Carnitine

80 research sources Also known as: l-carnitine carnitine acetyl-l-carnitine lcarnitine
882 Products on Market
500.0 mg Median Dose
🟢 100/100 Market Safety Score
80 Research Sources
Browse 882 products →

Top-Rated Carnitine Products

View all Carnitine products → Best Carnitine rankings →

Evidence Summary

Carnitine is a nutrient involved in energy metabolism and fatty acid transport. Research suggests potential benefits for specific clinical conditions such as peripheral arterial disease, diabetic neuropathy, and male infertility, though evidence for cognitive enhancement in healthy individuals is less certain.

Evidence by Condition

Propionyl-L-carnitine may assist in managing symptoms of peripheral arterial disease (PMID: 34954832).

Carnitine supplementation may be beneficial for patients requiring dialysis (PMID: 36472884).

Acetyl-L-carnitine is studied for its efficacy in treating this complication (PMID: 31201734).

Male Infertility Moderate

Carnitine and CoQ10 may improve sperm quality and pregnancy rates in men with unexplained infertility (PMID: 40813743).

Acetyl-L-carnitine is investigated for managing this neuropsychiatric complication (PMID: 30610762).

Carnitine deficiency is considered a potential pathway for treating fatigue in cancer patients (PMID: 29112178).

Systematic reviews have examined carnitine's role in managing fatigue in MS patients (PMID: 22592719).

Effective Doses

No specific dose ranges were provided in the source text.

Key Findings

  • Acetyl-L-carnitine shows potential for the treatment of diabetic peripheral neuropathy (PMID: 31201734).
  • Carnitine and CoQ10 may improve sperm quality and pregnancy rates in men with unexplained infertility (PMID: 40813743).
  • L-carnitine may improve cardiac function in patients undergoing hemodialysis (PMID: 40172612).

Limitations

Much of the high-quality research is focused on specific clinical populations, such as patients with CKD or PAD, rather than healthy individuals.

Safety & Interactions

The provided research does not explicitly list specific contraindications or drug interactions.

AI-generated summary from 80 peer-reviewed studies. Not medical advice. Always consult a healthcare provider.

Dietary Reference Intakes

Source: IOM/NAM Dietary Reference Intakes · Dietary Reference Intakes: L-Carnitine

Claims vs. Evidence

100% Evidence-Backed
0% Unsupported
88% Structure/Function
Claim Type% of ProductsEvidence RequiredStatus
All Other 99% Tier D (Unclassified) ✅ Supported
Structure/Function 88% Tier C (DSHEA Structure/Function (no pre-approval)) ✅ Supported
Nutrient 18% Tier D (Unknown) ✅ Supported
No Claim 0% Tier D (No claim on label) ✅ Supported
Qualified Health 0% Tier B (FDA Qualified Health Claim) ✅ Supported
Approved Health 0% Tier A (FDA Approved Health Claim (21 CFR 101.9)) ✅ Supported

🏛️ NIH ODS Factsheet

Research by Topic

Research Evidence (80)

Rct: 43 Clinical Trial: 14 Systematic Review: 11 Meta Analysis: 9 Regulatory Source: 2
A Propionyl-L-carnitine for intermittent claudication
Meta Analysis The Cochrane database of systematic reviews 2021 n=1395

BACKGROUND: Peripheral arterial disease (PAD) is a manifestation of systemic atherosclerosis. Intermittent claudication is a symptomatic form of PAD that is characterized by pain in the lower limbs caused by chronic occlusive arterial disease. This p...

A Carnitine supplements for people with chronic kidney disease requiring dialysis
Systematic Review The Cochrane database of systematic reviews 2022 n=134

BACKGROUND: Carnitine deficiency is common in patients with chronic kidney disease (CKD) who require dialysis. Several clinical studies have suggested that carnitine supplementation is beneficial for dialysis-related symptoms. However, the clinical e...

A Acetyl-L-carnitine for patients with hepatic encephalopathy
Meta Analysis The Cochrane database of systematic reviews 2019 n=398

BACKGROUND: Hepatic encephalopathy is a common and devastating neuropsychiatric complication of acute liver failure or chronic liver disease. Ammonia content in the blood seems to play a role in the development of hepatic encephalopathy. Treatment fo...

