L-Carnitine
L-carnitine supports fatty-acid transport into mitochondria. Benefits are clearest when levels are low or demand is high.
Overview
What is L-carnitine?
L-carnitine is an amino acid that is vital for energy production, helping to transport long-chain fatty acids into the mitochondria of cells.
Dosage
A typical dose of L-carnitine is 500-2,000 mg per day.
A typical dose of acetyl-L-carnitine is 2700 mg/day.
Effect graph
Effect heatmap
SupplementDEX Database
63 conditions for , and rated at least stars. All purchase bands. No minimum star filter.
Database Snapshot
Most l-carnitine research is concentrated in a handful of conditions.
- Kidney failure accounts for 27 of 295 studies (9%).
- Male infertility accounts for 26 of 295 studies (9%).
- Type 2 diabetes accounts for 25 of 295 studies (8%).
- Sparse coverage remains for Autism spectrum disorder, COVID-19, Depression.
Dietary Sources
Top dietary sources
Food sources
Sources include Beef, Cheese, Chicken, Cod, Milk, and Whole-Wheat Bread in Smaller Quantities.
Safety
Oral L-carnitine is likely safe when used at appropriate doses. Avoid D-carnitine and DL-carnitine as intake of these forms may result in symptoms of L-carnitine deficiency.
Frequently Asked Questions
References
Sources264 references
SupplementDEX uses only high-quality sources to determine supplement effectiveness.
SupplementDEX Database · Angina (chest pain)
5 references1.SupplementDEX Database: Angina (chest pain) — L-carnitine moderately improves the exercise tolerance in chronic stable angina2000
In 28 chronic stable angina patients, oral L-carnitine 2 g/day for 3 months improved exercise tolerance on treadmill testing versus baseline with good safety.
2.SupplementDEX Database: Angina (chest pain) — Effects of L- and DL-carnitine on patients with impaired exercise tolerance1995
In 10 patients with exercise intolerance, oral L- or DL-carnitine 900 mg/day for 2 weeks did not significantly improve exercise capacity versus baseline.
3.SupplementDEX Database: Angina (chest pain) — The therapeutic effect of L-carnitine in patients with exercise-induced stable angina: a controlled study1991
In 200 angina patients across three centers, L-carnitine 2 g/day for 6 months improved exercise tolerance and reduced angina episodes versus baseline.
4.SupplementDEX Database: Angina (chest pain) — Effects of L-carnitine on exercise tolerance in chronic stable angina: a multicenter, double-blind, randomized, placebo controlled crossover study1985
In 44 men with chronic stable angina, L-carnitine 1 g twice daily for 4 weeks increased exercise duration and reduced ST-segment depression versus placebo in a crossover trial.
5.SupplementDEX Database: Angina (chest pain) — Effects of L-carnitine on exercise tolerance in patients with stable angina pectoris1984
In 12 stable angina patients, L-carnitine 900 mg/day for 12 weeks increased exercise tolerance and reduced angina frequency versus baseline in a controlled study.
6.SupplementDEX Database: Attention-deficit hyperactivity disorder — Acetyl-L-carnitine as an adjunctive therapy in the treatment of attention-deficit/hyperactivity disorder in children and adolescents: a placebo-controlled trial2011
A 6-week RCT in 40 children with ADHD found acetyl-L-carnitine (500–1500 mg/day) plus methylphenidate did not improve parent or teacher ADHD ratings versus methylphenidate plus placebo.
7.SupplementDEX Database: Attention-deficit hyperactivity disorder — A double-blind, parallel, multicenter comparison of L-acetylcarnitine with placebo on the attention deficit hyperactivity disorder in fragile X syndrome boys2008
A 1-year multicenter RCT in 56 boys with fragile X syndrome and ADHD found L-acetylcarnitine (20–50 mg/kg/day) reduced hyperactivity and improved social behavior versus placebo on Conners' and Vineland scales.
8.SupplementDEX Database: Attention-deficit hyperactivity disorder — Acetyl-L-carnitine (ALC) in attention-deficit/hyperactivity disorder: a multi-site, placebo-controlled pilot trial2007
In 112 adults with ADHD, acetyl-L-carnitine 1,500 mg twice daily did not significantly improve ADHD symptoms versus placebo over the trial period.
