartrate 1500 mg, daily for 24 weeks does not improve muscle strength or muscle mass when compared with placebo (96930). An additional preliminary clinical trial in females aged 60-75 years taking part in a twice weekly resistance exercise program shows that taking L-carnitine tartrate 1 gram daily with L-leucine 3 grams daily for 24 weeks does not improve muscle strength or volume when compared with taking L-leucine 4 grams daily or no supplementation (111880). These studies were small and may have been underpowered to detect differences. In contrast, in weaker adults 75 years of age and older, taking L-carnitine 2-4 grams daily for 1-6 months increases muscle mass by approximately 2-4 kg when compared with placebo (16109,16111).
• Sepsis. Small clinical studies suggest that intravenous L-carnitine may not reduce mortality in patients with sepsis, although patients with more severe sepsis may see some benefit. Details: Meta-analyses of generally low-quality small clinical trials in patients with sepsis shows that intravenous administration of L-carnitine, 2-6 grams as a bolus followed by a 4-12 gram infusion, does not reduce the risk of 28-day or 1-year mortality when compared with placebo (104180,111868). However, in a subgroup analysis of patients with more severe sepsis, classified as those with a sequential organ failure assessment score (SOFA) of greater than 12, the risk of 1-year mortality was reduced by 32% when compared with placebo (104180).
• Spinal muscular atrophy. Although there has been interest in using oral L-carnitine for spinal muscular atrophy, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Theophylline-induced cardiac toxicity. It is unclear if intravenous L-carnitine is beneficial in patients with theophylline-induced cardiac toxicity. Details: One small clinical trial shows that intravenous administration of L-carnitine 100 mg/kg over 30-60 minutes followed by 50 mg/kg every 8 hours along with intravenous propranolol within 24 hours of theophylline intoxication improves symptoms associated with theophylline-induced cardiac toxicity when given along with standard treatment. This combination led to greater improvements than either agent used alone. These included improvements in serum theophylline levels, heart rate, arrhythmia, mean arterial pressure, and duration of hospital stay. When L-carnitine was used without propranolol, only respiratory rate and theophylline levels over 24 hours were improved to a greater extent than with standard treatment alone (101566).
• Toxin-induced liver damage. Small clinical studies have evaluated oral and intravenous L-carnitine for the management of liver damage caused by different classes of drugs, including antimycobacterial antibiotics and asparaginase-based agents, with promising results. Details: The antimycobacterial antibiotics used to treat tuberculosis, including isoniazid, rifampicin, and pyrazinamide, have been associated with hepatotoxicity (90922). Clinical research shows that taking L-carnitine 2 grams in two divided doses daily for 4 weeks along with a standard treatment regimen for tuberculosis reduces the percentage of treatment-naïve patients with drug-induced hepatotoxicity by almost half when compared with placebo (26499). The asparaginase-based medications have also been associated with hepatotoxicity. Two case series of children with hyperbilirubinemia caused by treatment with L-asparaginase or pegaspargase show that administering intravenous L-carnitine 50-100 mg/kg daily improves bilirubin levels (100353,100354). One case series also suggests that taking oral L-carnitine 50-100 mg/kg daily can help to prevent hyperbilirubinemia in patients with a history of asparaginase-induced hepatotoxicity (100353).
• Traumatic brain injury (TBI). Although there has been interest in using oral L-carnitine for TBI, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose.
• Urinary tract infections (UTIs). It is unclear if oral L-carnitine is beneficial in children with UTIs. Details: One small clinical trial in children 6 months to 10 years of age shows that taking L-carnitine 50 mg/kg daily as a syrup along with antibiotics for 7 days prevents renal scarring associated with acute pyelonephritis. Kidney damage was resolved in 50% of children taking L-carnitine, compared with 13% of children taking placebo. There were no differences in urine cultures between groups (101568).
• Venous leg ulcers. Although there has been interest in using oral L-carnitine for venous leg ulcers, there is insufficient reliable information about the clinical effects of L-carnitine for this purpose. More evidence is needed to rate L-carnitine for these uses.

(Read more about L-CARNITINE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alopecia areata. It is unclear if raspberry ketone is beneficial for alopecia areata. Details: Preliminary clinical research shows that applying a raspberry ketone 0.01% solution to the scalp once daily for 5 months increases hair growth in 50% of patients with androgenic alopecia or alopecia areata when compared with baseline (17955). The validity of this finding is limited by the lack of a comparator group.
• Androgenic alopecia. It is unclear if raspberry ketone is beneficial for androgenic alopecia. Details: Preliminary clinical research shows that applying a raspberry ketone 0.01% solution to the scalp once daily for 5 months increases hair growth in 50% of patients with androgenic alopecia or alopecia areata when compared with baseline (17955). The validity of this finding is limited by the lack of a comparator group.
• Obesity. Raspberry ketone has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small, uncontrolled clinical trial in healthy adults suggests that taking raspberry ketone 200 mg with vitamin C 1200 mg daily for four weeks reduces body weight and body fat mass (19065). Another clinical study in overweight adults shows that taking a specific product (Prograde Metabolism, Ultimate Wellness Systems) containing 1000 mg of a proprietary blend of raspberry ketone, capsicum extract, caffeine, garlic root, ginger root, bitter orange, L-theanine, and black pepper twice daily for 8 weeks, in conjunction with dieting, reduces body weight, fat mass, and waist and hip circumference when compared with dieting alone (40802). More evidence is needed to rate raspberry ketone for these uses.

(Read more about RASPBERRY KETONE)

POSSIBLY SAFE ...when used orally in amounts commonly found in foods. Arnica has Generally Recognized As Safe (GRAS) status for use as a food flavoring in the US (4912). However, Canadian regulations do not allow its use as a food ingredient (12). ...when used orally in homeopathic dilutions of 30C and up to 5C (19110,19111,19117,19124,19126,96769). ...when used topically on unbroken skin, short-term (12).

