nutraMetrix Cognitive Formula with Huperzine by Market America, Inc.

POSSIBLY EFFECTIVE

• Age-related cognitive decline. Oral acetyl-L-carnitine may improve age-related cognitive decline. Details: Clinical research shows that taking acetyl-L-carnitine 1500-2000 mg daily for 3 months seems to improve some measures of cognitive function and memory in elderly people with age-related cognitive decline (42,3600,3601).
• Age-related fatigue. Oral acetyl-L-carnitine may improve age-related physical and mental fatigue. Details: One clinical trial shows that taking acetyl-L-carnitine 2 grams twice daily for 180 days reduces physical fatigue by 52% and mental fatigue by 43%, compared with only 4% and 8%, respectively, for elderly patients taking placebo. Fatigue after exercise is also reduced by 51% in those taking acetyl-L-carnitine, compared with only 4% in those taking placebo (58375).
• Alcohol use disorder. Intravenous acetyl-L-carnitine may reduce cravings and other symptoms of withdrawal during alcohol detoxification. It is unclear if oral acetyl-L-carnitine is beneficial for managing withdrawal or complications of alcohol use disorder. Details: Clinical research in adults with alcohol use disorder who are in withdrawal shows that acetyl-L-carnitine 1-3 grams daily, administered as a slow intravenous infusion over 3-4 hours for 10 days, followed by 3 grams daily orally for an additional 80 days, improves cravings, the inability to feel pleasure (anhedonia), and melancholic symptoms and increases the time to the first drink when compared with placebo. However, most symptom improvement appears to occur during the first week, so it is unclear if taking acetyl-L-carnitine 3 grams daily orally for an additional 80 days is beneficial (90766,90767). One small clinical trial in adults with chronic alcohol use disorder and cognitive impairment shows that taking acetyl-L-carnitine 2 grams daily for 90 days seems to improve memory and visuospatial capacity when compared with placebo (1589).
• Alzheimer disease. Oral acetyl-L-carnitine may slow the progression of Alzheimer disease and improve some measures of cognitive function. Details: Clinical research shows that taking acetyl-L-carnitine 1.5-3 grams daily for 3-12 months might slow the rate of Alzheimer disease progression and improve memory, some measures of cognitive function, and behavioral performance. It is more likely to show some effect in those with early-onset Alzheimer disease who are less than 66 years of age and have a faster rate of disease progression and mental decline (1594,1595,1596,1597,1598,1599,9105,10391). It is unclear how acetyl-L-carnitine compares with prescription medications.
• Depression. Oral acetyl-L-carnitine may reduce symptoms of depression, with comparable effects to conventional antidepressants, in patients with dysthymia and depression. It may be most effective in elderly patients and at higher doses. Details: Several clinical trials addressing the use of acetyl-L-carnitine in elderly patients with dysthymia and depression have been conducted (3602,3603,3604). A meta-analysis of these and other studies, all conducted in Europe, shows that taking acetyl-L-carnitine 1-4 grams daily for 3-24 weeks moderately reduces depressive symptoms when compared with placebo, and appears to have similar effects as conventional antidepressants. Acetyl-L-carnitine seems to be most effective when used at higher dosages. Duration of follow-up and baseline symptoms do not appear to influence results (95065).
• Diabetic neuropathy. Oral acetyl-L-carnitine may reduce pain in patients with diabetic neuropathy when taken at doses of at least 2-3 grams daily. It is unclear if oral acetyl-L-carnitine can improve nerve conduction velocity in these patients. Details: Although most clinical research evaluating acetyl-L-carnitine for use in diabetic neuropathy has shown benefit, this evidence is of overall low quality. A meta-analysis shows that taking acetyl-L-carnitine 2-3 grams daily for up to 12 months modestly reduces pain scores by about 15 points on a 100-point visual analog scale, while lower doses of 1.5 grams daily improve pain scores to a similar extent as placebo. Some research included in this analysis shows that acetyl-L-carnitine seems to increase nerve fibers, regenerate nerve fiber clusters, and improve vibratory sensations. In two studies, vibration sensation improved after 12 months when compared with placebo, but numerical data are lacking (102126). Other clinical research shows that taking acetyl-L-carnitine 1000 mg 2-3 times daily decreases pain within 6 months. Acetyl-L-carnitine seems to be most effective for reducing pain in patients with a shorter duration of diabetes and in patients with poorly controlled type 2 diabetes. Some research shows that taking acetyl-L-carnitine 500 mg (Liaoning Haisike Pharmaceutical Co. Ltd.) three times daily for 24 weeks is as effective as methylcobalamin 0.5 mg three times daily for improving electrophysiological parameters and symptoms as measured by the Neuropathy Disability Score (95067,102126). However, research on the use of acetyl-L-carnitine to improve nerve conduction velocity in patients with diabetic neuropathy is conflicting (1593,12743,12753,13007,95067).
• Male infertility. Oral acetyl-L-carnitine, taken in combination with L-carnitine, may increase sperm motility in males with infertility. It is unclear if oral acetyl-L-carnitine alone can improve sperm function or pregnancy outcomes. Details: Although some research disagrees (111861), taking acetyl-L-carnitine in combination with L-carnitine, usually in doses of 1 gram and 2 grams, respectively, daily for 3-6 months seems to increase sperm motility in males with infertility of various etiologies. The evidence related to the effect of this combination on sperm count and morphology is mixed (12352,58182,58194,58469,101560,107394,111459,111890). However, it is unclear if taking L-carnitine increases the odds of pregnancy. One meta-analysis of randomized controlled trials shows that taking these carnitines 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). Taking acetyl-L-carnitine 500 mg and L-carnitine 1 gram twice daily after taking nonsteroidal anti-inflammatory drugs for 2 months seems to increase sperm count and motility in those with abacterial prostatovesiculoepididymitis, an inflammation of the prostate gland, seminal vesicles, and epididymis (9791). Acetyl-L-carnitine has also been evaluated in combination with other ingredients. One study shows that taking acetyl-L-carnitine 50 mg in combination with L-carnitine 150 mg, L-arginine 1660 mg, and Panax ginseng 200 mg daily for 3 months increases sperm motility and sexual satisfaction in those with asthenospermia 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 treatment with prulifloxacin alone in patients with chronic prostatitis due to Chlamydia trachomatis infection (59006). Other small and preliminary Iclinical studies have investigated the effects of a specific combination product providing acetyl-L-carnitine 500 mg twice daily for 6 months, along with 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.