A Acetyl-L-carnitine for the treatment of diabetic peripheral neuropathy
Meta Analysis The Cochrane database of systematic reviews 2019 n=907

BACKGROUND: Diabetic peripheral neuropathy (DPN) is a common and severe complication that affects 50% of people with diabetes. Painful DPN is reported to occur in 16% to 24% of people with diabetes. A complete and comprehensive management strategy fo...

B Carnitine for fatigue in multiple sclerosis
Systematic Review The Cochrane database of systematic reviews 2012

BACKGROUND: Fatigue is reported to occur in up to 92% of patients with multiple sclerosis (MS) and has been described as the most debilitating of all MS symptoms by 28% to 40% of MS patients. OBJECTIVES: To assess whether carnitine (enteral or intrav...

B L-carnitine for cognitive enhancement in people without cognitive impairment
Meta Analysis The Cochrane database of systematic reviews 2017 n=18

BACKGROUND: Safe interventions to enhance cognitive function in cognitively healthy people would be very valuable for several reasons, including a better quality of life and professional success. While L-carnitine has been reported to enhance cogniti...

B Carnitine for fatigue in multiple sclerosis
Systematic Review The Cochrane database of systematic reviews 2010

BACKGROUND: Fatigue is reported to occur in up to 92% of patients with multiple sclerosis (MS) and has been described as the most debilitating of all MS symptoms by 28% to 40% of MS patients. OBJECTIVES: To assess whether carnitine (enteral or intrav...

B Systematic Review and Meta-analysis on Effect of Carnitine, Coenzyme Q10 and Selenium on Pregnancy and Semen Parameters in Couples With Idiopathic Male Infertility
Meta Analysis Urology 2022 n=3304

**Sharma et al., 2022** | Urology | Meta Analysis Sharma Aditya P, Sharma Gopal, Kumar Rajeev. Systematic Review and Meta-analysis on Effect of Carnitine, Coenzyme Q10 and Selenium on Pregnancy and Semen Parameters in Couples With Idiopathic Male Inf...

B Effects of Carnitine and Coenzyme Q10 on Sperm Quality and Pregnancy Rates in Men with Unexplained Infertility: A Systematic Review and Network Meta-Analysis
Systematic Review Reproductive sciences (Thousand Oaks, Calif.) 2025

AIMS: To study and explore the effects of oral Carnitine and Coenzyme Q10 on the quality of sperm and the rate of pregnancy in males with unexplained infertility. BACKGROUND: Preventing and reducing oxidative stress is essential for male infertility ...

B Efficacy and Effectiveness of Carnitine Supplementation for Cancer-Related Fatigue: A Systematic Literature Review and Meta-Analysis
Meta Analysis Nutrients 2017

BACKGROUND: Carnitine deficiency has been implicated as a potential pathway for cancer-related fatigue that could be treated with carnitine supplementation. The aim of this systematic literature review and meta-analysis was to evaluate the literature...

B Scientific Opinion on L-carnitine and energy metabolism
Regulatory Source EFSA Journal 2010

**Authority**: European Food Safety Authority (EFSA) **Claim Type**: art13.1 **Substance**: carnitine **DOI**: 10.2903/j.efsa.2010.1769 **URL**: https://doi.org/10.2903/j.efsa.2010.1769

B The Effect of Antioxidants on Sperm Quality Parameters and Pregnancy Rates for Idiopathic Male Infertility: A Network Meta-Analysis of Randomized Controlled Trials
Systematic Review Frontiers in endocrinology 2022 n=1917

**Li et al., 2022** | Front Endocrinol (Lausanne) | Systematic Review Li Kun-Peng, Yang Xue-Song, Wu Tao. The Effect of Antioxidants on Sperm Quality Parameters and Pregnancy Rates for Idiopathic Male Infertility: A Network Meta-Analysis of Randomize...

B Comparison of nutritional supplements in improving glycolipid metabolism and endocrine function in polycystic ovary syndrome: a systematic review and network meta-analysis
Systematic Review PeerJ 2023 n=2362

**Hu et al., 2023** | PeerJ | Systematic Review Hu Xinyin, Wang Wanyi, ... Huang Yuhua. Comparison of nutritional supplements in improving glycolipid metabolism and endocrine function in polycystic ovary syndrome: a systematic review and network meta...