LIKELY UNSAFE ...when used orally or when applied topically to broken skin. Arnica is considered poisonous and has caused severe or fatal poisonings (5). Arnica can cause gastroenteritis, muscle paralysis, bleeding, arrhythmia, hypertension, shortness of breath, nausea and vomiting, multi-organ failure, and death (4,5,17,104,19101,19102,19103,19104,19105,19106,19107,19108).

PREGNANCY AND LACTATION: LIKELY UNSAFE
when used orally or topically; avoid using (12).

(Read more about ARNICA)

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

POSSIBLY UNSAFE ...when used orally in medicinal amounts. The volatile oil (2.5% in the leaf) contains the liver toxin ascaridole (4). Boldo has also been linked to a documented case of liver damage (13178). If boldo preparations are taken for medicinal purposes, only ascaridole-free preparations should be used. There is insufficient reliable information available about the safety of boldo when used topically.

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in medicinal amounts. In animals, boldo and the constituent boldine have abortive and teratogenic effects (100302). Also, the ascaridole constituent of boldo is a liver toxin (4).

(Read more about BOLDO)

There is insufficient reliable information available about the safety of garcinia extract when used orally. However, there is some concern about liver toxicity. There are numerous case reports of elevated liver enzymes and symptoms of liver toxicity in patients who have taken garcinia alone or in combination with other ingredients for as little as one week. In at least two reports, hepatotoxicity occurred in patients who were taking garcinia alone. Most other reports occurred in patients taking multi-ingredient products (13037,53511,93380,93381,93384,93385,93392,93393,93394,96535)(102544,102545,111241).

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

(Read more about GARCINIA)

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

POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts. Hibiscus sabdariffa tea has been safely consumed in amounts of up to 720 mL daily for up to 6 weeks (16894,93805,93814). Hibiscus sabdariffa extracts, including a specific Hibiscus sabdariffa leaf extract (Green Chem), have also been safely used in doses of up to 1000 mg daily for up to 90 days (17415,54989,93805,93809,105307).

CHILDREN: POSSIBLY SAFE
when used orally and appropriately. Hibiscus sabdariffa calyx powder has been used with apparent safety at a dose of 2 grams three times daily for 4 weeks by adolescents aged 12-18 years (93816).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Hibiscus sabdariffa is thought to be a menstrual stimulant, and might have abortifacient effects (19).

LACTATION: POSSIBLY UNSAFE
when used orally in large amounts. Animal research found that administering large doses of Hibiscus sabdariffa during lactation decreases food and water intake during pregnancy and delays puberty in offspring (93810); however, this has not been assessed in humans.

(Read more about HIBISCUS SABDARIFFA)

There is insufficient reliable information available about the safety of hoodia.

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

(Read more about HOODIA)

POSSIBLY UNSAFE ...when horsetail products containing thiaminase are used orally, long-term. Thiaminase is an enzyme that destroys thiamine, which could theoretically lead to thiamine deficiency. In Canada, horsetail products are required to be thiaminase-free (105301).

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

(Read more about HORSETAIL)

LIKELY SAFE ...when used orally and appropriately. L-carnitine has been safely used in clinical trials lasting up to 12 months (1947,3620,3621,3623,3624,3625,3626,3627,3628,3629) (3630,3639,4949,8047,9790,12352,16104,16105,16106,16107) (16109,16110,23437,26496,26499,58150,58156,58161,58169,58182) (58189,58204,58207,58209,58213,58294,58523,58554,58556,58647) (58679,58715,58778,58793,58830,58831,58882,59023,59029,59043) (90624,90633,104177,111872,111876,111883,111884,111891,111898). ...when used parenterally as an FDA-approved prescription medicine. Avoid using D-carnitine and DL-carnitine. These forms of carnitine can act as competitive inhibitors of L-carnitine and may cause symptoms of L-carnitine deficiency (1946).

CHILDREN: POSSIBLY SAFE
when used orally or intravenously and appropriately. L-carnitine has been safely used orally in children for up to 6 months (1433,3622,58166,58502,58981,59188,111887,111900,115351). It has also been safely used orally and intravenously in preterm infants (3633,3634,3635,3636,3637,58163,58190,58800,58902,59097)(59161).

PREGNANCY:
Insufficient reliable information available; avoid using.

LACTATION: POSSIBLY SAFE
when used orally. Supplemental doses of L-carnitine have been given to infants in breast milk and formula with no reported adverse effects. The effects of large doses used while nursing are unknown, but L-carnitine is secreted in the breast milk (3616).

(Read more about L-CARNITINE)

LIKELY SAFE ...when used orally in food amounts. Raspberry ketone has Generally Recognized as Safe (GRAS) status for use as a food additive (102356,102358). There is insufficient reliable information available about the safety of raspberry ketone when used in medicinal amounts. However, raspberry ketone is structurally similar to synephrine, a known stimulant agent. Orally, cases of heart palpitations, tachycardia, elevated blood pressure, coronary vasospasm, sweating, feelings of shakiness, and diarrhea are reported after taking raspberry ketone (17961,112386,112400). In one case report, pulseless electrical activity arrest followed by resistant polymorphic ventricular tachycardia occurred in a patient taking raspberry ketone (112386).

PREGNANCY AND LACTATION:
There is insufficient reliable information available about the safety of raspberry ketone; avoid using.

(Read more about RASPBERRY KETONE)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, arnica might have additive effects with anticoagulant and antiplatelet drugs. Homeopathic arnica preparations are unlikely to have this interaction.  Details In vitro evidence shows that sesquiterpene lactones in arnica flowers can decrease platelet aggregation (104). However, this effect has not been reported in humans.