POSSIBLY INEFFECTIVE

• Chemotherapy-induced peripheral neuropathy. The evidence related to the effect of oral acetyl-L-carnitine on symptoms of chemotherapy-induced peripheral neuropathy is mixed. Some research shows that it may actually worsen symptoms. Details: High quality clinical research in females treated with taxane-based therapy for early-stage breast cancer shows that taking acetyl-L-carnitine 1000 mg three times daily for 24 weeks does not improve symptoms of neuropathy when compared with placebo. In fact, acetyl-L-carnitine treatment may actually make symptoms worse in some patients, with worsened symptoms persisting for up to at least 2 years (90758,96938,111882). Also, a small clinical trial in patients with multiple myeloma receiving bortezomib, doxorubicin, and dexamethasone shows that taking acetyl-L-carnitine 1.5 grams daily does not reduce symptoms of peripheral neuropathy when compared with not taking acetyl-L-carnitine (90756). A small clinical trial in patients with ovarian cancer or castration-resistant prostate cancer receiving sagopilone shows that taking acetyl-L-carnitine 1000 mg every three days appears to reduce the more severe symptoms of peripheral neuropathy; however, the overall incidence or duration of peripheral neuropathy is not reduced when compared with placebo (90757). Some research disagrees. One clinical trial in patients with taxoid-related neuropathy shows that taking acetyl-L-carnitine3 grams daily for 8 weeks modestly improves the severity of neuropathy by at last one grade in 51% of patients compared with 24% of those taking placebo. Functional improvement was also modestly improved (111862). Based on the available research, the American Society of Clinical Oncology strongly discourages the use of acetyl-L-carnitine for the prevention of chemotherapy-induced peripheral neuropathy, noting that the harms outweigh the potential benefits (104168).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related testosterone deficiency. Oral acetyl-L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One clinical study in older males shows that taking acetyl-L-carnitine 2 grams, in combination with propionyl-L-carnitine 2 grams, daily for 6 months seems to attenuate symptoms of androgen decline. The combination appears to be similar to testosterone for improving sexual dysfunction, depression, and fatigue (12353). It is unclear if these findings are due to acetyl-L-carnitine, propionyl-L-carnitine, or the combination.
• Aging skin. Although there has been interest in using oral acetyl-L-carnitine for aging skin, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Amenorrhea. Although there has been interest in using oral acetyl-L-carnitine for amenorrhea, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). It is unclear if oral acetyl-L-carnitine is beneficial in patients with ALS. Details: One small clinical trial in patients with ALS shows that taking acetyl-L-carnitine 1000 mg three times daily for 48 weeks, along with riluzole 50 mg twice daily, reduces the number of patients who lose self-sufficiency by about 17%, increases patient survival by a median of 23 months, and improves some measures of physical function when compared with riluzole alone (90755).
• Antiretroviral toxic neuropathy. Small clinical studies suggest that oral acetyl-L-carnitine may modestly improve symptoms in patients with antiretroviral toxic neuropathy. It is unclear if intramuscular or intravenous acetyl-L-carnitine is beneficial in patients with this condition. Details: Small clinical trials show that taking acetyl-L-carnitine 1000-1500 mg twice daily for up to 33 months might relieve symptoms of distal symmetrical polyneuropathy caused by antiretroviral treatment in HIV-positive patients (12745,58342). Also, a small, uncontrolled clinical study shows that intramuscular or intravenous administration of acetyl-L-carnitine 500-1000 mg daily for 3 weeks reduces pain intensity when compared to baseline in some HIV-positive patients receiving antiretroviral therapy (12747). However, another clinical study shows that intramuscular acetyl-L-carnitine 500 mg twice daily for 14 days does not reduce pain when compared with placebo (58342).
• Athletic performance. Although there has been interest in using oral acetyl-L-carnitine for athletic performance, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Attention deficit-hyperactivity disorder (ADHD). Small clinical trials suggest that oral acetyl-L-carnitine is not beneficial in children with ADHD. Details: One small clinical trial in children and adolescents with ADHD shows that taking acetyl-L-carnitine 1-3 grams daily, based on body weight, in two divided doses along with methylphenidate 20-30 mg daily for 3 weeks does not reduce symptoms of ADHD when compared with methylphenidate alone (90754). Based on this and another small trial, Guidelines from The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce state that acetyl-L-carnitine in doses of 1-3 grams daily is not recommended for adjunctive or monotherapy use for ADHD in children (110318).
• Bell palsy. Although there has been interest in using oral acetyl-L-carnitine for Bell palsy, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Bipolar disorder. Oral acetyl-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 type I or type II bipolar disorder shows that taking acetyl-L-carnitine 1000 mg plus alpha-lipoic acid 600 mg up to three times daily for 12 weeks does not improve depression when compared with placebo (90441).
• Cancer-related fatigue. Although there has been interest in using oral acetyl-L-carnitine for cancer-related fatigue, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Carpal tunnel syndrome. It is unclear if oral acetyl-L-carnitine is beneficial in patients undergoing surgery for carpal tunnel syndrome. Details: A small clinical study in adults undergoing carpal tunnel release surgery shows that taking acetyl-L-carnitine 3000 mg daily for 2 months postoperatively does not improve nerve regeneration or functional recovery when compared with placebo (100349). However, this study may have been inadequately powered to detect a difference between groups. Acetyl-L-carnitine has also been investigated in combination with other ingredients. In patients with mild to moderate symptoms awaiting carpal tunnel release, preliminary clinical research shows that taking acetyl-L-carnitine as part of a multi-ingredient formulation for 60 days reduces pain by 31%, but does not improve function, when compared with no treatment. The formulation provided a total of 600 mg twice daily of acetyl-L-carnitine with alpha-lipoic acid, phosphatidylserine, curcumin, thiamine, riboflavin, and vitamins C, E, B6, and B12 (111702).
• Cataracts. Although there has been interest in using oral acetyl-L-carnitine for cataracts, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Chronic fatigue syndrome (CFS). It is unclear if oral acetyl-L-carnitine is beneficial in patients with CFS. Details: Preliminary clinical research in patients with CFS shows that taking acetyl-L-carnitine 2 grams daily for 6 months improves general fatigue in up to 59% of patients when compared with baseline. The combination of acetyl-L-carnitine and propionyl-L-carnitine appears to be less effective than either supplement alone, with only 37% of patients taking this combination achieving improvement when compared with baseline (11788).
• Diabetes. It is unclear if oral acetyl-L-carnitine improves glycemic control in people with type 2 diabetes. Details: Clinical research in patients with type 2 diabetes, hypertension, and dyslipidemia shows that taking acetyl-L-carnitine 1 gram twice daily for 6 months does not improve blood glucose levels, glycated hemoglobin, fasting insulin levels, insulin resistance, or glucose disposal rate when compared with placebo. Most patients were already taking one or more antidiabetes drug, as well as medication for hypertension and dyslipidemia (96937). It is unclear if acetyl-L-carnitine improves glycemic profile in patients with uncontrolled diabetes.
• Down syndrome. Although there has been interest in using oral acetyl-L-carnitine for Down syndrome, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Dyslipidemia. It is unclear if oral acetyl-L-carnitine reduces lipid levels in adults with dyslipidemia. Details: Clinical research in patients with dyslipidemia, type 2 diabetes, and hypertension shows that taking acetyl-L-carnitine 1 gram twice daily for 6 months does not improve cholesterol, triglycerides, or lipoprotein(a) levels when compared with placebo. All patients were taking statins prior to treatment with acetyl-L-carnitine, and most were receiving medication for hypertension and diabetes (96937). It is unclear if acetyl-L-carnitine is beneficial in patients not taking statins.
• Fibromyalgia. It is unclear if oral and/or intramuscular acetyl-L-carnitine can improve symptoms of fibromyalgia. Details: One clinical study in patients with fibromyalgia shows that taking acetyl-L-carnitine 1000 mg daily orally plus acetyl-L-carnitine 500 mg daily intramuscularly for 2 weeks, followed by acetyl-L-carnitine 1500 mg daily orally for 8 weeks, reduces muscle pain and improves mood, general health, and quality of life when compared with placebo (90768). A smaller clinical study in patients with fibromyalgia shows that taking acetyl-L-carnitine 500 mg three times daily for 12 weeks improves quality of life (physical) scores and symptoms of depression, but not pain, anxiety, or quality of life (mental) scores when compared with baseline (90761). The validity of these findings is limited by the lack of a comparator group. Acetyl-L-carnitine has also been investigated in combination with other ingredients. Clinical research shows that taking acetyl-L-carnitine 500 mg and palmitoylethanolamide (PEA) 600 mg twice daily for 12 weeks increases the proportion of patients with at least a 30% reduction in pain by 86% when compared with not taking this combination. There was also a modest improvement in the overall assessment of status. All patients were on stable treatment with duloxetine and pregabalin for 3 months prior to the initiation of acetyl-L-carnitine and PEA, and this treatment continued throughout the study (111901).
• Fragile X syndrome. Small clinical studies suggest that oral acetyl-L-carnitine is not beneficial in children with fragile X syndrome. Details: Two small clinical studies in children with fragile X syndrome shows that acetyl-L-carnitine 20-50 mg/kg daily for one year does not improve intellectual function when compared with placebo. Also, while it may reduce hyperactive behavior in these patients based on parent assessment, it does not appear to reduce hyperactive behavior based on teacher assessment (9956,93063).
• Frailty. It is unclear if oral acetyl-L-carnitine prevents frailty. Details: Clinical research in pre-frail older adults shows that taking acetyl-L-carnitine 1.5 grams twice daily for 3 months modestly improves cognition and the distance walked in 6 minutes when compared with taking placebo (111889). It is unclear whether taking acetyl-L-carnitine is beneficial for frailty treatment or prevention.
• Hepatic encephalopathy. Small clinical studies suggest that oral acetyl-L-carnitine may not improve quality of life or fatigue in patients with hepatic encephalopathy due to cirrhosis. Details: The benefits of acetyl-L-carnitine in the management of hepatic encephalopathy due to cirrhosis are unclear (58922,58949,59002,90759). A meta-analysis of the available clinical research shows that taking acetyl-L-carnitine 2 grams twice daily for 90 days does not improve quality of life or fatigue in this population when compared with placebo. However, major clinical outcomes, such as all-cause mortality, days of hospitalization, and serious adverse events, have not been evaluated. Additionally, the validity of these findings is limited by the small size, high risk for bias, and heterogeneity of the included studies (100350).
• Hypertension. It is unclear if oral acetyl-L-carnitine lowers blood pressure in adults with hypertension. Details: Clinical research in patients with hypertension, type 2 diabetes, and dyslipidemia shows that taking acetyl-L-carnitine 1 gram twice daily for 6 months does not improve systolic or diastolic blood pressure when compared with placebo. Most patients were already being treated with antihypertensive drugs prior to treatment with acetyl-L-carnitine, in addition to medications for dyslipidemia and diabetes (96937). It is unclear if acetyl-L-carnitine reduces blood pressure in patients with uncontrolled hypertension.
• Infertility. Although there has been interest in using oral acetyl-L-carnitine for infertility in females, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Lyme disease. Although there has been interest in using oral acetyl-L-carnitine for Lyme disease, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Multiple sclerosis-related fatigue. It is unclear if oral acetyl-L-carnitine is beneficial in patients with multiple sclerosis-related fatigue. Details: One small clinical study in patients with multiple sclerosis shows that taking acetyl-L-carnitine 1 gram twice daily for one month reduces fatigue by approximately 25% when compared with placebo (90760).
• Obesity. Although there has been interest in using oral acetyl-L-carnitine for obesity, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Peripheral neuropathy. Although there has been interest in using oral acetyl-L-carnitine for peripheral neuropathy, there is insufficient reliable information about the clinical effects of acetyl-L-carnitine for this purpose.
• Peyronie disease. A small clinical study suggests that oral acetyl-L-carnitine may modestly improve symptoms of Peyronie disease. Details: One small clinical trial in patients with acute and early chronic Peyronie disease shows that taking acetyl-L-carnitine 1 gram twice daily for 3 months reduces pain and slows disease progression when compared with tamoxifen 20 mg twice daily (10076).
• Polycystic ovary syndrome (PCOS). It is unclear if acetyl-L-carnitine is beneficial in patients with PCOS. Details: A clinical study in patients with PCOS shows that taking acetyl-L-carnitine 1.5 grams, in combination with metformin and pioglitazone, twice daily for 12 weeks improves menstrual irregularity and insulin resistance when compared with baseline. The lack of statistical comparison to placebo, as well as the combined use with metformin and pioglitazone, limits the validity of these findings (107396).
• Schizophrenia. It is unclear if oral acetyl-L-carnitine is beneficial in patients with schizophrenia. Details: A very small, open-label clinical study in patients with schizophrenia who partially responded to clozapine therapy shows that taking acetyl-L-carnitine 1 gram daily, in combination with clozapine 300-600 mg daily, for 12 weeks reduces positive symptoms of schizophrenia, but not cognitive function or other clinical symptoms, when compared with baseline (95063). The validity of these findings is limited by the lack of a comparator group.
• Sciatica. It is unclear if oral acetyl-L-carnitine is beneficial in patients with sciatica. Details: One small clinical trial in patients with sciatica secondary to a herniated disc shows that taking acetyl-L-carnitine (Nicetile, SigmaTau Ind. Farm. Riunite SpA,) 1180 mg daily for 60 days decreases the use of analgesics when compared with baseline. However, acetyl-L-carnitine appears to be less effective than alpha-lipoic acid (Byodiniral 300 QR, MDM SpA,) 600 mg daily for reducing lower limb pain and the use of analgesics (21671).
• Stroke. It is unclear if oral acetyl-L-carnitine is beneficial following a stroke. Details: Clinical research in patients with an acute ischemic stroke given routine care shows that oral or nasogastric acetyl-L-carnitine 1 gram three times daily for 3 days modestly improves stroke impairment and overall function 3 months after the stroke when compared with taking placebo. The proportion of patients taking acetyl-L-carnitine with no symptoms or obvious disability at 3 months was 53%, compared with 29% of patients taking placebo. The patients in this study were not candidates of reperfusion therapy and initiated acetyl-L-carnitine within 24 hours of the stroke (111894).
• Toxin-induced liver damage. Oral acetyl-L-carnitine has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients being treated with anti-tuberculosis drugs shows that taking acetyl-L-carnitine 250 mg, along with coenzyme Q10 and alpha-lipoic acid, twice daily for 2 weeks reduces the risk of drug-induced liver injury by 73% when compared with placebo (107445). It is unclear if these findings are due to acetyl-L-carnitine, other ingredients, or the combination. More evidence is needed to rate acetyl-L-carnitine for these uses.

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POSSIBLY EFFECTIVE

• Diabetic neuropathy. Oral or intravenous alpha-lipoic acid 600-1800 mg daily seems to improve symptoms of peripheral neuropathy in patients with diabetes. Its benefits in patients with cardiac autonomic neuropathy are unclear. Details: Several clinical studies show that taking alpha-lipoic acid, either alone or in combination with gamma-lipoic acid, superoxide dismutase, or vitamin B12, seems to improve neuropathic sensory symptoms such as burning, pain, numbness, and prickling of the feet and legs, as well as objective measures such as ratings of neurological deficit and disability. Symptom improvement seems to occur within 3 to 5 weeks of oral or intravenous dosing (3540,3541,3557,3868,10148,12106,20473,20475,20478,20480)(20481,20484,20488,90447,103333,111429,111703,113894). A meta-analysis of 10 clinical studies in adults with diabetic polyneuropathy shows that taking alpha-lipoic acid 600-1800 mg daily for 3 weeks to 2 years reduces the incidence, severity, and frequency of sensory symptoms and improves measures of impairment and neurological disability but does not improve vibration perception threshold or measures of nerve conduction when compared with placebo (111703). Additionally, a similar meta-analysis of 3 clinical studies shows that taking alpha-lipoic acid 600 mg daily improves neuropathy symptoms as assessed with the Total Symptom Score (TSS) when compared with placebo (113894). However, another meta-analysis of 6 studies in patients with type 1 or 2 diabetes, that includes some of the same studies, shows that giving alpha-lipoic acid 600-1800 mg daily orally or intravenously for 3-8 weeks does not improve neuropathic pain when compared with placebo (112937). Likewise, a Cochrane systematic review of 3 clinical studies in patients with type 1 or 2 diabetes shows that alpha-lipoic acid given intravenously and orally has little to no benefit on neuropathy symptoms after 6 months as assessed with the TSS or on impairment as assessed with the Neuropathy Impairment Score-Lower Limbs when compared with placebo (113897). Alpha-lipoic acid has also been evaluated in conjunction with other treatments for diabetic neuropathy. Meta-analyses of 2-9 clinical studies in patients with diabetic neuropathy shows that intravenous alpha-lipoic acid 600 mg daily in combination with vitamin B12 and epalrestat for 3-8 weeks improves sensory and motor nerve conduction velocity and vibration perception thresholds in the lower limbs when compared with control groups receiving either conventional therapy or the vitamin B12 and epalrestat combination alone (113896). It is unclear if these effects are due to alpha-lipoic acid, other ingredients, or the combination. Additionally, all studies were conducted in China and so it is unclear if results can be extrapolated to other geographic regions and populations. Across the various studies, alpha-lipoic acid 600-1800 mg taken by mouth daily in one to three divided doses has been used (3540,3541,3868,20475,20478,103333,111429,113897). A specific combination product containing alpha-lipoic acid 600 mg and superoxide dismutase 140 IU (ALA600 SOD, Alfa Wassermann) has also been used (20488). Intravenously, alpha-lipoic acid 600 mg and 1200 mg daily have been used (3540,3541,3557,10148,20480,20481,20484,113897). In one study, a specific product (Thiotacid, Eva Pharma) was used (103333). However, some preliminary clinical research shows that lower doses of alpha-lipoic acid are ineffective for improving nerve conduction velocity or subjective complaints of neuropathy (3869,20479,20482,20486,20487). Also, although there is some preliminary evidence that taking alpha-lipoic acid improves nerve function indices, such as Valsalva maneuver, Ewing's tests, or electrocardiogram measurements in patients with a specific type of diabetic neuropathy called cardiac autonomic neuropathy, taking alpha-lipoic acid orally does not improve clinical symptoms (3542,20483,20485,96223,107892).
• Hyperlipidemia. Oral alpha-lipoic acid seems to reduce levels of total and low-density lipoprotein (LDL) cholesterol in certain populations. However, it is unclear whether alpha-lipoic acid is clinically beneficial in patients with hyperlipidemia. Details: A meta-analysis of 11 clinical trials shows that taking alpha-lipoic acid 300-1200 mg daily for up to 16 weeks decreases total cholesterol by 10 mg/dL and LDL cholesterol by 9 mg/dL, but does not seem to improve high-density lipoprotein (HDL) cholesterol or triglycerides, when compared with placebo (100709). In addition, in a large group of generally healthy adults, taking alpha-lipoic acid 800-1200 mg for 4 years reduces levels of total and LDL cholesterol, as well as triglycerides, when compared with baseline. The 1200 mg daily dose was more effective than the 400 mg daily dose (104650). A meta-analysis of clinical research in various patient populations shows that taking oral alpha-lipoic acid 300-1200 mg daily for 2-16 weeks decreases levels of total cholesterol by 11 mg/dL, LDL cholesterol by 11 mg/dL, and triglycerides by 31 md/dL when compared with placebo. It is unclear whether dose or treatment duration affect these outcomes (107885). These findings are limited by the high heterogeneity of the included studies and patient populations. One clinical study in adults with gestational diabetes, most of whom had elevated cholesterol levels at baseline, shows that taking oral alpha-lipoic acid (Puritan's Pride) 100 mg daily for 8 weeks reduces triglycerides, but does not improve levels of total, HDL, or LDL cholesterol, when compared with placebo (107890). The validity of this study is limited due to short duration of treatment. While many patients in these studies had elevated lipid levels at baseline, none of the studies specifically evaluated patients with hyperlipidemia. Thus, the benefits of alpha-lipoic acid in these patients is unclear.
• Obesity. Most research shows that oral alpha-lipoic acid seems to improve weight loss by a small amount. Details: While individual clinical studies show mixed results (21674,97630,100710,103327,103334), meta-analyses of clinical research show that taking alpha-lipoic acid 300-1800 mg daily for 2-48 weeks can modestly reduce body weight by 0.7-2.3 kg and body mass index (BMI) by up to 0.5 kg/m2 when compared with placebo in overweight individuals or patients with obesity. The magnitude of these improvements are not dependent on the dose or duration of treatment (96231,96232,103332,111294). While these improvements are statistically significant, they may not be clinically meaningful. In addition, a network meta-analysis of randomized controlled trials in adults with obesity shows that taking alpha-lipoic acid 300-600 mg orally daily for 8-10 weeks improves some markers of insulin resistance, but not blood pressure or cholesterol levels (111294). Taking alpha-lipoic acid might also reduce body weight in overweight children or children with obesity. In adolescents aged 10-17 years, clinical research shows that taking alpha-lipoic acid 300 mg twice daily for 3 months reduces body weight by 3.2 kg when compared with placebo. However, there was no effect on blood lipids or fasting blood glucose (103330). Also, a small clinical study in children 8-16 years of age shows that taking alpha-lipoic acid (Tiobec 800, Laborest) 800 mg daily for 12 weeks does not improve body weight, BMI, blood pressure, blood lipids, glycemic control, insulin resistance, or endothelial function when compared with placebo (100708). However, this study may have been inadequately powered to detect a difference in many of these outcomes.