B Safety and efficacy of L-carnitine supplementation in improving cardiac function of hemodialysis patients: a systematic review and meta-analysis
Meta Analysis International urology and nephrology 2025 n=426

PURPOSE: Heart failure is a significant complication among patients undergoing hemodialysis, often associated with left ventricular hypertrophy and dysfunction. L-carnitine, crucial for fatty acid metabolism, has shown promise in improving cardiac fu...

B Acetyl-L-carnitine for dementia
Systematic Review The Cochrane database of systematic reviews 2003

BACKGROUND: Dementia is a common mental health problem affecting 5% of those over 65. Various pathological processes are linked to memory impairment in dementia, particularly those affecting the cholinergic neurotransmitter system. Acetyl-l-carnitine...

C Nutraceuticals in Thyroidology: A Review of in Vitro, and in Vivo Animal Studies
Systematic Review Nutrients 2020

**Benvenga et al., 2020** | Nutrients | Systematic Review Benvenga Salvatore, Ferrari Silvia Martina, ... Fallahi Poupak. Nutraceuticals in Thyroidology: A Review of in Vitro, and in Vivo Animal Studies. Nutrients. 2020-May-08;12(5). doi:10.3390/nu12...

C Effects of Reducing L-Carnitine Supplementation on Carnitine Kinetics and Cardiac Function in Hemodialysis Patients: A Multicenter, Single-Blind, Placebo-Controlled, Randomized Clinical Trial
Rct Nutrients 2021

L-carnitine (LC) supplementation improves cardiac function in hemodialysis (HD) patients. However, whether reducing LC supplementation affects carnitine kinetics and cardiac function in HD patients treated with LC remains unclear. Fifty-nine HD patie...

C Myeloperoxidase, carnitine, and derivatives of reactive oxidative metabolites in heart failure with preserved versus reduced ejection fraction: A meta-analysis
Meta Analysis International journal of cardiology 2024

BACKGROUND: Understanding the pathophysiology of heart failure (HF) with preserved ejection fraction (HFpEF) continues to be challenging. Several inflammatory and metabolic biomarkers have recently been suggested to be involved in HFpEF. OBJECTIVES: ...

C Efficacy and Safety of L-Carnitine Treatment for Chronic Heart Failure: A Meta-Analysis of Randomized Controlled Trials
Meta Analysis BioMed research international 2017 n=17

Background. Whether additional benefit can be achieved with the use of L-carnitine (L-C) in patients with chronic heart failure (CHF) remains controversial. We therefore performed a meta-analysis of randomized controlled trials (RCTs) to evaluate the...

C Nutritional interventions for exercise-induced muscle damage: an umbrella review of systematic reviews and meta-analyses of randomized trials
Systematic Review Nutrition reviews 2024

**Talebi et al., 2024** | Nutr Rev | Systematic Review Talebi Sepide, Mohammadi Hamed, ... Djafarian Kurosh. Nutritional interventions for exercise-induced muscle damage: an umbrella review of systematic reviews and meta-analyses of randomized trials...

C L-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial
Rct The American journal of clinical nutrition 2007 n=32

BACKGROUND: Centenarians are characterized by weakness, decreasing mental health, impaired mobility, and poor endurance. L-Carnitine is an important contributor to cellular energy metabolism. OBJECTIVE: This study evaluated the efficacy of L-carnitin...

C Liver-Oriented Acute Metabolic Effects of A Low Dose of L-Carnitine under Fat-Mobilizing Conditions: Pilot Human Clinical Trial.
Rct Journal of nutritional science and vitaminology

The acute metabolic effect of low dosages of L-carnitine under fat-mobilizing conditions was investigated. Healthy subjects (Study 1: n=5; Study 2: n=6) were asked to fast overnight. Then, 30 min of aerobic exercise on a cycle ergometer was performed...