(Read more about ARNICA)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking boldo with anticoagulant/antiplatelet drugs might increase the risk of bleeding.  Details Animal and in vitro research shows that boldine, a constituent of boldo, has antiplatelet activity (5191,36789). In one case report, an adult taking a combination of boldo and fenugreek with warfarin experienced an increase in international normalized ratio (INR); however, it is unclear if this effect was due to boldo, fenugreek, the combination, or another factor (5191).

HEPATOTOXIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking boldo with hepatotoxic drugs might increase the risk of hepatic injury and disease.  Details Boldo leaf contains ascaridole, a known liver toxin. Many cases of hepatotoxicity, including elevated liver transaminase levels and jaundice, have been reported in patients taking boldo (13178,100304,106431).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, taking boldo with lithium might increase the levels and clinical effects of lithium.  Details Boldo is believed to have diuretic effects (4). Theoretically, these diuretic effects might reduce the excretion of lithium. The dose of lithium might need to be decreased.

TACROLIMUS (Prograf) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Taking boldo with tacrolimus may decrease the levels and clinical effects of tacrolimus, potentially increasing the risk of transplant rejection.  Details In one case report, a patient with a long-term history of stable tacrolimus levels developed subtherapeutic levels after taking boldo 300 mg twice daily orally for several weeks. Tacrolimus levels returned to normal after discontinuing boldo. However, the mechanism of this interaction is unclear (92601).

(Read more about BOLDO)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, hydroxycitric acid (HCA), the main active ingredient in garcinia, might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.  Details HCA inhibits platelet aggregation in vitro. The inhibitory effect seems to be greater in platelets extracted from diabetic subjects than non-diabetic subjects (26862).

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, hydroxycitric acid (HCA), the main active ingredient in garcinia, might have additive effects with antidiabetes drugs and increase the risk of hypoglycemia.  Details HCA reduces fasting and postprandial blood glucose levels in animal models, theoretically by delaying glucose absorption (26863,26867,26868). This effect has not been reported in humans.

HEPATOTOXIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use with other potentially hepatotoxic drugs might increase the risk of developing liver damage.  Details There have been reports of acute hepatitis with elevated liver enzymes associated with garcinia, when taken alone or in combination with other ingredients (13037,53511,93380,93381,93384,93392,93393,93394,102544,102545). Case reports collected from the Drug Induced Liver Injury Network suggest this risk may be greater in people who carry the HLA B*35:01 allele (108401).

SEROTONERGIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, combining garcinia with other serotonergic drugs might increase the risk of serotonergic side effects, including serotonin syndrome.  Details In one report, a patient experienced serotonin syndrome after taking garcinia extract (60% hydroxycitric acid) 1000 mg daily in combination with escitalopram 20 mg, which had been taken for a year. The patient was switched to sertraline 50 mg daily and again experienced serotonin syndrome (23545).

(Read more about GARCINIA)

ACETAMINOPHEN (Tylenol, others) Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Probable •  Level of Evidence = B Theoretically, taking Hibiscus sabdariffa with acetaminophen might decrease the clinical effects of acetaminophen.  Details There is some evidence that consuming a Hibiscus sabdariffa beverage (Zobo drink) before taking acetaminophen can decrease the elimination half-life of acetaminophen. Hibiscus sabdariffa does not seem to decrease maximum concentration or area under the curve of acetaminophen (12184). The clinical significance of this is unknown.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking Hibiscus sabdariffa with antidiabetes drugs might increase the risk of hypoglycemia.  Details Most clinical research shows that Hibiscus sabdariffa can reduce blood glucose levels (54999,105304,105305).

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking Hibiscus sabdariffa with antihypertensive drugs might increase the risk of hypotension.  Details Most clinical evidence suggests that taking Hibiscus sabdariffa reduces systolic and diastolic blood pressure (16894,54985,54995,105304). In animal research, Hibiscus sabdariffa increased the hypotensive effects of single doses of losartan and amlodipine (102459,107901).

CHLOROQUINE (Aralen) Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = B Taking Hibiscus sabdariffa tea along with chloroquine seems to reduce levels of chloroquine.  Details When taken together, Hibiscus sabdariffa tea significantly reduces the bioavailability of chloroquine (55004). This may reduce its clinical effects. People taking chloroquine for the treatment or prevention of malaria should avoid Hibiscus sabdariffa tea.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP1A2 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP1A2 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 2A6 (CYP2A6) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2A6 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2A6 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2B6 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2B6 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2C19 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2C19 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 2C8 (CYP2C8) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa might reduce the metabolism of CYP2C8 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2C8 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2C9 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2C9 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2D6 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2D6 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP2E1 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP2E1 (93811). This interaction has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa extract might reduce the metabolism of CYP3A4 substrates.  Details In vitro research shows that Hibiscus sabdariffa calyx extract inhibits CYP3A4 (93811). This interaction has not been reported in humans.

DICLOFENAC (Voltaren, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Taking Hibiscus sabdariffa with diclofenac may increase the levels and adverse effects of diclofenac.  Details Pharmacokinetic research in humans shows that drinking a beverage made with Hibiscus sabdariffa flowers reduces the excretion of diclofenac by approximately 38% when compared with water. The clinical significance of this is unknown (101726).

LOSARTAN (Cozaar) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Hibiscus sabdariffa might increase the levels and clinical effects of losartan.  Details Animal research in rats with laboratory-induced hypertension shows that providing Hibiscus sabdariffa for 14-17 days prior to a single administration with losartan modestly increases losartan concentrations and increases hypotensive effects when compared with a single administration of losartan alone (102459). It is not clear if Hibiscus sabdariffa alters the concentration or effects of losartan when taken continuously. Additionally, this interaction has not been shown in humans.