POSSIBLY INEFFECTIVE

• Alcohol-related liver disease. Oral alpha-lipoic acid does not seem to improve liver function in patients with alcohol-related liver disease. Details: Taking alpha-lipoic acid orally 300 mg daily for up to 6 months does not appear to improve liver function or reduce liver damage when compared with placebo in patients with alcohol-related liver disease (3880,21678).
• Altitude sickness. Oral alpha-lipoic acid, in combination with vitamins C and E, does not seem to be beneficial for altitude sickness prevention or treatment. Details: Clinical research in healthy volunteers ascending to 5200 meters shows that taking alpha-lipoic acid 600 mg in combination with vitamin C 1 gram and vitamin E (alpha-tocopherol) 400 IU in four divided doses daily, beginning on the day of travel to high altitude and continuing for 2 weeks thereafter, does not prevent the occurrence nor decrease the severity of altitude sickness when compared with placebo (20499).
• Contrast induced nephropathy. Oral alpha-lipoic acid does not seem to prevent nephropathy after undergoing coronary angiography. Details: In diabetic patients at low risk for contrast induced nephropathy, alpha-lipoic acid (Thioactacid 600 mg RH, MEDA Manufacturing GmbH) 600 mg taken 30 minutes prior to and 24 and 48 hours after undergoing coronary angiography, with or without standard hydration therapy, does not reduce the risk of contrast induced nephropathy when compared with standard hydration therapy (90442). In addition, treatment with alpha-lipoic acid 600 mg orally every 8 hours beginning the afternoon prior to angiography and continuing for 2 days does not attenuate the maximum increase in serum creatinine or reduce the incidence of contrast induced nephropathy in most patients when compared with standard hydration therapy alone (90446).
• Diabetes. Oral or intravenous alpha-lipoic acid does not seem to be beneficial for glycemic control in patients with type 2 diabetes. Details: Although some conflicting findings from individual studies exist, the overall evidence does not support the use of oral or intravenous alpha-lipoic acid for improving glycemic control or insulin sensitivity in patients with type 2 diabetes (3545,3874,3875,3876,20490,20493,20494,20495,20496,90443)(90445,110118,111305). A meta-analysis of 16 small clinical studies in patients with type 2 diabetes shows that taking alpha-lipoic acid 200-1200 mg daily for up to 52 weeks leads to slight improvements in glycemic control and body weight, but these improvements are not clinically significant. When compared with placebo, alpha-lipoic acid reduced fasting blood glucose by 6 mg/dL, glycated hemoglobin (HbA1c) by 0.17%, body weight by 0.7 kg, and body mass index (BMI) by 1.1 kg/m2. While triglyceride levels were reduced by 19 mg/dL, improvements in other lipids levels and blood pressure were lacking (110118). A specific alpha-lipoic acid product administered orally or intravenously in some of these studies was Thioctacid (Asta Medica) (3874,3875,3876). Alpha-lipoic acid has also been evaluated in patients with gestational diabetes or type 1 diabetes. A small clinical study in adults with gestational diabetes shows the taking alpha-lipoic acid (Puritan's Pride) 100 mg daily for 8 weeks improves fasting blood glucose levels and insulin sensitivity but does not affect HbA1C when compared with placebo (107890). The validity of this study is limited due to its short duration, which was likely inadequate to detect a change in HbA1c. Also, one small clinical study in adolescent patients with type 1 diabetes who show signs of early stage diabetic cardiomyopathy shows that taking alpha-lipoic acid 300 mg twice daily for 4 months, in combination with insulin therapy, improves left ventricular systolic and diastolic function (90443).
• Diabetic retinopathy. Oral alpha-lipoic acid does not seem to prevent macular edema in patients with diabetic retinopathy. Details: Some research shows that taking oral alpha-lipoic acid 600 mg daily for 24 months does not improve the incidence of clinically significant macular edema when compared with placebo in patients with mild to moderate nonproliferative diabetic retinopathy (20491).
• HIV/AIDS-related dementia. Oral alpha-lipoic acid does not seem to improve cognitive impairment related to this condition. Details: Clinical research shows that taking alpha-lipoic acid 600 mg daily, alone or along with selegiline (Deprenyl), for 10 weeks may worsen HIV-associated cognitive impairment and does not affect mood or functional status when compared with placebo in patients with confirmed HIV infection and evidence of cognitive impairment (1556).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related cognitive decline. It is unclear if oral alpha-lipoic acid is beneficial for age-related cognitive decline. Details: Preliminary clinical research in elderly adults shows that taking alpha-lipoic acid 600 mg orally daily for 12 weeks does not improve cognitive function scores when compared with baseline (111303). The validity of this study is limited by the lack of a comparator group.
• Age-related macular degeneration (AMD). It is unclear if oral alpha-lipoic acid is beneficial for AMD. Details: A small clinical trial shows that taking alpha-lipoic acid (Pure Encapsulations) 1200 mg daily for 18 months does not improve visual acuity or reduce the rate of atrophy when compared with placebo in patients with advanced AMD (103335). It is unclear if alpha-lipoic acid would be beneficial in patients with less severe symptoms of AMD.
• Age-related testosterone deficiency. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A very small clinical study in males with overweight or obesity, mild erectile dysfunction, and normal to low androgen levels shows that taking a combination product containing alpha-lipoic acid 800 mg, myo-inositol, folic acid, and apple (Sinopol Forte, Laborest) increases testosterone, luteinizing hormone, and measures of erectile dysfunction but not follicle-stimulating hormone or sperm parameters when compared to baseline (111674). The validity of these findings is limited by the small sample size and lack of a comparator group, and it is unclear if these effects are due to alpha-lipoic acid, other ingredients, or the combination.
• Aging skin. Topical alpha-lipoic acid may be beneficial for aging skin. Details: A small clinical study shows that applying a cream containing alpha-lipoic acid 5% to the face twice daily for 12 weeks reduces the fine lines and roughness associated with aging of facial skin when compared with a control cream (12021).
• Alzheimer disease. It is unclear if oral alpha-lipoic acid is beneficial for this condition. Details: Some preliminary clinical research shows that taking alpha-lipoic acid 600 mg once daily in combination with standard cholinesterase inhibitors may slow cognitive decline when compared with cholinesterase inhibitors alone in some patients with Alzheimer disease (20500,90437). However, higher-quality clinical research shows that taking alpha-lipoic acid 600-900 mg daily for up to 2 years, in combination with vitamin C and vitamin E, does not affect cognitive function when compared with placebo in patients with mild to moderate Alzheimer disease (19206,20501).
• Amanita mushroom poisoning. Evidence on the use of intravenous alpha-lipoic acid for amanita mushroom poisoning is limited to anecdotal reports. Details: Intravenous alpha-lipoic acid has been used in combination with other treatments for poisoning from amanita mushroom ingestion. Its use is controversial. Reports are anecdotal, and experimental evidence does not support its effectiveness. Some researchers recommend against its use (105,1548,1549,3871,3879).
• Anthracycline cardiotoxicity. It is unclear if oral alpha-lipoic acid is effective for the prevention of anthracycline cardiotoxicity. Details: A small clinical study in patients with breast cancer receiving doxorubicin shows that taking alpha-lipoic acid 600 mg daily for 6 months does not improve ejection fraction but does decrease levels of brain natriuretic peptide (BNP), a marker of ventricular hypertrophy, when compared with placebo (110112).
• Antipsychotic-induced hyperprolactinemia. It is unclear if oral alpha-lipoic acid is effective for the prevention or treatment of antipsychotic-induced hyperprolactinemia. Details: A very small, open-label study in patients with schizophrenia shows that taking alpha-lipoic acid 600 mg daily along with conventional antipsychotic therapy for 12 weeks reduces prolactin levels by 51% when compared to baseline (110116). The validity of this finding is limited by the lack of a control group.
• Antipsychotic-induced metabolic side effects. Small clinical studies suggest that oral alpha-lipoic acid does not seem to improve antipsychotic-induced metabolic side effects in patients with schizophrenia. Details: A very small, open-label study in patients with schizophrenia shows that taking alpha-lipoic acid 600 mg daily along with conventional antipsychotic therapy for 12 weeks reduces fasting blood glucose levels by around 17 mg/dL but actually increases glycated hemoglobin (HbA1c) by 0.14% when compared to baseline. No improvements in body weight or lipid levels were reported (110116). Another small clinical study in patients with schizophrenia stabilized on antipsychotic therapy for at least 1 year shows that taking alpha-lipoic acid 100 mg daily for 16 weeks does not improve body mass index (BMI) when compared with placebo (110115).
• Aromatase inhibitor-induced arthralgia. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with estrogen receptor positive (ER+) breast cancer and aromatase inhibitor-induced arthralgia shows that taking a specific combination product (Opera, Gamfarma Srl) containing alpha-lipoic acid 240 mg, Boswellia serrata 40 mg, methylsulfonylmethane 200 mg, and bromelain 20 mg once daily for 6 months reduces arthralgia intensity when compared to baseline, with around 22% of patients having complete symptom resolution at the end of the study (109570). The validity of these findings is limited by the lack of a control group.
• Atrial fibrillation. It is unclear if oral alpha-lipoic acid is beneficial for atrial fibrillation. Details: Clinical research shows that taking alpha-lipoic acid 600 mg daily for 12 months does not reduce the recurrence of atrial fibrillation when compared with placebo in patients who underwent a catheter ablation procedure. However, there was a decrease in the need for antiarrhythmic drugs in patients receiving alpha-lipoic acid (97628).
• Back pain. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: An observational study in adults with chronic lower back pain and sciatica suggests that taking a combination of alpha-lipoic acid 800 mg, palmitoylethanolamide 600 mg, and myrrh 200 mg daily for 30 days, along with periradicular infiltrations of oxygen-ozone, is associated with resolution of pain in 17% more patients when compared with periradicular steroid infiltrations at 60 days (111308). However, it is unclear if this effect is due to alpha-lipoic acid, other ingredients, or the combination.
• Beta-thalassemia. It is unclear if oral alpha-lipoic acid is beneficial for reducing iron accumulation in beta-thalassemia major. Details: A small, crossover study in patients with beta-thalassemia major who are receiving iron chelation therapy shows that adding oral alpha-lipoic acid 600 mg before breakfast or dinner for 8 weeks reduces levels of serum ferritin when compared with placebo (107888). Serum ferritin was reduced by 104 ng/mL and 38 ng/mL in the treatment and placebo groups, respectively. The validity of this finding is limited due to the small, exploratory nature of the study.
• Bipolar disorder. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking acetyl-L-carnitine 1000 mg plus alpha-lipoic acid 600 mg up to three times daily for 12 weeks does not improve depression when compared with placebo in patients with type I or type II bipolar disorder (90441).
• Burning mouth syndrome. It is unclear if oral alpha-lipoic acid is beneficial for burning mouth syndrome. Details: A meta-analysis of nine small, low-quality clinical trials in patients with burning mouth syndrome shows that taking alpha-lipoic acid 400-800 mg daily for up to 2 months does not reduce pain intensity when compared with placebo or active controls such as multivitamins, Biotene mouth rinse, capsaicin, laser therapy, clonazepam, or pregabalin. However, in an analysis of three placebo-controlled studies, alpha-lipoic acid increased the likelihood of any burning mouth syndrome-related symptom improvement by 92% when compared with placebo (110111). Individual studies, most of which were included in the analysis, show conflicting results overall (20474,21661,21662,21663,21664,21665,21666,111427). One small clinical trial shows that taking alpha-lipoic acid 600 mg daily improves symptoms of burning mouth syndrome in patients who had never previously been treated with anxiolytics or antidepressants, but not in those who had received these prior treatments (21668). This suggests that alpha-lipoic acid may improve symptoms of burning mouth syndrome resulting from stress, but not from depression or drug-induced hyposalivation.
• Cancer. Although there is interest in using oral alpha-lipoic acid for preventing or treating cancer, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for this condition.
• Cardiovascular disease (CVD). Although there is interest in using oral alpha-lipoic acid for preventing or treating CVD, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for this condition.
• Carpal tunnel syndrome. It is unclear if oral alpha-lipoic acid is beneficial for carpal tunnel syndrome, either before or after surgery. Details: In patients with mild to moderate carpal tunnel syndrome, preliminary clinical research shows that taking alpha-lipoic acid 600 mg daily for 60 days reduces pain by a moderate amount when compared with not taking alpha-lipoic acid, but with no effect on functionality (103328). In patients with neuropathic pain due to carpal tunnel syndrome, giving alpha-lipoic acid 600 mg intravenously daily for 30 days, then 600 mg orally daily for 60 days, decreases pain on a visual analog scale, and improves functionality when compared with oral alpha-lipoic acid alone, or no treatment (112938). Alpha-lipoic acid has also been studied in combination with other ingredients. One study shows that taking a combination of alpha-lipoic acid 600 mg and gamma-linolenic acid 360 mg for 90 days improves functional scores and subjective symptom scores when compared to baseline (21653). The validity of this finding is limited by the lack of a comparator group. Another clinical study in adults with mild to moderate carpal tunnel syndrome shows that taking a combination product containing alpha-lipoic acid, acetyl-L-carnitine, phosphatidylserine, turmeric, and vitamins C, E, B1, B2, B6, and B12 twice daily for 60 days reduces symptom severity and pain but does not improve measures of hand and wrist function when compared with control (111702). The validity of these effects is limited by a lack of blinding. The study may also be inadequately powered to detect a difference between groups. Additionally, it is unclear if the effects are due to alpha-lipoic acid, other ingredients, or the combination. Alpha-lipoic acid has also been evaluated in patients who have undergone carpal tunnel release surgery. Taking alpha-lipoic acid 600 mg daily for 40 days starting immediately after surgery does not improve the rate of nerve recovery when compared with placebo, although it seems to reduce the occurrence of post-operative pillar pain, which is a common complication of carpal tunnel release surgery (96233).
• Cataracts. Although there is interest in using oral alpha-lipoic acid for cataracts, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for this condition.
• Cervical dysplasia. It is unclear if oral alpha-lipoic acid is beneficial in patients with cervical dysplasia. Details: A small clinical study in patients with low-grade cervical intraepithelial neoplasia shows that taking alpha-lipoic acid 600 mg daily for 3 months reduces the proportion of patients with intraepithelial neoplasia by 95% when compared with placebo (110113).
• Chemotherapy-induced peripheral neuropathy. There is conflicting evidence regarding the effectiveness of oral alpha-lipoic acid for the prevention of chemotherapy-induced peripheral neuropathy. Details: One clinical study shows that taking alpha-lipoic acid 600 mg three times daily for 24 weeks during treatment with cisplatin or oxaliplatin does not affect the symptoms or severity of chemotherapy-induced peripheral neuropathy when compared with placebo (90439). However, another small clinical study in patients with breast cancer receiving paclitaxel shows that taking alpha-lipoic acid 600 mg daily for 6 months reduces the severity of peripheral neuropathy when compared with placebo (110112). The reason for this disparate finding is unclear, but it may be due to differences in chemotherapy regimens. Alpha-lipoic acid has also been evaluated in combination with other ingredients. A small clinical study shows that taking a specific product (Opera, Gamfarma s.r.l.) containing alpha-lipoic acid 240 mg, methylsulfonylmethane (MSM) 200 mg, Boswellia serrata 40 mg, and bromelain 20 mg daily for 12 weeks reduces overall pain when compared to baseline in adults with chemotherapy-induced peripheral neuropathy (96449). The validity of these findings is limited by the lack of a control group. Other preliminary clinical research shows that taking alpha-lipoic acid 600 mg orally once daily and ipidacrine 20 mg orally three times daily throughout 6 paclitaxel-based chemotherapy cycles improves sensory nerve action potential parameters when compared with control (111292). It is unclear if these effects are due to alpha-lipoic acid, the other ingredients, or the combination.