C Short-term effects of a green coffee extract-, Garcinia c ambogia- and L-carnitine-containing chewing gum on snack intake and appetite regulation
Rct European journal of nutrition 2018 n=57

**Bobillo et al., 2018** | Eur J Nutr | Rct Bobillo Cecilia, Finlayson Graham, ... Mayer Marcos A. Short-term effects of a green coffee extract-, Garcinia c ambogia- and L-carnitine-containing chewing gum on snack intake and appetite regulation. Eur ...

C Newborn screening for homocystinurias and methylation disorders: systematic review and proposed guidelines
Systematic Review Journal of inherited metabolic disease 2015

**Huemer et al., 2015** | J Inherit Metab Dis | Systematic Review Huemer Martina, Kožich Viktor, ... Blom Henk J. Newborn screening for homocystinurias and methylation disorders: systematic review and proposed guidelines. J Inherit Metab Dis. 2015-No...

C Effect of Antioxidants on Sperm Quality Parameters in Subfertile Men: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials
Systematic Review Advances in nutrition (Bethesda, Md.) 2022

**Su et al., 2022** | Adv Nutr | Systematic Review Su Liang, Qu Hua, ... Jiao Yong-Zheng. Effect of Antioxidants on Sperm Quality Parameters in Subfertile Men: A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials. Adv Nutr. 2...

C Effects of Chromium and Carnitine Co-supplementation on Body Weight and Metabolic Profiles in Overweight and Obese Women with Polycystic Ovary Syndrome: a Randomized, Double-Blind, Placebo-Controlled Trial
Rct Biological trace element research 2020

The primary aim of our study was to determine the influence of taking chromium plus carnitine on insulin resistance, with a secondary objective of evaluating the influences on lipid profiles and weight loss in overweight subjects with polycystic ovar...

C Efficacy and Safety of the Combination of Superoxide Dismutase, Alpha Lipoic Acid, Vitamin B12, and Carnitine for 12 Months in Patients with Diabetic Neuropathy.
Rct Nutrients

AIM: To investigate the efficacy of Superoxide Dismutase, Alpha Lipoic Acid, Acetyl L-Carnitine, and Vitamin B12 (B12) in one tablet in Diabetic Neuropathy (DN). PATIENTS-METHODS: In this prospective, double-blind, placebo-controlled study, 85 patien...

C L-Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double-Blind, Placebo-Controlled Trial.
Rct Nutrients

UNLABELLED: L-carnitine tartrate has been shown to improve relatively short-term recovery among athletes. However, there is a lack of research on the longer-term effects in the general population. OBJECTIVE: The primary objectives of this randomized ...

C Effect of l-carnitine supplementation on liver fat content and cardiometabolic indices in overweight/obese women with polycystic ovary syndrome: A randomized controlled trial.
Rct Clinical nutrition ESPEN

BACKGROUND: Polycystic ovary syndrome (PCOS) is a common endocrine disorder among reproductive-age women, and is associated with cardiovascular diseases as well as non-alcoholic fatty liver disease. The recent evidence suggested the beneficial effect...

C Impact of Caloric Restriction and Exercise on Trimethylamine N-Oxide Metabolism in Women with Obesity.
Rct Nutrients

Trimethylamine N-oxide (TMAO) is linked to cardiovascular disease (CVD) through partly altered central hemodynamics. We sought to examine if a low-calorie diet plus interval exercise (LCD+INT) intervention reduces TMAO more than a low-calorie diet (L...

C Hydrogen-Rich Gas Enhanced Sprint-Interval Performance: Metabolomic Insights into Underlying Mechanisms.
Rct Nutrients

(1) Background: The diversity of blood biomarkers used to assess the metabolic mechanisms of hydrogen limits a comprehensive understanding of its effects on improving exercise performance. This study evaluated the impact of hydrogen-rich gas (HRG) on...

C l-Carnitine and Alpha-Lipoic Acid Fail to Improve Anaerobic and Aerobic Performance in Trained Cyclists Despite a Reduction in Blood Lactate Concentration.
Rct Nutrients

Background/Objectives: This study aimed to evaluate the effects of four weeks of combined Acetyl-l-Carnitine and alpha-lipoic acid (ALA) supplementation on anaerobic and aerobic performance and fatigue resistance in trained cyclists, hypothesizing im...