SIMVASTATIN (Zocor) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Taking Hibiscus sabdariffa with simvastatin might reduce the levels and clinical effects of simvastatin.  Details A pharmacokinetic study in humans shows that taking a beverage prepared with dried Hibiscus sabdariffa flower 300 grams concurrently with a single dose of simvastatin 40 mg increases the clearance of simvastatin by about 45% and reduces peak levels of simvastatin by 18% (96270).

(Read more about HIBISCUS SABDARIFFA)

(Read more about HOODIA)

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking horsetail with antidiabetes drugs might increase the risk of hypoglycemia.  Details Equisetum myriochaetum has demonstrated hypoglycemic activity in clinical research (13576). In an animal diabetic model, Equisetum giganteum had hypoglycemic effects (105300). It is unclear whether other horsetail species have hypoglycemic effects.

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking horsetail with diuretic drugs might increase potassium loss and the risk of hypokalemia.  Details Laboratory research shows that various species of horsetail have diuretic properties (13574,13575). Due to its diuretic effects, there has been concern that taking horsetail along with potassium-depleting diuretics might increase the risk for hypokalemia. However, pharmacokinetic research in humans shows that taking horsetail 900 mg daily for 4 days does not affect urinary excretion of electrolytes, including potassium and sodium, despite having a diuretic effect similar to taking hydrochlorothiazide 25 mg daily (92288). It is unclear if taking horsetail for a longer duration would affect electrolyte levels. Until more is known, use with caution.

EFAVIRENZ (SUSTIVA) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, horsetail might decrease the levels and clinical effects of efavirenz.  Details In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral regimen that included efavirenz. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing horsetail, the viral loads became undetectable in both cases. The exact mechanism of this interaction is unknown (97573). It is also unclear if this interaction is specific to efavirenz or if it is related to various components of antiretroviral therapy.

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, horsetail might increase the levels and adverse effects of lithium.  Details Animal research suggests that horsetail has diuretic properties (13574). Theoretically, due to these potential diuretic effects, horsetail might reduce excretion and increase levels of lithium. The dose of lithium might need to be decreased.

NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITORS (NRTIs) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, horsetail might decrease the levels and clinical effects of NRTIs.  Details In two case reports, patients were found to have detectable viral loads when taking horsetail-containing supplements along with an antiretroviral therapy. In one case, the antiretroviral regimen included zidovudine, lamivudine, and efavirenz; in the other case, the regimen consisted of emtricitabine, tenofovir disoproxil fumarate, and efavirenz. One month after discontinuing the supplement, the viral loads became undetectable in both cases. The exact mechanism of these interactions is unknown (97573). It is also unclear if these interactions are specific to NRTIs or if they are related to various components of antiretroviral therapy.

(Read more about HORSETAIL)

ACENOCOUMAROL (Sintrom) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, L-carnitine might increase the anticoagulant effects of acenocoumarol.  Details L-carnitine might enhance the anticoagulant effects of acenocoumarol, an oral anticoagulant similar to warfarin, but shorter-acting (9878,12165). There are at least two case reports of INR elevation with concomitant use. In one case, a 33-year-old male with a previously stable INR had an elevated INR of 4.65 after L-carnitine was started and continued for 10 weeks. INR normalized after discontinuation of the L-carnitine-containing product (12165).

THYROID HORMONE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, L-carnitine might decrease the effectiveness of thyroid hormone replacement.  Details L-carnitine appears to act as a peripheral thyroid hormone antagonist by inhibiting entry of thyroid hormone into the nucleus of cells (12761). Taking L-carnitine also seems to diminish some of the symptoms of hyperthyroidism (8047).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, L-carnitine might increase the anticoagulant effects of warfarin.  Details L-carnitine might increase the anticoagulant effects of acenocoumarol, a shorter-acting oral anticoagulant similar to warfarin (9878,12165). There is not enough information to know whether this interaction occurs with L-carnitine and warfarin.

(Read more about L-CARNITINE)

STIMULANT DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, raspberry ketone might increase the risk of adverse cardiovascular effects with stimulant drugs.  Details Structurally, raspberry ketone resembles synephrine, a known stimulant agent. Heart palpitations, elevated blood pressure, coronary vasospasm, pulseless electrical activity arrest, and resistant polymorphic ventricular tachycardia have been reported in patients taking raspberry ketone (17961,112386,112400).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, raspberry ketone might increase warfarin dose requirements.  Details In one case report, a patient taking warfarin 55 mg per week had a decrease in INR over a period of one month while taking raspberry ketone 250 mg daily. A warfarin dose increase to 70 mg per week was necessary to maintain a therapeutic INR while taking raspberry ketone (17962). The mechanism for this potential interaction is not known.

(Read more about RASPBERRY KETONE)

General ...Orally, arnica is unsafe and can cause toxicity. When used in homeopathic amounts, arnica seem to be generally well tolerated. Topically, arnica also seems to be generally well tolerated.
Most Common Adverse Effects:
Orally: Bleeding, gastroenteritis, hypertension, muscle paralysis, nausea and vomiting, shortness of breath.
Topically: Contact dermatitis and irritation.
Serious Adverse Effects (Rare):
Orally: Arrhythmia, coma, multi-organ failure, and death.

Cardiovascular ...Orally, arnica can cause tachycardia or a faster heart rate (11,17113,19101,19102). A 24-year-old female presented to the emergency department with palpitations and vomiting 24 hours after ingesting a cup of tea that reportedly contained arnica flowers picked from her local area of mountainous Southern California. The species was not specified in the article and there was no indication by the authors that any testing had been done to confirm the identity of the plant (90610).

Dermatologic ...Orally, arnica can cause irritation of mucous membranes (11,17113). Topically, arnica can cause contact itchiness, dry skin, and rash (17113). Oral lesions resulted in a woman who used a mouthwash incorrectly by not following dilution instructions. The mouthwash was 70% alcohol and contained arnica and oil of peppermint (19106).