• Chronic fatigue syndrome (CFS). Although there is interest in using oral alpha-lipoic acid for CFS, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for this condition.
• Chronic kidney disease (CKD). It is unclear if oral alpha-lipoic acid is beneficial for CKD. Details: Preliminary clinical research in patients with stage 2 or 3 CKD related to autosomal dominant polycystic kidney disease shows that taking alpha-lipoic acid 1.6 grams daily for 6 months has modest benefits on biochemical markers and cognitive tests when compared to control. Taking alpha-lipoic acid reduces serum glucose, insulin, C-reactive protein (CRP), and uric acid levels, and improves insulin resistance and flow-mediated dilation and cognitive test results. However, there was no effect on intima media thickness or the ankle brachial index (101867).
• Coronary artery bypass graft (CABG) surgery. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in patients undergoing elective CABG surgery shows that taking a combination of alpha-lipoic acid 100 mg, coenzyme Q10 100 mg, magnesium orotate 400 mg, and omega-3 fatty acids 300 mg three times daily, with selenium 200 mcg once daily, for up to 2 months prior and 1 month after surgery, decreases plasma troponin levels and reduces the average postoperative hospital stay by 1.2 days when compared with placebo (21651). It is unclear if this effect is due to alpha-lipoic acid, the other ingredients, or the combination.
• Coronavirus disease 2019 (COVID-19). It is unclear if oral alpha-lipoic acid is beneficial in patients with persistent loss of the sense of smell after COVID-19 infection. Details: In adults with sense of smell loss persisting for more than 3 months after COVID-19 infection, adding alpha-lipoic acid 300 mg twice daily orally for 12 weeks to olfactory training reduces the incidence of anosmia, and improves the olfactory threshold, the sense of smell measured on a visual analog scale, and the smell identification score by a similar amount to placebo (112935). Additionally, a small clinical trial in adults with persistent olfactory dysfunction and treatment refractory parosmia due to previous COVID-19 infection shows that taking alpha-lipoic acid 800 mg daily for 6 months in combination with olfactory training does not improve tests of odor threshold, detection, and identification or reduce patient-reported symptoms of parosmia when compared with olfactory training alone (113892).
• Diabetic nephropathy. When used in combination with certain conventional medications, intravenous or oral alpha-lipoic acid may improve some measures of albuminuria in patients with diabetic nephropathy. Details: Preliminary clinical research shows that intravenous alpha-lipoic acid (YantaiZhichu Pharmaceutical Co., Ltd.) 450 mg plus intravenous alprostadil 20 mcg once daily for 14 days reduces urinary albumin excretion rate by 23% and cystatin C levels by 19% when compared with alprostadil alone (96221). Patients treated with alpha-lipoic acid 600 mg intravenously plus valsartan 80 mg orally once daily for 14 days showed a 25% lower urinary albumin excretion rate and a 27% and 31% lower serum level of beta2-microglobulin and cystatin C, respectively, when compared with patients treated with valsartan alone (101866). A meta-analysis of clinical research in adults with diabetic nephropathy shows that taking oral alpha-lipoic acid 300 mg, 450 mg, or 600 mg daily in combination with oral valsartan 80 mg daily for 14 days reduces urinary albumin excretion rate, as well as levels of urinary albumin and serum beta 2-microglobulin, when compared with either valsartan or alpha-lipoic acid alone (107891). These findings are limited by the high heterogeneity of the included studies and the presence of potential publication bias. Additionally, the long-term benefits of alpha-lipoic acid are unclear. Another meta-analysis of clinical research in patients with diabetes shows that taking oral alpha-lipoic acid 600 mg daily in conjunction with other medications (e.g. antihypertensives, vitamin B6) for 3-18 months reduces levels of urine albumin, but does not improve urinary albumin excretion rate, when compared with placebo. Notably, alpha-lipoic acid alone did not affect outcomes (107886). The validity of these findings is limited by the high heterogeneity of the included studies; additionally, the quality of evidence was considered low to moderate.
• Dry eye. It is unclear if topical alpha-lipoic acid is beneficial in patients with dry eye. Details: A small clinical study in patients with diabetes and dry eye symptoms shows that application of an eye drop containing alpha-lipoic acid 0.1% and hydroxy-propyl-methylcellulose (HPMC) 0.3% three times daily for 2 months does not improve subjective or objective measures of dry eye symptoms when compared with HPMC alone (110119).
• Dysmenorrhea. It is unclear if oral alpha-lipoic acid is beneficial for dysmenorrhea. Details: Preliminary clinical research shows that taking alpha-lipoic acid 600 mg orally daily, with or without mefenamic acid 250 mg daily, for 5 days starting before menstruation reduces pain associated with moderate to severe primary dysmenorrhea by approximately 24% and 44%, respectively, when compared to baseline (101871). The validity of this finding is limited by the lack of a comparator group.
• Erectile dysfunction (ED). It is unclear if oral or intravenous alpha-lipoic acid is beneficial for ED. Details: Preliminary clinical research in males with diabetes and ED shows that intravenous alpha-lipoic acid 600 mg with alprostadil 10 mcg once daily for 14 days improves the quality and frequency of erection in 95% of patients, compared with only 81% of those taking tadalafil 5 mg orally daily (96224). It is not clear if this improvement is due to alpha-lipoic acid, alprostadil, or the combination. Another very small study in males with mild ED, overweight or obesity, and normal to low androgen levels shows that taking a combination product containing alpha-lipoic acid 800 mg, myo-inositol, folic acid, and apple (Sinopol Forte, Laborest) improves measures of erectile dysfunction when compared to baseline (111674). The validity of these finding is limited by the small sample size and the lack of a comparator group, and it is unclear if these effects are due to alpha-lipoic acid, other ingredients, or the combination.
• Fibromyalgia. It is unclear if intravenous alpha-lipoic acid is beneficial for fibromyalgia. Details: Preliminary clinical research shows that taking alpha-lipoic acid (SiSU Vita Health) 600-1800 mg daily for 4 weeks does not reduce pain intensity when compared with placebo in patients with fibromyalgia (104655). Alpha lipoic acid has also been studied as a combination therapy for fibromyalgia. Preliminary clinical research in adults with fibromyalgia shows that taking a combination of alpha-lipoic acid and pregabalin for 6 weeks does not improve pain or depression scores when compared with either product alone (111428). However, the study may have been inadequately powered to detect a difference between groups.
• Glaucoma. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with open-angle glaucoma shows that taking a combination product containing alpha-lipoic acid 100 mg, omega-3 fatty acids 2240 mg, vitamin C 180 mg, vitamin E 27.9 mg, lutein 10 mg, zeaxanthin 2 mg, zinc 15 mg, copper 1 mg, and taurine 150 mg (NuaDHA Vision, Nua Biological) orally daily for 6 months does not improve intraocular pressure when compared with baseline (111310).
• Heart failure. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with heart failure participating in a handgrip exercise shows that taking alpha-lipoic acid, vitamin E, and vitamin C reduces mean arterial pressure by about 6 mmHg and reduces vascular resistance by about 12% when compared with placebo (19219). The first dose consisted of vitamin E 200 IU, vitamin C 500 mg, and alpha-lipoic acid 300 mg. The subsequent dose consisted of vitamin E 400 IU, vitamin C 500 mg, and alpha-lipoic acid 300 mg (19219). It is unclear if these effects are due to alpha-lipoic acid, other ingredients, or the combination.
• Hemorrhoids. It is unclear if oral alpha-lipoic acid is beneficial for hemorrhoids. Details: A preliminary open-label clinical trial shows that taking alpha-lipoic acid 200 mg daily for 12 weeks decreases anal pain while sitting, pain at defecation, itching, and bleeding when compared with no treatment in patients with second- and third-degree hemorrhoids (100707). The validity of these results is limited by a lack of blinding and placebo control.
• Herniated disc. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small observational study in adults with acute lumbosacral radiculopathy secondary to lumbar disc herniation shows that taking a combination supplement containing alpha-lipoic acid 404 mg, myrrh, and palmitoylethanolamide (PEA) (Tiobec Dol, Uriach Italy Srl) twice daily for 4 weeks, along with steroids and as needed opioids, reduces pain and disability and improves physical but not mental health as it pertains to quality of life when compared with steroids and as needed opioids alone (111711). However, it is unclear if these effects are due to alpha-lipoic acid, other ingredients, or the combination.
• HIV/AIDS. It is unclear if oral alpha-lipoic acid is beneficial for patients with HIV/AIDS who are unresponsive to highly active antiretroviral therapy (HAART). Details: A small clinical study in patients who were unresponsive to HAART shows that taking alpha-lipoic acid (Alpha Lipoic Sustain 300, Jarrow Formulas) 300 mg three times daily for 6 months improves lymphocyte proliferation and whole blood glutathione levels when compared with placebo. However, there was no change in HIV RNA levels or CD4 count (21655).
• Hypertension. It is unclear if oral alpha-lipoic acid is beneficial for hypertension. Details: Clinical research in a small number of patients with mild (stage I) hypertension shows that adding alpha-lipoic acid 600 mg daily to quinapril 40 mg daily for 8 weeks does not significantly decrease blood pressure when compared with quinapril alone (21656). A meta-analysis of 11 clinical trials shows that alpha-lipoic acid lowers systolic blood pressure by a mean of about 5 mmHg, and diastolic blood pressure by a mean of about 3 mmHg, but there is significant heterogeneity between the studies. The small decrease in blood pressure is also only seen with doses of alpha-lipoic acid below 800 mg daily when given for 12 weeks or less (112934).
• Hypertriglyceridemia. Clinical studies suggest that oral alpha-lipoic acid does not reduce triglyceride levels in patients with hypertriglyceridemia, however it might be beneficial in certain populations. Details: In overweight adults with elevated triglycerides, taking alpha-lipoic acid 600 mg daily for 24 weeks does not reduce triglyceride levels when compared with placebo (103327). In addition, a meta-analysis of 11 clinical trials in patients with or without hypertriglyceridemia at baseline shows that taking alpha-lipoic acid 300-1200 mg daily for up to 16 weeks does not improve triglyceride levels when compared with placebo (100709). However, one clinical study in adults with gestational diabetes, most of whom had elevated triglyceride levels at baseline, shows that taking alpha-lipoic acid (Puritan's Pride) 100 mg daily for 8 weeks reduces triglyceride levels by 30 mg/dL, compared with an increase of 5 mg/dL in those taking placebo, a difference that was statistically significant (107890). The validity of this study is limited due to short duration of treatment.
• Impaired glucose tolerance (prediabetes). It is unclear if oral or intravenous alpha-lipoic acid is beneficial for prediabetes. Details: A small clinical study in patients with prediabetes shows that intravenous alpha-lipoic acid 600 mg daily for 2 weeks decreases postprandial plasma glucose, steady state plasma insulin, cholesterol, and fatty acid levels and increases insulin sensitivity when compared with placebo (21657). In a large group of generally healthy adults, taking alpha-lipoic acid 800-1200 mg for 4 years reduces levels of fasting plasma glucose when compared with baseline. The 1200 mg daily dose was more effective than the 400 mg daily dose (104650). While some patients in this study had prediabetes or impaired fasting glucose at baseline, the study did not specifically evaluate patients with prediabetes.
• Infertility. Although there is interest in using oral alpha-lipoic acid to increase the chance of pregnancy, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for infertility.
• Interstitial cystitis. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: In individuals with vulval pain associated with painful bladder syndrome, clinical research shows that taking a specific product containing alpha-lipoic acid 600 mg, docosahexaenoic acid 250 mg, eicosapentaenoic acid 16.67 mg, vitamin E 12 mg, vitamin D 5 mg, and magnesium 56.25 mg (ALAnerv Age; Alfa Wassermann) daily in combination with amitriptyline up to 30 mg daily for 12 weeks reduces pelvic pain between 15% to 49% more than amitriptyline alone. Also, use of the combination supplement more than doubled the number of patients with an improvement in pain during intercourse (97629). It is unclear if the benefit is associated with alpha-lipoic acid, other ingredients, or the combination.
• Lyme disease. Although there is interest in using oral alpha-lipoic acid for Lyme disease, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for this condition.
• Male infertility. Most small clinical studies suggest that oral alpha-lipoic acid might improve sperm characteristics in males with infertility. However, it is unclear whether alpha-lipoic acid improves pregnancy or live birth rates in these individuals. Details: A meta-analysis of three small clinical studies in males with infertility shows that taking alpha-lipoic acid 600 mg daily for 80-90 days improves sperm motility and increases sperm concentration and semen volume when compared with placebo (110108). More recent clinical trials in males with idiopathic asthenozoospermia or history of recurrent pregnancy loss shows that taking alpha-lipoic acid 600 mg orally daily for 80-90 days improves sperm motility, sperm concentration, and semen volume and reduces sperm DNA damage when compared with placebo (110110,111425). However, a small clinical study in males with infertility due to high levels of sperm DNA damage shows that taking alpha-lipoic acid 600 mg daily for 80 days does not improve pregnancy rate, sperm motility, sperm concentration, semen volume, or other measures of sperm health when compared with placebo (110109). Alpha-lipoic acid has also been evaluated in combination with other ingredients. A small clinical study in males with oligoasthenoteratozoospermia (OAT) shows that taking one tablet daily of a specific product (Fertiplus SOD, Idi-Pharma) containing alpha-lipoic acid, superoxide dismutase, glutathione, and other nutrients 30 days prior to IVF procedures improves the pregnancy rate from 9% of all embryo transfers pre-treatment to 45% and reduces the rate of miscarriage when compared to baseline (97627). It is unclear if the benefit is associated with alpha-lipoic acid, the other ingredients, or the combination.
• Metabolic syndrome. It is unclear if oral alpha-lipoic acid is beneficial in patients with metabolic syndrome. Details: Preliminary clinical research in adults with metabolic syndrome shows that taking alpha-lipoic acid 600 mg orally daily for 12 weeks modestly improved serum triglyceride levels, but not serum low-density lipoprotein (LDL), or high-density lipoprotein (HDL) cholesterol levels, when compared with placebo (111307). However, the study may have been inadequately powered to detect a difference between groups.
• Migraine headache. It is unclear if oral alpha-lipoic acid is beneficial in patients with migraine headaches. Details: A meta-analysis of two small, moderate-quality clinical studies in adults in Iran and Belgium with migraine shows that taking alpha-lipoic acid 600 mg daily for 3 months reduces migraine frequency by approximately 1 per month and improves migraine severity, but not migraine duration when compared with placebo (115873). However, clinical significance is unlikely. Furthermore, the validity of these results is limited by high heterogeneity across clinical studies. A small clinical study, not included in the above meta-analysis, in adults with migraine shows that taking alpha-lipoic acid 400 mg twice daily for 6 months reduces migraine frequency by at least 50% in 69% of patients and reduces the need for migraine treatment by 56% when compared to baseline, although the validity of these findings is limited by the lack of a control group (96229). Alpha-lipoic acid has also been evaluated in adolescents for migraine prophylaxis. A small open-label study in adolescents aged 10-19 years with a history of migraine shows that taking alpha-lipoic acid 300 mg with flunarizine 5 mg as prophylaxis daily for 12 weeks reduces the frequency of migraine attacks and reduces monthly migraine headache days by 9 days, but does not reduce migraine severity or measures of disability when compared with flunarizine alone. For every 3 patients treated with alpha-lipoic acid and flunarizine over flunarizine alone, 1 additional patient had a 50% or greater reduction in migraine frequency (111706). The validity of these effects is limited by a lack of blinding.