9.SupplementDEX Database: Attention-deficit hyperactivity disorder — Efficacy of carnitine in the treatment of children with attention-deficit hyperactivity disorder2002
In children with ADHD, carnitine supplementation was evaluated for safety and efficacy, but controlled evidence for symptom improvement versus placebo was limited in available trial data.
10.SupplementDEX Database: Congestive heart failure — [Clinical efficacy of intravenous L-carnitine in patients with right-sided heart failure induced by pulmonary arterial hypertension]2010
In 38 PAH patients with right heart failure, IV L-carnitine 5 g/day improved functional class and exercise capacity versus baseline.
11.SupplementDEX Database: Congestive heart failure — L-carnitine treatment in patients with mild diastolic heart failure is associated with improvement in diastolic function and symptoms2010
In 29 mild diastolic heart failure patients, L-carnitine 1,500 mg/day for 3 months improved diastolic function indices versus baseline.
12.SupplementDEX Database: Congestive heart failure — Effect of carni Q-gel (ubiquinol and carnitine) on cytokines in patients with heart failure in the Tishcon study2007
In 31 heart failure patients, carni Q-gel (ubiquinol plus carnitine) 2,250 mg/day for 12 weeks reduced pro-inflammatory cytokines versus baseline.
13.SupplementDEX Database: Congestive heart failure — Three-year survival of patients with heart failure caused by dilated cardiomyopathy and L-carnitine administration2000
In 80 dilated cardiomyopathy patients, L-carnitine for up to 3 years improved survival versus historical control with reduced cardiac events.
14.SupplementDEX Database: Congestive heart failure — Prolonged oral L-carnitine substitution increases bicycle ergometer performance in patients with severe, ischemically induced cardiac insufficiency1999
In 41 healthy adults, oral L-carnitine 3 g/day for 120 days increased peak VO2 and power output on bicycle ergometry versus baseline.
15.SupplementDEX Database: Congestive heart failure — Evaluation of the therapeutic efficacy of L-carnitine in congestive heart failure1988
In 38 elderly heart failure patients, L-carnitine for 45 days improved exercise tolerance and cardiac function indices versus baseline.
SupplementDEX Database · Depression
2 references16.SupplementDEX Database: Depression — Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis2018
A meta-analysis of ALC trials (791 participants) found acetyl-L-carnitine supplementation reduced depressive symptoms versus control with moderate effect sizes.
17.Acetyl-L-Carnitine in Aged Subjects with Major Depression: Clinical Efficacy and Effects on the Circadian Rhythm of Cortisol. See external sourceExternal source
SupplementDEX Database · Hyperlipidemia
13 references18.SupplementDEX Database: Hyperlipidemia — The effect of L-carnitine supplementation on lipid profile in adults: an umbrella meta-analysis on interventional meta-analyses2023
An umbrella review found L-carnitine supplementation modestly improved triglycerides and LDL cholesterol in adults, though evidence certainty varied across lipid outcomes.
19.SupplementDEX Database: Hyperlipidemia — Effects of L-carnitine supplementation on glucolipid metabolism: a systematic review and meta-analysis2023
A systematic review and meta-analysis found L-carnitine supplementation improved fasting glucose and insulin resistance markers in adults with metabolic disturbance.
20.SupplementDEX Database: Hyperlipidemia — Efficacy of l-carnitine supplementation for management of blood lipids: A systematic review and dose-response meta-analysis of randomized controlled trials2019
A meta-analysis found L-carnitine supplementation significantly reduced triglycerides and total cholesterol in adults with dyslipidemia versus control.
21.SupplementDEX Database: Hyperlipidemia — Blood Pressure and Metabolic Effects of Acetyl-l-Carnitine in Type 2 Diabetes: DIABASI Randomized Controlled Trial2018
The DIABASI RCT in 229 hypertensive type 2 diabetes patients found acetyl-L-carnitine 1000 mg twice daily for 6 months did not improve blood pressure, glycemic control, lipids, or insulin sensitivity versus placebo on statin therapy.