Gastrointestinal ...Orally, arnica can cause stomach pain, nausea, vomiting, and diarrhea (11,17113,19101,19102). Homeopathic arnica has been reported to cause dry mouth (30C) and sore tongue (6C) (19107). A 24-year-old female presented to the emergency department with palpitations and vomiting 24 hours after ingesting a cup of tea that reportedly contained arnica flowers picked from her local area of mountainous Southern California. The species was not specified in the article and there was no indication by the authors that any testing had been done to confirm the identity of the plant (90610).

Musculoskeletal ...Adverse effects after ingesting arnica include muscle weakness (19101). Homeopathic arnica has been reported to result in the feeling of a "throbby" head or neck (19107).

Neurologic/CNS ...Orally, arnica may cause drowsiness, nervousness, and headache (11,17113,19101,19107).

Ocular/Otic ...In a case report, accidental intake of a large amount of a homeopathic Arnica-30 resulted in acute vision loss due to bilateral toxic optic neuropathy (19105).

Psychiatric ...Oral homeopathic arnica (6C) may cause depressed feelings, specifically a feeling of unhappiness (19107).

Pulmonary/Respiratory ...Orally, arnica can cause shortness of breath (11,17113).

(Read more about ARNICA)

General ...Orally, boldo is generally well tolerated when used in amounts commonly found in foods. However, when used in medicinal amounts, boldo can cause significant adverse effects such as hepatotoxicity. There is currently a limited amount of information on the adverse effects of topical boldo; however, a thorough evaluation of safety outcomes has not been conducted.
Most Common Adverse Effects:
Orally: Abdominal pain, nausea, vomiting.
Topically: Dermatitis.
Severe Adverse Effects (Rare):
Orally: Hepatotoxicity, jaundice.

Cardiovascular ...In one report, a 39-year-old obese female developed palpitations and syncope after taking a weight loss supplement containing a combination of boldo, dandelion, and bladderwrack for 3 weeks. The patient was found to have prolonged QT-interval on ECG and frequent episodes of sustained polymorphic ventricular tachycardia (14321). It is not clear whether boldo, another ingredient, or the combination of ingredients is responsible for this adverse effect. The product was not analyzed to determine the presence of any potential toxic contaminants.

Dermatologic ...Topically, boldo can be irritating when applied to the skin (4). In one case report, a healthy 64-year-old patient experienced allergic contact dermatitis in an airborne pattern on the face, arms, and dorsum of both hands following airborne exposure to boldo. After exposure to boldo was avoided, the dermatitis resolved (106433).

Gastrointestinal ...In one case report, a manufacturer of an herbal laxative reformulated their product to contain boldo. Within 5 months of switching to this reformulated product, an 82-year-old male developed abdominal discomfort with gastrointestinal upset including heartburn (13178). In another case, a 72-year-old female reported nausea, vomiting, and anorexia, which were thought to be associated with hepatotoxic effects of a boldo infusion (100304).

Hepatic ...Orally, boldo is thought to potentially cause hepatotoxicity. The volatile oil from the boldo leaf contains the liver toxin, ascaridole. In one case report, a manufacturer of an herbal laxative reformulated their product to contain boldo. Within 5 months of switching to this reformulated product, an 82-year-old male with mild hepatic steatosis and very small gallbladder stones developed elevated liver transaminase levels. Levels normalized following discontinuation of the herbal product (13178). Several other cases of hepatotoxicity have been reported in elderly patients who received infusions of boldo leaves. These patients presented with elevated liver transaminase and bilirubin levels, sometimes up to 200 times the upper limit of normal, as well as nausea, vomiting, anorexia, asthenia, and jaundice. Lab tests and symptoms normalized a few days after stopping boldo (100304,106431).

Immunologic ...Boldo intake has been linked to one case of IgE-mediated anaphylactic allergic reaction (13185).

(Read more about BOLDO)

General ...Orally, garcinia and its constituent, hydroxycitric acid (HCA), seem to be generally well tolerated in clinical research.
Most Common Adverse Effects:
Orally: Diarrhea, gastrointestinal discomfort, headache, and nausea.
Serious Adverse Effects (Rare):
Orally: Garcinia has been linked with cases of hepatotoxicity and liver failure. There have also been rare cases of mania and pancreatitis.

Cardiovascular ...There is a case report of a 48-year-old female who developed acute necrotizing eosinophilic myocarditis (ANEM) after using a garcinia supplement orally for 2. 5 weeks. On admission to hospital, she was hypotensive and had an elevated serum troponin level, progressing to fulminant heart failure, acute kidney failure, and sustained ventricular arrhythmias. She recovered after treatment with extra-corporeal membrane oxygenation (ECMO) and high-dose corticosteroids (88160). Although the patient had no prior medical history and was not taking any medications, this cannot conclusively be attributed to garcinia.
When taken orally, a specific formulation of the multi-ingredient product Hydroxycut (Iovate Health Sciences Inc.), which was available until 2009, has been associated with malignant hypertension and hypertensive retinopathy. Hydroxycut contains caffeine, garcinia, gymnema, green tea, glucomannan, guarana extract, and willow bark. The suspected causal agent is caffeine, which is dosed at 600 mg daily if Hydroxycut is taken as recommended; however, the responsibility of the other ingredients cannot be ruled out (16527).

Endocrine ...In one case report, a 56-year-old female with pre-existing diabetes, hepatitis C, and hypertension developed diabetic ketoacidosis (DKA) and pancreatitis after taking an unknown amount of garcinia and African mango for one month. Upon admission, she presented with altered mental status, elevated serum glucose and lipase, and high anion gap metabolic acidosis. After 3 days of intensive supportive care, the DKA and pancreatitis resolved. The suspected probable causal agent was garcinia; however, African mango cannot be ruled out (97341). There have been at least 3 other cases of acute pancreatitis associated with use of garcinia (unknown dose) for 2 weeks and up to 7 months in adults ages 36-82 years (105056,105058,105071).