• Miscarriage. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in pregnant adults with threatened miscarriage between the 6^th and 13^th week of gestation shows that taking a specific combination product (DAV HA, Lo.Li pharma s.r.l) containing alpha-lipoic acid 100 mg, hyaluronic acid, magnesium, vitamin B6, and vitamin D daily in combination with conventional treatment of vaginal progesterone over 2 weeks of observation results in a faster resorption of the subchorionic hematoma and faster decrease of patient-reported vaginal bleeding, abdominal pain, and uterine contractions when compared with vaginal progesterone alone (113893). It is unclear if these effects are due to alpha-lipoic acid, other ingredients, or the combination. Additionally, the validity of these findings is limited by the lack of a placebo for the control group.
• Muscle strength. It is unclear if oral alpha-lipoic acid prevents a loss of muscle strength after exercise. Details: In athletes, a small clinical trial shows that taking a single dose of alpha-lipoic acid 150 mg (Athenion GmbH) after an intensive load protocol does not prevent loss of leg strength approximately 24 hours later when compared with placebo. However, taking the same dose for 2 days, followed by 300 mg daily during a 6-day training protocol, results in the maintenance of leg strength, compared with a loss in those taking placebo (104652).
• Neck pain. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that taking a combination of alpha-lipoic acid 600 mg plus superoxide dismutase 140 IU once daily for 2 months, along with physiotherapy, reduces chronic neck pain in approximately 50% more patients when compared with physiotherapy alone (90440).
• Neuropathic pain. It is unclear if oral alpha-lipoic acid is beneficial in patients with neuropathic pain. Details: In patients with peripheral neuropathies, taking alpha-lipoic acid orally, up to 1800 mg daily for 6 weeks, is less effective for reducing pain intensity scores and improving quality of life than pregabalin, taken orally in doses up to 450 mg daily (112940). A nonblinded clinical study in patients with refractory chronic lumbosacral radicular pain shows that taking alpha lipoic acid orally, 600 mg three times daily for 3 weeks followed by 600 mg daily for 2 weeks, in addition to a single, pulsed radiofrequency treatment to the dorsal ganglion, improves pain severity and disability scores at 6 months when compared with pulsed radiofrequency treatment alone. A pain score of less than 4 is achieved at 12 weeks in about 80% of patients taking alpha lipoic acid, compared with about 65% of patients without alpha-lipoic acid. (107895).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral alpha-lipoic acid is beneficial for NAFLD. Details: Small clinical studies in adults with NAFLD and obesity show that taking alpha-lipoic acid 600 mg orally twice daily for 8-12 weeks does not improve liver health markers, such as liver function test levels or liver steatosis, cholesterol levels, body weight, or visceral fat when compared with placebo or control (104660,100710,111304). However, these clinical trials show that taking alpha-lipoic acid 600 mg orally twice daily for 8-12 weeks may provide small improvements in interleukin-6 levels, adiponectin levels, and insulin resistance (104660,100710). However, these studies may have been inadequately powered to detect differences in some of these outcomes.
• Orthostatic hypotension. It is unclear if oral alpha-lipoic acid is beneficial for orthostatic hypotension. Details: Preliminary clinical research shows that taking alpha-lipoic acid 430-788 mg orally daily for a mean of 2.3 years attenuates changes in blood pressure upon standing when compared with baseline in some patients with chronic neurogenic orthostatic hypotension or orthostatic intolerance (101868).
• Osteoarthritis. It is unclear if oral alpha-lipoic acid is beneficial for osteoarthritis. Details: A small nonrandomized study in adults with osteoarthritis and type 2 diabetes shows that taking alpha lipoic acid 600 mg daily for 6 weeks with standard therapy (e.g., nonsteroidal anti-inflammatory medications) improves patient-reported assessment of pain and functionality when compared with standard therapy alone (115743). However, clinical significance is unclear, and the validity of these results is limited due to the lack of statistical adjustment for multiple comparisons.
• Pain (chronic). It is unclear if oral alpha-lipoic acid is beneficial for various chronic pain conditions. Details: A clinical study in patients with untreated, mild to moderate idiopathic pain (i.e. neuropathic pain, joint pain, and muscle pain with unknown etiology) shows that taking oral alpha-lipoic acid 400 mg once or twice daily for 2 months may improve pain severity when compared with baseline, with greater effects observed with daily doses of 800 mg (107887). Although the study enrolled a control group, a statistical comparison between groups was not conducted, limiting the validity of this finding. Additionally, sub-analyses evaluating outcomes based on type of chronic pain were not conducted.
• Periodontitis. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with moderate or advanced periodontitis shows that taking a supplement containing alpha-lipoic acid 25 mg, coenzyme Q10, cranberry extract, grapeseed extract, selenium, vitamin C, vitamin E, and zinc twice daily for 8 weeks in addition to standard nonsurgical therapy does not reduce periodontal indices including bleeding on probing, gingival recession, plaque index, or inflammation, among others, when compared with placebo (111708).
• Peripheral arterial disease (PAD). It is unclear if oral alpha-lipoic acid is beneficial for PAD. Details: Preliminary clinical research shows that taking alpha-lipoic acid 300 mg twice daily reduces pain associated with exercise in people with PAD and claudication when compared with placebo. However, exercise tolerance does not seem to improve (16391).
• Polycystic ovary syndrome (PCOS). It is unclear if oral alpha-lipoic acid is beneficial for PCOS. Details: Alpha-lipoic acid has been studied alone and in combination with inositol for the treatment of PCOS. A meta-analysis of 7 clinical trials in young adults with overweight and PCOS shows that taking alpha-lipoic acid 600-1800 mg daily for 6-25 weeks, alone or in combination with inositol, reduces fasting blood sugar and homeostatic model assessment of insulin resistance (HOMA-IR) when compared with control. However, there is no effect on insulin levels, body mass index, lipid profile, or hormone levels (112939). Alpha-lipoic acid has also been evaluated in a number of retrospective observational studies for PCOS. A small retrospective study in patients with PCOS and overweight or obesity suggests that taking alpha-lipoic acid 400 mg daily for 12 weeks is associated with improved insulin sensitivity, hepatic insulin extraction index, and levels of alanine transaminase and aspartate transaminase when compared to baseline. However, levels of reproductive hormones did not change over the 12 weeks (113895). Other observational research shows that taking alpha-lipoic acid 2000 mg, alone or in combination with myo-inositol (Sinopol, Laborest s.r.l.) 800-1000 mg, daily for 3-24 months is associated with reduced insulin levels and reduced menstrual cycle length, but not weight loss or improvements in hirsutism or insulin resistance, when compared to baseline (101869,101870). Another observational study shows that taking alpha lipoic acid 800 mg with a higher dose of myo-inositol 2000 mg is associated with slightly greater weight loss when compared with myo-inositol 1000 mg daily (103751). Also, taking alpha-lipoic acid 400 mg orally daily for 12 weeks does not affect levels of reproductive hormones, although improvements occur when alpha-lipoic acid is taken in combination with inositol 1000 mg daily (101870). The validity of this research is limited by the retrospective nature of the studies. Additionally, all of observational studies were conducted in Italy, which may limit generalizability of findings to other geographic regions and populations.
• Preterm labor. It is unclear if vaginal alpha-lipoic acid is beneficial for preventing preterm birth. Details: Preliminary clinical research shows that administering alpha-lipoic acid 400 mg vaginally once nightly for 30 days after an episode of preterm labor prevents cervical shortening when compared with placebo (96226). It is unclear if these findings are associated with a reduction in the rate of preterm birth.
• Radiation exposure. Oral alpha-lipoic acid might reduce radiation levels in children living in areas contaminated with radiation. Details: Preliminary clinical research shows that taking alpha-lipoic acid 400 mg, alone or in combination with vitamin E (RRR-alpha-tocopherol) 200 mg, daily for 28 days reduces chemiluminescence in leukocytes and urinary radioactivity when compared to baseline in children living in areas contaminated with radiation (21669).
• Schizophrenia. There is mixed evidence regarding the effectiveness of oral alpha-lipoic acid in patients with schizophrenia. Details: A small clinical study in patients with treatment-resistant schizophrenia receiving conventional antipsychotic therapy shows that taking alpha-lipoic acid 300 mg daily for 8 weeks improves scores related to negative symptoms of schizophrenia, but not positive symptoms, when compared with placebo (110114). A very small, open-label study in patients with stable, chronic schizophrenia shows that taking alpha-lipoic acid 100 mg daily along with ongoing antipsychotic medication for 4 months improves symptoms by 64% when compared to baseline. Specific symptom domains, including negative and positive symptoms, excitement, depressive symptoms, and extrapyramidal symptoms all show improvement, although the validity of these findings is limited by the lack of a control group (96228). In contrast, another small clinical study in patients with schizophrenia stabilized on antipsychotic therapy for at least 1 year shows that taking alpha-lipoic acid 100 mg daily for 16 weeks does not improve symptoms of schizophrenia or cognitive function when compared with placebo (110115). Also, a very small, open-label study in patients with schizophrenia shows that taking alpha-lipoic acid 600 mg daily along with conventional antipsychotic therapy for 12 weeks does not improve positive or negative symptoms of schizophrenia when compared to baseline (110116). A meta-analysis of 4 studies in patients with clinically stable schizophrenia does not show any benefit of oral alpha-lipoic acid when compared with placebo, although details of the analysis are limited (112936). Overall, the reasons for the disparate research findings are unclear, but they may be due to differences in the alpha-lipoic acid dose, treatment duration, and severity of schizophrenia across studies. Alpha-lipoic acid has also been evaluated in combination with other ingredients. A small clinical study in patients who responded well to antipsychotic therapy after a single episode of psychosis shows that taking alpha-lipoic acid 150 mg, eicosapentaenoic acid (EPA) 1000 mg, and docosahexaenoic acid (DHA) 500 mg twice daily does not prevent 2-year cumulative relapse or delay relapse time when compared with placebo (90675).
• Sciatica. It is unclear if oral alpha-lipoic acid is beneficial for sciatica. Details: Preliminary clinical research in patients with sciatica secondary to a herniated disc shows that taking alpha-lipoic acid (Byodiniral 300 QR, MDM SpA) 600 mg daily for 60 days improves signs and symptoms of sciatica and decreases the use of analgesics when compared with taking acetyl-L-carnitine (Nicetile, SigmaTau Ind. Farm. Riunite SpA) 1180 mg daily (21671). However, taking alpha-lipoic acid does not affect sleep quality in these patients. Alpha-lipoic acid has also been studied in combination with other ingredients for sciatica. Research in patients with sciatica secondary to a herniated disk shows that taking a combination of alpha-lipoic acid 600 mg with acetyl-L-carnitine, resveratrol, and cholecalciferol orally once daily for 30 days, concurrently with a physiotherapy protocol, reduces pain and disability, and improves quality of life when compared with the physiotherapy protocol alone (112933). Additionally, observational research in patients with sciatic pain due to herniated discs suggests that taking a combination of alpha-lipoic acid 800 mg, myrrh extract 200 mg, and palmitoylethanolamide 600 mg daily for 20 days along with 3 sessions of oxygen-ozone therapy over 30 days is associated with slight improvements in pain when compared with oxygen-ozone therapy alone (111113). It is unclear if the effects are due to alpha-lipoic acid, other ingredients, or the combination.
• Tinnitus. It is unclear if oral alpha-lipoic acid is beneficial for tinnitus. Details: A small observational study in patients with tinnitus associated with cochlear dysfunction and metabolic syndrome suggests that taking alpha-lipoic acid 600 mg for 60 days is associated with improvements in several audiometric parameters and overall tinnitus handicap inventory scores, with a larger effect on functional and emotional scores, when compared to baseline. However, patients with tinnitus secondary to acoustic nerve lesions do not appear to benefit from alpha-lipoic acid supplementation (111705). The validity of these effects is limited by a lack of a comparator group.
• Toxin-induced liver damage. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients being treated with anti-tuberculosis drugs shows that taking alpha-lipoic acid 250 mg, coenzyme Q10 200 mg, and acetyl-L-carnitine 250 mg twice daily for 2 weeks reduces the risk of drug-induced liver injury by 73% when compared with placebo (107445). It is unclear if these findings are due to alpha-lipoic acid, other ingredients, or the combination.
• Vertigo. Oral alpha-lipoic acid has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with benign paroxysmal positional vertigo with serum 25-hydroxyvitamin D levels less than 20 ng/mL shows that taking a specific combination product containing alpha-lipoic acid 600 mg, zinc 7.5 mg, L-carnosine 165 mg, curcumin 100 mg, piperine 1 mg, cholecalciferol 800 units, vitamin B2 0.8 mg, and vitamin B6 1 mg (Vertistop D, Difass) orally daily for 6 months moderately reduces the number of vertigo relapse episodes when compared with control. However, in patients with serum 25-hydroxyvitamin D levels greater than 20 ng/mL that took a specific combination product containing alpha-lipoic acid 600 mg, zinc 7.5 mg, L-carnosine 165 mg, curcumin 100 mg and piperine 1 mg (Vertistop L, Difass) orally daily for 6 months there was no difference in relapse episodes when compared with control (111294). It is unclear if this effect is due to alpha-lipoic acid, other ingredients, or the combination.
• Vitiligo. It is unclear if oral alpha-lipoic acid is beneficial for vitiligo when used in conjunction with phototherapy. Details: When used in combination with phototherapy, clinical research shows that taking alpha-lipoic acid (Shandong Qidu Pharmaceutical Co., Ltd.) 300 mg daily for 6 months does not improve repigmentation when compared with placebo (104654). In contrast, a small clinical study shows that taking two tablets of a specific combination product (Lipoacid Combi, General Topics) containing alpha-lipoic acid 50 mg, vitamin C 50 mg, vitamin E 20 mg, and polyunsaturated fatty acids 12%, starting 8 weeks prior to ultraviolet B phototherapy and continuing for 6 months during phototherapy treatment, seems to increase the likelihood of repigmentation by 29% when compared with placebo (19210). It is not clear if this effect is due to alpha-lipoic acid, other ingredients, or the combination.
• Wilson disease. Although there is interest in using oral alpha-lipoic acid for Wilson disease, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for this condition.
• Wound healing. It is unclear if oral alpha-lipoic acid is beneficial for wound healing. Details: A small clinical study shows that taking a specific alpha-lipoic acid product (Byodinoral 300, M.D.M. Spa) 300 mg one hour before and one hour after hyperbaric oxygen therapy administered daily for 14-30 days reduces wound area in 30% more patients with ischemic ulcers when compared with hyperbaric oxygen therapy alone (21677).
• Wrinkled skin. Although there is interest in using topical alpha-lipoic acid for wrinkled skin, there is insufficient reliable information about the clinical effects of alpha-lipoic acid for this condition. More evidence is needed to rate alpha-lipoic acid for these uses.