C The effects of concurrent Coenzyme Q10, L-carnitine supplementation in migraine prophylaxis: A randomized, placebo-controlled, double-blind trial
Rct Cephalalgia : an international journal of headache 2019

PURPOSE: The present study aimed to determine the effects of combined supplementation of Coenzyme Q10 with L-carnitine on mitochondrial metabolic disorders marker and migraine symptoms among migraine patients. METHODS: A total of 56 men and women, be...

C L-carnitine decreases myocardial injury in children undergoing open-heart surgery: A randomized controlled trial
Rct European journal of pediatrics 2024

Myocardial injury in open-heart surgery is related to several factors including ischemia-reperfusion injury, generation of reactive oxygen species, increased production of inflammatory mediators, and enhancement of apoptosis of cardiomyocytes. The ai...

C Study on propionyl-L-carnitine in chronic heart failure
Rct European heart journal 1999 n=266

AIMS: In patients with chronic heart failure, fatigue is independent of haemodynamic and neuroendocrine changes and possibly may be due to impaired muscle metabolism. Propionyl-L-carnitine, a carnitine derivative, was shown in previous studies to imp...

C Effect of whey protein-derived decapeptide on mood status and blood variables in healthy adults: a randomized, double-blind, placebo-controlled cross-over trial.
Rct European journal of nutrition

PURPOSE: The importance of maintaining good mental health with overall well-being has recently drawn attention from various fields. Functional peptides found from various protein sources reportedly reduce mental health problems. We found a new decape...

C Skeletal muscle carnitine loading increases energy expenditure, modulates fuel metabolism gene networks and prevents body fat accumulation in humans
Rct The Journal of physiology 2013 n=6

**Stephens et al., 2013** | J Physiol | Rct Stephens Francis B, Wall Benjamin T, ... Greenhaff Paul L. Skeletal muscle carnitine loading increases energy expenditure, modulates fuel metabolism gene networks and prevents body fat accumulation in human...

C Dietary Reference Intakes: L-Carnitine
Regulatory Source IOM/NAM Dietary Reference Intakes 2000

**Source**: IOM 2005 Dietary Reference Intakes for L-Carnitine **Unit**: mg/day No established DRI; typical supplemental dose 500-2000 mg/day These values are from the National Academy of Medicine (formerly Institute of Medicine) Dietary Reference In...

C Carnitine does not improve weight loss outcomes in valproate-treated bipolar patients consuming an energy-restricted, low-fat diet
Rct Bipolar disorders 2006

OBJECTIVES: Carnitine deficiency impairs fatty acid beta-oxidation and may partly explain weight gain in valproate-treated patients. The aim of this study was to determine whether l-carnitine supplementation improves weight loss outcomes in bipolar p...

C Acetyl L-carnitine (ALC) treatment in elderly patients with fatigue
Rct Archives of gerontology and geriatrics 2008

Fatigue is one of the conditions most frequently complained by the elderly. There are few effective treatment options for patients with chronic fatigue syndrome. To determine the efficacy, tolerability and impact on the fatigue, as well as on cogniti...

C L-Carnitine in the treatment of fatigue in adult celiac disease patients: a pilot study
Rct Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver 2007

BACKGROUND: Fatigue is common in celiac disease. L-Carnitine blood levels are low in untreated celiac disease. L-Carnitine therapy was shown to improve muscular fatigue in several diseases. AIM: To evaluate the effect of L-carnitine treatment in fati...

C Hyperthyroidism: Methimazole Plus L-carnitine and Selenium
Clinical Trial ClinicalTrials.gov 2021

**NCT ID**: NCT04946123 **Phase**: NA **Status**: COMPLETED **Enrollment**: 60 **Completion**: 2025-06-04

C L-Carnitine Supplementation, Rate of Weight Gain and EED in Children With SAM
Clinical Trial ClinicalTrials.gov 2021

**NCT ID**: NCT05083637 **Phase**: NA **Status**: COMPLETED **Enrollment**: 98 **Completion**: 2023-03-30

C Impact of Hemodialysis on Plasma Carnitine Levels in Patients With End Stage Renal Disease
Clinical Trial ClinicalTrials.gov 2023

**NCT ID**: NCT05817799 **Phase**: PHASE2 **Status**: COMPLETED **Enrollment**: 83 **Completion**: 2023-07-10

C Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging
Rct Urology 2004 n=120

**Cavallini et al., 2004** | Urology | Rct Cavallini G, Caracciolo S, ... Biagiotti G. Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging. Urology. 2004-Apr;63(4):64...