Gastrointestinal ...Orally, garcinia and its active constituent hydroxycitric acid (HCA) have caused mild and infrequent nausea, diarrhea, and other gastrointestinal symptoms (728,11977,19153,88158,88159).

Hepatic ...Orally, garcinia and its constituent hydroxycitric acid (HCA) might cause liver toxicity. Several cases of acute liver toxicity have been reported in patients taking garcinia supplements (93392,93393,93394,95573,102544,102545,104431,111241). Reported doses of garcinia extract range from 480-1800 mg daily, providing up to 900 mg HCA daily (93392,93394,95573,102544,104431). However, not all experts agree that HCA plays a causal role in the hepatotoxicity associated with garcinia supplements; some suggest other mechanisms may be in play, such as immune-mediated processes (95576,108401). In most cases, patients presented with a hepatocellular pattern of toxicity and symptoms of abdominal pain, coagulopathy, jaundice, and elevated transaminases after taking garcinia for several weeks to several months (93393,93394,95573,102544,102545,104431,108401,111241). In most of these cases, there was no evidence of other natural causes of liver disease, such as viral hepatitis. Some of these patients used acetaminophen at recommended doses for limited durations, suggesting that a potential synergistic effect may occur when multiple hepatotoxic agents are used concomitantly.
The Drug-Induced Liver Injury Network has identified 22 cases (11 moderate; 7 severe) of liver injury from garcinia, with 5 cases occurring with garcinia alone, 16 cases occurring in combination with green tea, and 1 case occurring in combination with ashwagandha. Clinical presentations of liver injury related to garcinia closely resemble green tea-related liver injury. Most patients (82%) presented with a hepatocellular pattern of enzyme elevations. The median age of these case reports was 35 years, 41% identified as Hispanic, and most patients were overweight but not obese. In case reports involving garcinia alone, the carrier frequency on HLAB*35:01 was 60%, which is higher than the carrier frequency found in reports of liver injury due to other supplements (19%) and in population controls (11%). Within 3 months of injury onset, 1 patient required liver transplantation and 1 patient died from liver injury (108401).
There have been at least four cases of liver failure requiring transplantation associated with garcinia supplements (93392,95573,98425,104431). In one case related specifically to garcinia, a 52-year-old female had been taking a combination product (USA Nutra Labs) providing garcinia 1000 mg daily, standardized to 60% HCA. The supplement also provided calcium 50 mg, chromium 200 mcg, and potassium 50 mg. Symptoms started within a few weeks of initiation of the product (93392). In another case, a 34-year-old Hispanic male experienced acute liver failure requiring transplant after taking a specific garcinia product (Garcinia Cambogia 5:1 Extract, Swanson Vitamins) 160 mg three times daily before meals for 5 months (95573). In other reports, one 26-year-old male and one female presented to the emergency room with liver failure after 2-7 months of taking a supplement containing garcinia and green tea, with or without whey protein, Veldt raisin, and coffea arabica (98425,104431).
There have also been numerous cases of acute liver toxicity associated with combination products containing garcinia, such as Hydroxycut (Iovate Health Sciences Inc) (13037,53511,93380,93381,93384,93385,96535,98425,104431). Available until 2009, Hydroxycut contained garcinia, green tea, chromium, caffeine, calcium, potassium, and gymnema. A currently available garcinia-containing combination product called Seryburn Day Triple has also been associated with supplement-induced liver injury. (13037,93380,93381,95570,95572,95575,111241). In most of these cases, patients had elevated levels of liver enzymes without evidence of chronic liver disease. Patients usually developed symptoms within 1-12 weeks of taking the product. The clinical pattern of liver damage was often hepatocellular. Most cases reported altered liver enzyme values including ALT, AST, bilirubin, alkaline phosphatase, and international normalized ratio. In most cases, symptoms resolved with near normalization of enzyme levels once the garcinia-containing combination product was discontinued (13037,53511,93380,93381,93384,95567,95572,95575,111241).
However, there is one report of transplant related to Hydroxycut use (93381). As the suspected causal agents, garcinia and green tea were removed from the product during reformulation in 2009 (13037,53511,93380,93381,93384). Hepatotoxicity has been reported in at least one new formulation of Hydroxycut not containing garcinia (93394). Consequently, some experts believe that there is not enough information to attribute hepatotoxicity from this product to garcinia or HCA (95576). Also, in some cases, causality of hepatotoxicity was less clear because patients were taking many other supplements and drugs (95570).There is also a report of fatal liver failure in an obese female taking montelukast while also taking two dietary supplements containing multiple ingredients, including garcinia, gymnema, chromium, bitter orange, and many others. The authors speculated that the combination of montelukast with one or more ingredients in these dietary supplements may have resulted in liver failure (93385).

Musculoskeletal ...Orally, garcinia-containing products have been associated with rhabdomyolysis. There is a case report of a patient who developed rhabdomyolysis 3 hours after ingestion of an herbal product containing ephedra, guarana, chitosan, gymnema, garcinia, and chromium (19154). Since there were multiple ingredients, the effect cannot be conclusively attributed to garcinia. Another case of rhabdomyolysis has been reported for a patient taking an undetermined formulation of Hydroxycut at a dose of 4 caplets daily, naproxen sodium 220 mg as needed for pain, dextroamphetamine daily for 5 days, and hydrocodone-acetaminophen and cyclobenzaprine for pain. Two weeks later, after stopping Hydroxycut and receiving supportive care, the rhabdomyolysis resolved. Hydroxycut was determined to be possibly associated with the rhabdomyolysis (95566). Since Hydroxycut contains multiple ingredients and garcinia content was possible but not confirmed, a causal relationship with garcinia could not be determined.