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POSSIBLY EFFECTIVE

• Alzheimer disease. Oral huperzine A seems to improve memory, cognitive function, and behavior in patients with this condition. Details: Meta-analyses of small clinical studies in patients with Alzheimer disease show that, overall, huperzine A 200-800 mcg in 2-3 divided doses daily for 8-36 weeks improves cognitive function as measured on some scales, but not others, when compared with placebo (55674,93482). Improvement in cognitive function was observed consistently when measured using the Mini-Mental State Examination (MMSE) (55674,93482,93483,101469). However, results are inconsistent with other scales, such as the Alzheimer Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), the Hasegawa Dementia Scale (HDS), and the Wechsler Memory Scale (WMS) (55674,93482). Meta-analyses also show that huperzine A improves overall behavior and performance of daily living activities when compared with placebo (55674,93482). Most research has been conducted in China, where huperzine A is an approved drug for this condition. Only one clinical trial has been conducted in the United States. This study was conducted in patients with probable mild to moderate Alzheimer disease and shows that taking huperzine A 200 mcg twice daily for at least 16 weeks does not improve cognition based on the ADAS-Cog when compared with placebo. However, this dose results in modest benefit when cognition is measured using the MMSE, and a higher dose of 400 mcg twice daily shows modest benefit when measured on both the ADAS-Cog and MMSE (93479). Long-term, large-scale clinical trials in diverse geographic locations are necessary to confirm these findings and determine which dose of huperzine A, if any, is beneficial.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Athletic performance. It is unclear if oral huperzine A is beneficial for improving athletic performance. Details: One very small, double-blind randomized crossover study in physically active adults shows that taking huperzine A 200 mcg as a single dose 30-45 minutes prior to exercise does not affect athletic performance, neuromuscular performance, or cognitive function when compared with placebo (107470). Due to the single-dose nature of this study, the effects of continued administration of huperzine A on athletic performance are unclear.
• Cocaine dependence. It is unclear if oral huperzine A is beneficial in patients with cocaine use disorder. Details: A very small clinical study in adults with cocaine use disorder shows that taking huperzine A in gradually increasing doses over 9 days, up to a dose of 200 or 400 mcg twice daily, might attenuate the stimulation and anxiety effects of an intravenous cocaine infusion when compared with placebo (93484). It is unclear if huperzine A can attenuate cravings and cocaine use in these individuals.
• Cognitive impairment. Although there is interest in using oral huperzine A for mild cognitive impairment, there is insufficient reliable information about the clinical effects of huperzine A for this condition.
• Depression. It is unclear if oral huperzine A is beneficial in patients with major depressive disorder. Details: A meta-analysis of three small, low-quality clinical studies in patients with major depressive disorder shows that taking huperzine A 100-300 mg daily in combination with antidepressants for 6-8 weeks does not further improve depressive symptoms when compared with antidepressants alone. However, huperzine A might improve cognitive functioning, based on the Wisconsin Card Sorting Test and the Wechsler Memory Scale-Revised (WMS-R) (93485). All available research has been conducted in China, so it is unclear if these findings are generalizable to other geographic locations.
• Memory. It is unclear if oral huperzine A is beneficial for improving memory in healthy adolescents. Details: A small clinical trial in Chinese adolescents around 15 years of age who complain of poor memory shows that taking huperzine A 100 mcg daily for 4 weeks improves memory quotient scores when compared with placebo (4626).
• Myasthenia gravis. It is unclear if intramuscular huperzine A is beneficial in patients with myasthenia gravis. Details: A small, open-label clinical trial in stabilized patients with myasthenia gravis shows that giving huperzine A 400 mcg intramuscularly for 10 days maintains muscle strength similarly to patients treated with intramuscular neostigmine alternating with intramuscular huperzine A. Huperzine A was reported to have a 7-hour duration of effect, compared to only 4 hours with neostigmine (3561).
• Schizophrenia. Small clinical studies suggest that oral huperzine A may modestly improve symptoms of schizophrenia in adults. Details: A meta-analysis of small, low-quality clinical trials in hospitalized patients with schizophrenia shows that taking huperzine A 150-400 mcg daily for 8-24 weeks as an adjunct to antipsychotic medications improves memory, intelligence, and positive, but not negative, psychiatric symptoms when compared with antipsychotic medications alone (93478). Limited research also suggests that huperzine A might improve outcomes in patients with resistant schizophrenia and cognitive impairment. A small, open-label clinical study in patients with treatment-resistant schizophrenia and cognitive impairment shows that adding huperzine A 300 mcg daily for 12 weeks to treatment with antipsychotics improves negative symptoms of schizophrenia by 32% and memory by 15% when compared to baseline (55665). The validity of this finding is limited by the lack of a comparator group. Furthermore, all available research has been conducted in China, so it is unclear if these findings are generalizable to other geographic locations.
• Vascular dementia. Small clinical studies suggest that oral huperzine A may modestly improve symptoms of vascular dementia in adults. Details: A meta-analysis of two small clinical trials in patients with vascular dementia shows that taking huperzine A 200-300 mcg daily for 12-24 weeks modestly improves cognitive function and activities of daily living when compared with control (93483). The validity of this meta-analysis is limited by small study size and publication bias. More evidence is needed to rate huperzine A for these uses.