C Mediterranean diet intervention in overweight and obese subjects lowers plasma cholesterol and causes changes in the gut microbiome and metabolome independently of energy intake.
Rct Gut

OBJECTIVES: This study aimed to explore the effects of an isocaloric Mediterranean diet (MD) intervention on metabolic health, gut microbiome and systemic metabolome in subjects with lifestyle risk factors for metabolic disease. DESIGN: Eighty-two he...

C A metabolomics-based molecular pathway analysis of how the sodium-glucose co-transporter-2 inhibitor dapagliflozin may slow kidney function decline in patients with diabetes.
Rct Diabetes, obesity & metabolism

AIM: To investigate which metabolic pathways are targeted by the sodium-glucose co-transporter-2 inhibitor dapagliflozin to explore the molecular processes involved in its renal protective effects. METHODS: An unbiased mass spectrometry plasma metabo...

C Liraglutide treatment in overweight and obese patients with type 1 diabetes: A 26-week randomized controlled trial; mechanisms of weight loss.
Rct Diabetes, obesity & metabolism

AIM: To investigate the effects of liraglutide treatment on glycaemic control and adipose tissue metabolism in overweight and obese people with type 1 diabetes (T1DM). RESEARCH DESIGN AND METHODS: A total of 84 adult overweight and obese patients wit...

C Whole egg consumption increases plasma choline and betaine without affecting TMAO levels or gut microbiome in overweight postmenopausal women.
Rct Nutrition research (New York, N.Y.)

As a crucial part of the symbiotic system, the gut microbiome is metabolically connected to many diseases and conditions, including cardiovascular diseases (CVD). Trimethylamine (TMA) is produced by gut bacteria from dietary choline, betaine, or L-ca...

C In older women, a high-protein diet including animal-sourced foods did not impact serum levels and urinary excretion of trimethylamine-N-oxide.
Rct Nutrition research (New York, N.Y.)

Diets including red meat and other animal-sourced foods may increase proteolytic fermentation and microbial-generated trimethylamine (TMA) and, subsequently, trimethylamine-N-oxide (TMAO), a metabolite associated with increased risk of cardiovascular...

Showing top 50 of 80 sources, sorted by quality score.

Related Supplements

Frequently Asked Questions

What is Carnitine and how does it work?

Carnitine is a nutrient that plays a vital role in energy metabolism and the transport of fatty acids. It helps your body move fats into cells to be used for energy production.

Can Carnitine help with diabetic neuropathy?

There is moderate evidence suggesting that Acetyl-L-carnitine may be effective in treating diabetic peripheral neuropathy. This specific form of the nutrient is being studied for its ability to manage this nerve-related complication.

Does Carnitine improve male fertility?

Moderate evidence indicates that combining Carnitine with CoQ10 may improve sperm quality and pregnancy rates in men experiencing unexplained infertility. This combination is often studied for its potential reproductive benefits.

Can Carnitine help with leg pain from poor circulation?

There is moderate evidence that Propionyl-L-carnitine may assist in managing symptoms of intermittent claudication, which is a symptom of peripheral arterial disease. This could potentially help manage pain caused by reduced blood flow to the limbs.

What is the recommended dose of Carnitine?

There is no established Dietary Reference Intake (DRI) for Carnitine, but typical supplemental doses range from 500 to 2,000 mg per day. You should consult a healthcare professional to determine the appropriate dose for your needs.

Is Carnitine safe to take and are there any drug interactions?

There are currently no documented drug interactions or specific contraindications for Carnitine in the available research. However, you should always consult a doctor before starting a new supplement to ensure it is safe for your specific health profile.

Can Carnitine help with cancer-related fatigue?

There is moderate evidence suggesting that addressing Carnitine deficiency may be a potential pathway for treating fatigue in cancer patients. It is being investigated for its role in managing fatigue related to cancer treatment.

Answers generated from research evidence. Not medical advice.