Neurologic/CNS ...Orally, garcinia and its active constituent hydroxycitric acid (HCA) may cause headache and dizziness (11977). A 35-year-old female reported ocular complications, headache, dizziness, and nausea after taking garcinia extract, providing more than 500 mg of HCA, three times daily for one week. The patient's neurologic symptoms resolved one day after discontinuing the garcinia extract (102546). It is unclear if these neurologic adverse effects were separate from or related to the patient's visual disturbances.

Ocular/Otic ...In one case, a 35-year-old female presented with ocular pain in both eyes, decreased vision in the left eye, headache, dizziness, and nausea after taking garcinia extract orally for one week. Ophthalmologic testing was consistent with adverse ocular effects, showing myopic shift with anterior chamber shallowing and swelling of retinal nerve fiber and macula. The patient reported taking a garcinia product containing hydroxycitric acid 500 mg three times daily, which was more than double the recommended dose per the product label. Symptoms resolved upon discontinuation of the garcinia extract and treatment with oral and topical steroids (102546).

Psychiatric ...Orally, garcinia supplements have been linked to several cases of mania. Typically, symptoms develop 1-8 weeks after starting garcinia. In a report of three patients, symptoms included reduced need for sleep, increased activities and spending, delusions of grandiosity, pressured speech, and agitation. Two of the patients were previously diagnosed with bipolar disorder, and use of garcinia was believed to precipitate episodes during stable phases of the disease. The third patient had no history of bipolar disorder, and use of garcinia was thought to possibly have unmasked previously undiagnosed primary bipolar disorder. In all three cases, recovery included discontinuation of garcinia (95568). In a separate case report, a 23-year-old male taking a specific combination product containing garcinia (Hydroxycut) 1-2 capsules daily for 1 month presented to the emergency room with mania. The patient had no history of bipolar disorder. Although the patient was started on risperidone and clonazepam, symptoms resolved following discontinuation of the supplement. Treatment was discontinued within 4 days of initiation, and the patient remained asymptomatic (95574). A 22-year-old female with no history of bipolar disorder developed mania and psychosis, presenting 10 days after starting Garcinia Cambogia Plus (Apex Vitality Health) 500-1500 mg daily, and Cleanse and Detox (Apex Vitality Health). The latter supplement contains raspberry ketones, licorice root, pumpkin seed, buckthorn root, Cascara sagrada, Irvingia gabonensis, rhubarb, pectin, Lactobacillus acidophilus, and aloe. Symptoms improved upon stopping the supplements and starting lithium and quetiapine (99421).

(Read more about GARCINIA)

General ...Orally, Hibiscus sabdariffa is generally well tolerated.

Gastrointestinal ...Orally, taking a specific Hibiscus sabdariffa leaf extract (Green Chem) 1 gram daily has been associated with reports of transient gastrointestinal symptoms such as abdominal distention, flatulence, and epigastric pain in one clinical trial. However, the overall rate of these adverse effects was similar to placebo (17415). Taking Hibiscus sabdariffa calyx extract 6 grams daily has been associated with single cases of nausea in one clinical trial (55000). Taking Hibiscus sabdariffa calyx powder 6 grams daily has been associated with reports of mild and transient constipation in one clinical trial (93816). Taking 0.5-1 liters of tea daily, made by steeping 10-15 grams of dried Hibiscus sabdariffa calyces, has been associated with one report of stomach pain in one clinical trial (101733).

Genitourinary ...Orally, taking Hibiscus sabdariffa calyx extract 6 grams daily has been associated with one report of dysuria in one clinical trial (55000).

Neurologic/CNS ...Orally, taking Hibiscus sabdariffa calyx extract 3 grams daily has been associated with one report of tremor and headache in one clinical trial (55000).

Ocular/Otic ...Orally, taking Hibiscus sabdariffa calyx extract 3 grams daily has been associated with one report of tinnitus in one clinical trial (55000).

Pulmonary/Respiratory ...Taking 0. 5-1 liters of tea daily, made by steeping 10, 15, or 20 grams of dried Hibiscus sabdariffa calyces, has been associated with two reports of dyspnea in one clinical trial. A clear association with Hibiscus sabdariffa could not be made (101733).

(Read more about HIBISCUS SABDARIFFA)

General ...Orally, hoodia has been reported to cause minor adverse effects including disturbances of skin sensation, headache, dizziness, giddiness, and nausea (18052). There is also concern that hoodia may increase blood pressure and heart rate (18052).

Cardiovascular ...Orally, hoodia might increase blood pressure and heart rate. Clinical research in healthy women shows that intake of purified hoodia extract containing steroid glycosides increases systolic blood pressure by 5.9 to 15.9 mmHg, diastolic blood pressure by 4.6 to 11.5 mmHg, and heart rate by 4.8 to 12.4 beats per minute (18052).

Dermatologic ...Orally, hoodia extract has been reported to cause disturbances of skin sensation (18052).

Gastrointestinal ...Orally, hoodia extract has been reported to cause nausea (18052).

Neurologic/CNS ...Orally, hoodia extract has been reported to cause headache, dizziness, and giddiness (18052).

(Read more about HOODIA)

General ...There is limited clinical research evaluating the safety of horsetail.
Most Common Adverse Effects:
Orally: Abdominal distension, increased bowel movements, and nausea.

Dermatologic ...In one case report, a patient developed seborrheic dermatitis after topical application of horsetail, requiring treatment with local epinephrine and oral antihistamines. The nicotine component of horsetail was determined to be the likely cause of this reaction (13563).

Gastrointestinal ...Orally, horsetail has been associated with mild gastrointestinal side effects including abdominal distension, increased frequency of bowel movements, and nausea (55576). Orally, chronic consumption of horsetail infusion has been associated with acute pancreatitis. In a case report, a 56-year-old female presenting with recurrent mild acute pancreatitis every 6-7 months, previously thought to be drug-induced, discontinued ingesting horsetail infusions. The patient had a history of bilateral adrenal gland removal and was being treated for hypertension, dyslipidemia, and hormone replacement, and then self-medicated with horsetail infusions. After discontinuing horsetail infusions, there were no further recurrences of pancreatitis during a 14-month follow-up (97574).