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POSSIBLY EFFECTIVE

• Dementia. Oral vinpocetine, taken for up to 1 year, might improve cognitive function to a small degree in patients with dementia. Details: While some conflicting evidence exists (1784), several small clinical studies in patients with cognitive impairment due to various causes including dementia, Alzheimer disease, and vascular disease show that taking vinpocetine 5-20 mg three times daily for up to 1 year slightly to modestly improves cognitive function when compared with baseline scores or placebo (1787,1789,82151,82152,82153,82154,82179,82180)(82182,82183,92934,111333). However, most of these studies were published prior to 1990 and used diagnostic and evaluative criteria that limit the applicability of these results to current clinical practice (10221,10827,111333).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Age-related cognitive decline. Although there has been interest in using oral vinpocetine for age-related cognitive decline, there is insufficient reliable information about the clinical effects of vinpocetine for this purpose.
• Age-related macular degeneration (AMD). It is unclear if oral vinpocetine is beneficial in patients with AMD. Details: One small clinical study in patients with AMD shows that taking vinpocetine 10 mg daily for 2 months, in conjunction with conventional therapy, improves visual acuity and retinal function when compared with conventional therapy alone (82089).
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral vinpocetine for CFS, there is insufficient reliable information about the clinical effects of vinpocetine for this purpose.
• Epilepsy. Although there has been interest in using oral and intravenous vinpocetine for epilepsy, there is insufficient reliable information about the clinical effects of vinpocetine for this purpose.
• Hearing loss. It is unclear if oral or intravenous vinpocetine is beneficial in patients with hearing loss. Details: One small clinical study in patients with acoustic trauma shows that intravenous administration of vinpocetine 10 mg twice daily for 10 days is less effective than nicergoline, an ergot derivative, for improving hearing loss (82147). Another small, open-label clinical study in patients with sensorineural hearing loss shows that taking vinpocetine 10 mg three times daily for 12 months improves some measures of hearing capacity, particularly in months 6-12, when compared to baseline (106845). The validity of these findings is limited by a lack of control group.
• Memory. Small clinical studies suggest that oral vinpocetine might slightly improve memory in healthy individuals. Details: Two very small clinical studies in healthy individuals show that taking vinpocetine 40 mg as a single dose or vinpocetine 10-40 mg three times daily for 2 days enhances some measures of memory when compared with placebo (1796,1797). Additionally, one small clinical study in healthy adults shows that taking a combination product containing vinpocetine 10 mg, ginkgo extract 40 mg, and other ingredients three times daily for 2 weeks improves short-term memory when compared with placebo (8544). It is unclear if these findings are due to vinpocetine, other ingredients, or the combination.
• Menopausal symptoms. Although there has been interest in using oral vinpocetine for menopausal symptoms, there is insufficient reliable information about the clinical effects of vinpocetine for this purpose.
• Motion sickness. Although there has been interest in using oral vinpocetine for motion sickness, there is insufficient reliable information about the clinical effects of vinpocetine for this purpose.
• Stroke. Research on the use of intravenous vinpocetine to improve outcomes in patients recovering from ischemic stroke is mixed. It is unclear if oral vinpocetine is beneficial in these patients. Details: Some small clinical studies show that vinpocetine modestly reduces the residual effects of acute ischemic stroke (1785,10222,82087,82091,82120,82158,82159,82186). However, most clinical studies investigating the use of vinpocetine for stroke have been published in languages other than English and assessed intravenous formulations of vinpocetine not available in the US. One large clinical study shows that intravenous administration of vinpocetine 30 mg once daily for 7 days after an acute stroke, in addition to oral citicoline and aspirin or clopidogrel, seems to improve cerebral blood flow and measures of cognition, neurological function, and quality of life when compared with citicoline plus aspirin or clopidogrel (98226). A meta-analysis of 4 moderate-to-good quality clinical studies that included 837 adults with acute ischemic stroke, some of which are described above, shows that intravenous administration of vinpocetine in addition to standard care, followed by oral administration in some studies, reduces significant disability when compared with standard care. Vinpocetine also seems to improve cognition scores but does not reduce mortality (110744). The included studies used widely heterogeneous dosing regimens and excluded patients with severe strokes. However, a small clinical study not included in the meta-analysis shows that intravenous vinpocetine 20 mg followed by oral vinpocetine 10 mg three times daily for 3 months does not significantly improve neurophysical functioning post-stroke when compared with placebo (82074).
• Tinnitus. It is unclear if oral or intravenous vinpocetine is beneficial in patients with tinnitus. Details: A small observational study in patients with chronic unilateral or bilateral tinnitus has found that intravenous infusion of a specific vinpocetine product (Cavinton) 20 mg plus oral vinpocetine (Cavinton) 10 mg twice daily along with physiotherapy is associated with improved symptoms when compared to baseline (82099). However, a small clinical study in patients with tinnitus due to acoustic trauma shows that intravenous administration of vinpocetine (Cavinton) 10 mg twice daily appears to be less effective than nicergoline, an ergot derivative, for reducing tinnitus (82147).
• Urinary incontinence. It is unclear if oral vinpocetine is beneficial in patients with urinary incontinence. Details: One small, uncontrolled clinical study in patients with urinary incontinence shows that taking vinpocetine 10 mg three times daily for 2 weeks reduces daytime and nighttime frequency of urination when compared to baseline (82041). The validity of these findings is limited by a lack of control group. More evidence is needed to rate vinpocetine for these uses.

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LIKELY SAFE ...when used orally and appropriately. Acetyl-L-carnitine has been used safely in doses up to 3 grams daily in clinical trials lasting up to 33 months (42,1589,1594,1595,1596,1597,1598,1599,3600,3601) (9105,9791,10076,12743,12745,58375,90755,90756,90759,90761)(90766,90767,90768,95063,95067,111862).

POSSIBLY SAFE ...when used parenterally and appropriately under medical supervision (1591,1592,12743).

CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term. Acetyl-L-carnitine has been safely used orally in children for up to 6 weeks (90754).

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

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POSSIBLY SAFE ...when used orally and appropriately. Alpha-lipoic acid has been used with apparent safety in doses of up to 2 grams daily for 3 months to 2 years. Lower doses of 600 mg daily have been used with apparent safety for up to 4 years (3540,3541,3542,20479,96449,97630,101867,101869,103327,103333)(103335,104651,104660,113892,113897). ...when used topically and appropriately. A cream containing alpha-lipoic acid 5% has been used with apparent safety in clinical trials lasting up to 12 weeks (12021). ...when given intravenously and appropriately. Intravenous alpha-lipoic acid has been used safely in doses of up to 6000 mg weekly in clinical trials lasting up to 3 weeks (3540,3557,10148,12106).

CHILDREN: POSSIBLY SAFE
when used orally and appropriately. Alpha-lipoic acid has been used with apparent safety in doses of up to 600 mg daily for 3 months in children aged 10-17 years (103330).

CHILDREN: POSSIBLY UNSAFE
when used orally in amounts over 600 mg daily. At least five cases of alpha-lipoic acid intoxication have been reported for children aged 14 months to 16 years who consumed alpha-lipoic acid at doses up to 226 mg/kg (approximately 2400 mg). Symptoms of alpha-lipoic acid-induced intoxication included seizures, acidosis, vomiting, and unconsciousness (90444,96227,96234,104653).

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately, short-term. Alpha-lipoic acid has been used safely during pregnancy at doses up to 600 mg daily for up to 4 weeks (96222).

LACTATION:
Insufficient reliable information available; avoid using.

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POSSIBLY SAFE ...when used orally and appropriately, short-term. Huperzine A 200-800 mcg daily has been used with apparent safety in clinical trials lasting up to 6 months (3171,3561,4626,93478,93479,93480,93481,93482,93483,93485).

CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term. Huperzine A has been used with apparent safety in clinical research lasting for 1 month (4626).

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

(Read more about HUPERZINE A)

POSSIBLY SAFE ...when used orally and appropriately for up to 12 months (1784,1788,82041,82074,82089,82091,82120,82121,82151,82152)(82153,82154,82179,82180,82182,82183,104522,106845,110744). ...when used intravenously and appropriately, short-term (82074,82099,82147,82158,82159,82186,110744).

PREGNANCY: POSSIBLY UNSAFE
when used orally. In June 2019, the US Food and Drug Administration (FDA) issued a statement of warning that those who are pregnant or who could become pregnant should avoid vinpocetine (95751). In rats, vinpocetine has been associated with an increased risk of miscarriage at a dose of 60 mg/kg daily and with reduced fetal weight and increased incidence of birth defects at a dose of 5-20 mg/kg. Based on pharmacokinetic analyses, a daily vinpocetine dose of 10 mg in humans is comparable to a daily dose of 5 mg/kg in rats (99701).

LACTATION:
Insufficient reliable information available; avoid using.

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ACENOCOUMAROL (Sintrom) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, acetyl-L-carnitine might increase the anticoagulant effects of acenocoumarol.  Details L-carnitine, the parent compound of acetyl-L-carnitine, might enhance the anticoagulant effects of acenocoumarol, an oral anticoagulant that is similar to warfarin, but shorter-acting (9878,12165). There are at least two case reports of INR elevation when L-carnitine was taken with acenocoumarol. 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). It is unclear if such an interaction would also occur with acetyl-L-carnitine.

SEROTONERGIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, acetyl-L-carnitine might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders, when taken with serotonergic drugs.  Details Animal research shows that acetyl-L-carnitine can increase levels of serotonin in the brain (95065).

THYROID HORMONE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, acetyl-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). It is unclear if such an interaction would occur with acetyl-L-carnitine.

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, acetyl-L-carnitine might increase the anticoagulant effects of warfarin.  Details L-carnitine, the parent compound of acetyl-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 acetyl-L-carnitine and warfarin.

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ALKYLATING AGENTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the antioxidant effects of alpha-lipoic acid might alter the effectiveness of alkylating agents.  Details The use of antioxidants like alpha-lipoic acid during chemotherapy is controversial. There are concerns that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals (391). However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells (14012,14013). More evidence is needed to determine what effect, if any, antioxidants such as alpha-lipoic acid have on chemotherapy. Advise patients to consult their oncologist before using alpha-lipoic acid.

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, alpha-lipoic acid may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.  Details In vitro, alpha-lipoic acid inhibits platelet aggregation (98682).

ANTIDIABETES DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, taking alpha-lipoic acid with antidiabetes drugs might increase the risk of hypoglycemia.  Details Although some small clinical studies have suggested that alpha-lipoic acid can lower blood glucose levels (3545,3874,3875,3876,20490,20493,104650), larger clinical studies in patients with diabetes have shown no clinically meaningful effect (20494,20495,20496,90443,90445,110118). Additionally, co-administration of single doses of alpha-lipoic acid and glyburide or acarbose did not cause detectable drug interactions in healthy volunteers (3870).