Hepatic ...In one case report, a patient with asymptomatic hepatitis B developed symptomatic liver failure following consumption of boiled horsetail juice 500 mL daily for 2 weeks. Liver enzymes returned to normal following discontinuation of the juice (92291). It is not known if the horsetail juice was contaminated or mixed with other ingredients.

Immunologic ...Horsetail has been associated with cross-allergenicity with carrots (13577).

Renal ...There are at least 4 case reports of hyponatremia thought to be at least partially associated with horsetail consumption. In one case report, an elderly patient who had taken oral horsetail 15 mg daily for 10 years presented with hyponatremia and syndrome of inappropriate secretion of antidiuretic hormone (SIADH) secondary to reduced oral intake and nausea for the previous 2 days. Horsetail was thought to be a contributing factor. The patient's symptoms resolved after 5 days of treatment with oral sodium chloride and fluid restriction (108851).

Other ...Crude horsetail contains thiaminase, which can cause thiamine deficiency with prolonged consumption. Canadian Equisetum arvense products are required to be certified as free from thiaminase-like activity (55579,105301). In one case report, the development of autism in a child exposed to both horsetail and alcohol during pregnancy was thought to be caused by thiamine deficiency attributed to this combination (92292). However, it is not known if other genetic or environmental factors were involved in the development of this condition in utero.

(Read more about HORSETAIL)

General ...Orally and intravenously, L-carnitine is generally well tolerated.
Most Common Adverse Effects:
All routes of administration: Abdominal cramps, abdominal pain, diarrhea, gastritis, heartburn, nausea, reduced appetite, and vomiting. A fish-like body odor has also been reported.
Serious Adverse Effects (Rare):
All routes of administration: Seizures.

Cardiovascular ...According to population research, plasma L-carnitine levels are associated with increased risk of cardiovascular disease and major cardiac events (90635). However, oral supplementation with L-carnitine does not appear to be associated with an increased risk of cardiovascular disease. In fact, a meta-analysis of clinical research shows that L-carnitine supplementation is associated with a reduction in all-cause mortality, as well as ventricular arrhythmias and the development of angina and does not increase the development of heart failure or myocardial reinfarction (59037). Also, another meta-analysis suggests that L-carnitine does not affect mortality or cardiovascular outcomes in patients with a previous myocardial infarction (90630).

Dermatologic ...Orally, L-carnitine has been reported to cause skin rash in a small number of cases (16105,91724). Two patients in a hair growth study using topical carnitine reported mild itching and increased dandruff, while a third reported strong itching with reddish bumps and a burning sensation (58390). When a specific formulation containing L-carnitine, licochalcone, and 1,2-decanediol was applied to the face, mild skin dryness and tightness was reported by 12% of volunteers, compared with 4% to 8% of those in the vehicle-only control group (26493).

Gastrointestinal ...Orally and intravenously, L-carnitine has been associated with nausea, epigastric discomfort, vomiting, abdominal cramps, heartburn, gastritis, anorexia, and diarrhea (3616,3624,59030,95069,95070,101562,107410,111870,111887,111891). Orally, diarrhea or colitis symptoms (1433,3630,16105,16107,16111,23437,58523,58554,59020,90623), nausea and abdominal pain (16105,16106,26499,58169,58392,58554,90623,90634), indigestion (26703), and constipation (58523) have been reported in various clinical trials.

Hematologic ...In one case report, L-carnitine 990 mg twice daily was started in a female presenting to hospital with valproic acid toxicity. Blood phosphorous levels subsequently fell from 2.3 mg/dL to 1.3 mg/dL over 4 days. After discontinuation of L-carnitine, blood phosphorus levels increased to 1.8 mg/dL. The authors suggested that the role of L-carnitine in improved protein metabolism may play a role in the declining levels of phosphorous in the blood and increased risk of hypophosphatemia (90628).

Neurologic/CNS ...Orally or intravenously, L-carnitine has been associated with seizures (3616). Orally, use of L-carnitine in clinical trials has resulted in headache, although this event is rare (58554,95070,111891). L-carnitine may also cause agitation (95070).

Other ...Orally or intravenously, L-carnitine has been associated with a fish-like body odor (1433,3616,58166,59854,90623). One of its metabolites, trimethylamine N-oxide, can cause the urine, breath, and sweat to have a fishy odor (12756,58664).

(Read more about L-CARNITINE)

General ...Orally, a thorough evaluation of safety outcomes for raspberry ketone has not been conducted. Structurally, raspberry ketone resembles synephrine, a known stimulant agent.

Cardiovascular ...Structurally, raspberry ketone resembles synephrine, a known stimulant agent. Although not well studied in humans, stimulant-related side effects are possible. Orally, cases of heart palpitations, tachycardia, elevated blood pressure, coronary vasospasm are reported after taking raspberry ketone (17961,112386,112400). In one case report, pulseless electrical activity arrest followed by resistant polymorphic ventricular tachycardia occurred in a patient taking raspberry ketone. The arrhythmia resolved after numerous defibrillation shocks and placement of a temporary transvenous pacemaker with overdrive pacing (112386). In another case report, 5 episodes of ST elevation occurred over 2 days following ingestion of raspberry ketone (112400).

Neurologic/CNS ...Structurally, raspberry ketone resembles synephrine, a known stimulant agent. Although not well studied in humans, stimulant-related side effects are possible. Two case reports describe symptoms of sweating, diarrhea, and feelings of shakiness after oral use of raspberry ketone (17961,112400).

(Read more about RASPBERRY KETONE)