ANTITUMOR ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the antioxidant effects of alpha-lipoic acid might alter the effectiveness of antitumor antibiotics.  Details The use of antioxidants like alpha-lipoic acid during chemotherapy is controversial. There are concerns that antioxidants could reduce the activity of antitumor antibiotic drugs, which work by generating free radicals (391). However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells (14012,14013). More evidence is needed to determine what effect, if any, antioxidants such as alpha-lipoic acid have on chemotherapy involving antitumor antibiotics. Advise patients to consult their oncologist before using alpha-lipoic acid.

THYROID HORMONE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, alpha-lipoic acid might decrease the effects of thyroid hormone drugs.  Details Animal research suggests that co-administration of thyroxine with alpha-lipoic acid reduces conversion into the active T3 form (8946).

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ANTICHOLINERGIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, huperzine A might decrease the effects of anticholinergic drugs.  Details Huperzine A has acetylcholinesterase (AChE) inhibiting effects. In animal models, huperzine A reversed cognitive deficits induced by scopolamine, an anticholinergic drug (3134,3135,55692).

CHOLINERGIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concurrent use of huperzine A with cholinergic drugs might increase the effects and side effects of these medications.  Details Huperzine A can inhibit acetylcholinesterase (AChE) and might cause cumulative effects if used with cholinergic drugs (3131).

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ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Vinpocetine might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.  Details Clinical research shows that vinpocetine decreases red blood cell aggregation, as well as plasma and whole blood viscosity. This effect has been seen with intravenous vinpocetine 1 mg/kg and oral vinpocetine 30 mg daily (82101,82119). Vinpocetine also seems to have antiplatelet effects (1801,10061,82117).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, vinpocetine might increase levels of drugs metabolized by CYP2C9.  Details In vitro research shows that vinpocetine weakly inhibits CYP2C9 (92933). However, this effect has not been reported in humans.

WARFARIN (Coumadin) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Vinpocetine might modestly increase the risk of bleeding when taken with warfarin.  Details Clinical research shows that the combination of warfarin and vinpocetine leads to slight increases in prothrombin time and the area under the concentration curve for warfarin. However, these increases were small, and researchers suggest that this interaction is not likely to be clinically significant in most patients (10829).

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General ...Orally, acetyl-L-carnitine is generally well tolerated.
Most Common Adverse Effects:
Orally: Agitation, dry mouth, headache, insomnia, and reduced appetite. A metabolite of acetyl-L-carnitine has been reported to cause a fishy odor of the urine, breath, and sweat.

Cardiovascular ...Orally, one patient in a pharmacokinetic study reported high blood pressure 8 hoursafter taking acetyl-L-carnitine 500 mg; however, it is unclear if this was due to acetyl-L-carnitine or another factor (95061).

Dermatologic ...Orally, a combination of acetyl-L-carnitine and alpha-lipoic acid may cause rash (90441).

Gastrointestinal ...Orally, acetyl-L-carnitine may cause nausea, vomiting, diarrhea, constipation, hiccups, abdominal distension and gastrointestinal upset or pain. However, gastrointestinal symptoms do not usually occur more often in patients receiving acetyl-L-carnitine than in patients receiving placebo (1596,1599,12743,13007,58922,90755,95063,95067,111889,111894). Acetyl-L-carnitine may also cause dry mouth and anorexia (58342). When taken orally, a combination of acetyl-L-carnitine and alpha-lipoic acid may cause diarrhea, constipation, and dyspepsia (90441).

Neurologic/CNS ...Orally, acetyl-L-carnitine may cause headache and insomnia (90760,90767,95063). In one clinical trial, two patients with antiretroviral toxic neuropathy reported paresthesia, pain, and neuropathy after taking acetyl-L-carnitine 1000 mg daily (58342). A case of mania has been reported for a patient with bipolar I disorder currently in remission. The patient presented with symptoms after taking multiple supplements for the past 4 weeks including acetyl-L-carnitine 1000 mg twice daily. The symptoms appeared 3 days after beginning to take acetyl-L-carnitine and worsened over the next week. The patient had increased speech rate and volume and reported increased energy levels and racing thoughts. The patient's parent reported irritability and an increase in loud behaviors at home, similar to a previous episode of mania. The patient was advised to discontinue acetyl-L-carnitine, and the manic symptoms disappeared 3 days later (95062).

Psychiatric ...Orally, acetyl-L-carnitine may cause agitation (restlessness and motor overactivity) (1596,1599,12743,13007). Side effects reported in people with Alzheimer disease include psychiatric disturbances such as depression, mania, confusion and aggression, but it is not clear whether these are due to acetyl-L-carnitine or the condition itself (1594,1595,1596,1597,1598,1599,9105,10391).

Other ...One of the metabolites of acetyl-L-carnitine can cause the urine, breath, and sweat to have a fishy odor (12756). Also, foul smelling urine has been reported following oral use of a combination of acetyl-L-carnitine and alpha-lipoic acid (90441).

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General ...Alpha-lipoic acid appears to be generally well tolerated when used orally, intravenously, or topically.
Most Common Adverse Effects:
Orally: Headache, heartburn, nausea, and vomiting.
Topically: Irritation and rash.
Intravenously: Nausea and vomiting.
Serious Adverse Effects (Rare):
Orally: Case reports have raised concerns about insulin autoimmune syndrome (IAS).

Cardiovascular ...Orally, hypotension has been reported rarely in a clinical trial (104650).

Dermatologic ...Orally, skin rash and itching have been reported after use of alpha-lipoic acid (16391,20490,21674,96233,104650). Topically, alpha-lipoic acid can cause local irritation, including burning, stinging, mild rash, or contact dermatitis (12021,30836,111701). In one case, an 86-year-old female developed allergic contact dermatitis with severe itching and oozing after applying alpha-lipoic acid 5% cream to her lower extremities. The patient had a positive skin patch test for alpha-lipoic acid, confirming the causative agent (111701). In another case, a 47-year-old female developed contact dermatitis characterized by a pruritic rash and labial adhesions hours after applying a 5% vulvar serum containing lipoic acid 0.9 grams, vitamin E, vitamin C, hyaluronic acid, and retinol palmitate to the vulva to treat vulvar lichen sclerosis. Testing confirmed that the causative agent was alpha-lipoic acid (111704). Intravenously, local allergic reactions have occurred at the injection site (1547).

Endocrine ...Orally, at least 50 published cases of insulin autoimmune syndrome (IAS) thought to be associated with use of alpha-lipoic acid have been reported (16392,104656,104657,104658,104659,107893,112941). Most reported cases have been associated with alpha-lipoic acid supplements or enriched foods; IAS has not been reported with intake of alpha-lipoic acid in food. IAS has been linked to compounds, such as alpha-lipoic acid, that contain sulfhydryl groups, but it is unclear if taking alpha-lipoic acid with other drugs known to trigger IAS increases the risk (107893,112941). IAS is characterized by very high serum insulin levels and high titers of autoantibodies against endogenous insulin. Sulfhydryl groups interact with disulfide bonds of insulin, increasing its immunogenicity (112941). Symptoms include severe spontaneous hypoglycemic episodes, as well as hunger and neuroglycopenic symptoms such as blurred vision, weakness, confusion, dizziness, sweating, and palpitations (104656,104657,107893,112941). Time to onset of IAS ranges from 1 week to 4 months (107893). Most cases of IAS have been reported in Japan and have occurred in individuals with the human leucocyte antigen (HLA)-DRB1*04:06 allele (16392,104656,107893). For patients of European decent, cases of IAS have mainly occurred in individuals with the HLA-DRB1*04:03 allele (104656,104658,104659,107893). This suggests that either of these alleles might produce a genetic predisposition to alpha-lipoic acid-associated IAS. Reported doses of alpha-lipoic acid have ranged from 200-800 mg daily, most commonly 600 mg daily (104656,104658,104659,107893). IAS-related hypoglycemic episodes have been treated with oral or intravenous glucose or sucrose, as well as prednisone. Episodes decline following discontinuation of alpha-lipoic acid, and insulin values normalize within 3-9 months (104656,104658,104659,107893).

Gastrointestinal ...Orally, heartburn, nausea, and vomiting have been reported after use of alpha-lipoic acid (3557,12106,16391,20475,30844,96225,101868,103327,103328,103333)(103335,104650,104654,104655). Higher doses (1200-1800 mg daily) seem to cause more severe effects than lower doses (600 mg daily) (3557,20475,30844,96225). Alpha-lipoic acid may also cause a burning sensation from the throat to the stomach, abdominal discomfort, or bitter taste when used orally (20478,20490,21664,96225). Intravenously, alpha-lipoic acid can cause gastrointestinal upset, including nausea and vomiting. Adverse effects are more common in patients receiving higher intravenous doses (3557) and may be more common in the elderly (96225).

Genitourinary ...Orally, alpha-lipoic acid may cause urinary disorders (20479). Oral alpha-lipoic acid has also been associated with a change in urine odor (96225,103327).

Neurologic/CNS ...Orally, alpha-lipoic acid may cause headache (21664,103328,104655) or dizziness (104650).
Intravenously, paresthesias have been reported to worsen temporarily at the beginning of therapy. Also, intravenous alpha-lipoic acid can cause headache. Adverse effects are more common in patients receiving higher intravenous doses (3557).

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General ...Orally, huperzine A seems to be well tolerated. There is currently a limited amount of information about the tolerability of intramuscular huperzine A.
Most Common Adverse Effects:
All ROAs: Huperzine A can cause dose-dependent cholinergic side effects such as blurred vision, constipation, diarrhea, dizziness, dry mouth, insomnia, nausea, sweating, and vomiting.

Cardiovascular ...Orally, huperzine A might cause decreased heart rate (3138,93482). There are two cases reported where consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including hypertension (13193).

Gastrointestinal ...Orally, huperzine A can cause cholinergic side effects such as nausea, vomiting, diarrhea, and anorexia (93480,93481,93482,93483). Constipation and thirst have also been reported (93482,93483). In two case reports, consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including vomiting and diarrhea (13193).

Musculoskeletal ...In two case reports, consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including leg cramps (13193).

Neurologic/CNS ...Orally, huperzine A can cause cholinergic side effects such as dizziness (3140,55613,93481,93482) and sweating (93482). Huperzine A can also cause hyperactivity and insomnia (3138,3140,55613,93482). Fainting has also been reported (4624). In two case reports, consumption of a tea mistakenly brewed from Lycopodium selago, a source of huperzine A, has resulted in significant cholinergic toxicity, including sweating and slurred speech (13193).

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General ...Orally and intravenously, vinpocetine seems to be well tolerated.
Most Common Adverse Effects:
Orally: Anxiety, dizziness, headache, flushing, gastric discomfort, sleep disturbances, and urticaria.
Serious Adverse Effects (Rare):
Orally: Agranulocytosis, arrhythmias, and seizures.
Intravenously: Arrhythmias.

Cardiovascular ...Orally, tachycardia, multifocal extra systoles, transient hypotension and hypertension, and palpitations have been reported with vinpocetine in clinical trials (1789,82118,82152,92936). One case of severe hypotension has been reported with oral vinpocetine (106845). Vinpocetine has also been reported to cause atrial fibrillation and ventricular arrhythmias, with the highest incidence occurring after intravenous or intramuscular administration (1789,82128,68753,82123).

Dermatologic ...Orally, vinpocetine has been reported to cause flushing, skin rash, and urticaria (82118,82120,82153,106845). Intravenously, vinpocetine has been associated with one report of allergic dermatitis (98226).

Gastrointestinal ...Orally, gastric discomfort, upper abdominal pain, nausea, diarrhea, constipation, vomiting, heartburn, difficulty swallowing, and dry mouth have been reported with vinpocetine (1787,1789,10061,10221,82120,82154,82155,92936,106845). Intravenously, diarrhea has been reported with vinpocetine (98226).

Hematologic ...Orally, vinpocetine has been associated with one case report of agranulocytosis (82156) and one case report of ecchymoma of the eyelid in a 60-year-old male 12 hours after a botulinum toxin injection. The patient had been taking vinpocetine 30 mg daily and aspirin 100 mg daily (112878).

Neurologic/CNS ...Orally, anxiety, drowsiness, headache, sleep disturbance, nervousness, excitation, hyperirritability, epileptiform convulsion, and vertigo have been reported with vinpocetine (1787,10221,68772,82118,82120,82151,82152,82154,92936,106845). Intravenously, dizziness has been reported with vinpocetine (98226).

Ocular/Otic ...Orally, vinpocetine has been associated with one case of eyelid edema (106845). Also, one case reports ecchymoma of the eyelid in a 60-year-old male 12 hours after a botulinum toxin injection. The patient had been taking vinpocetine 30 mg daily and aspirin 100 mg daily (112878).

Pulmonary/Respiratory ...Orally, vinpocetine has been associated with one case of severe dyspnea (106845).

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