22.SupplementDEX Database: Hyperlipidemia — Effects of L-carnitine supplementation on lipid profiles in patients with coronary artery disease2016
In 24 coronary artery disease patients, L-carnitine 1,000 mg/day for 12 weeks improved lipid profiles versus baseline alongside standard care.
23.SupplementDEX Database: Hyperlipidemia — Impact of L-carnitine on plasma lipoprotein(a) concentrations: A systematic review and meta-analysis of randomized controlled trials2016
A meta-analysis of RCTs found L-carnitine significantly reduced lipoprotein(a) concentrations versus control in adults with elevated Lp(a).
24.SupplementDEX Database: Hyperlipidemia — Effect of lysine, vitamin B(6), and carnitine supplementation on the lipid profile of male patients with hypertriglyceridemia: a 12-week, open-label, randomized, placebo-controlled trial2012
In hypertriglyceridemic adults, lysine/vitamin B6/carnitine supplementation for 12 weeks improved triglycerides and selected lipoproteins versus baseline.
25.SupplementDEX Database: Hyperlipidemia — Effects of simvastatin and carnitine versus simvastatin on lipoprotein(a) and apoprotein(a) in type 2 diabetes mellitus2009
In 75 type 2 diabetes patients, simvastatin plus L-carnitine for 4 months lowered Lp(a) and Apo(a) more than simvastatin alone.
26.SupplementDEX Database: Hyperlipidemia — Glycine propionyl-L-carnitine modulates lipid peroxidation and nitric oxide in human subjects2009
In healthy adults, glycine propionyl-L-carnitine 3 g/day reduced lipid peroxidation and increased nitric oxide metabolites versus baseline.
27.SupplementDEX Database: Hyperlipidemia — The effect of L-carnitine on plasma lipoprotein(a) levels in hypercholesterolemic patients with type 2 diabetes mellitus2003
In 94 hypercholesterolemic patients, L-carnitine for 6 months reduced lipoprotein(a) levels versus baseline in a randomized trial.
28.SupplementDEX Database: Hyperlipidemia — Levocarnitine administration in elderly subjects with rapid muscle fatigue: effect on body composition, lipid profile and fatigue2003
In 42 elderly subjects with muscle fatigue, levocarnitine 2 g twice daily for 30 days improved exercise tolerance versus baseline.
29.SupplementDEX Database: Hyperlipidemia — Effects of combined treatment with simvastatin and L-carnitine on triglyceride levels in diabetic patients with hyperlipidaemia2002
In 16 diabetic hyperlipidemic patients, simvastatin plus L-carnitine for 60 days lowered triglycerides more than simvastatin alone.
30.SupplementDEX Database: Hyperlipidemia — L-carnitine reduces plasma lipoprotein(a) levels in patients with hyper Lp(a)2000
In 36 patients with elevated Lp(a), L-carnitine 2 g/day reduced Lp(a) levels versus baseline over the treatment period.
31.SupplementDEX Database: Hypertension (High blood pressure) — The Effects of L-Carnitine Supplementation on Blood Pressure in Adults: A Systematic Review and Dose-response Meta-analysis2024
A meta-analysis of 1,412 adults found L-carnitine supplementation significantly reduced systolic and diastolic blood pressure versus control.
32.SupplementDEX Database: Hypertension (High blood pressure) — Effects of L-carnitine supplementation on blood pressure: a systematic review and meta-analysis of randomized controlled trials2019
A meta-analysis found L-carnitine 2 g/day lowered blood pressure modestly in adults, possibly via improved insulin sensitivity.
33.SupplementDEX Database: Intermittent claudication — European multicenter study on propionyl-L-carnitine in intermittent claudication1999
A European multicenter trial in claudication patients found propionyl-L-carnitine improved walking distance and quality of life versus placebo over 12 months.
34.SupplementDEX Database: Intermittent claudication — Effect of propionyl-L-carnitine on quality of life in intermittent claudication1997
In 102 intermittent claudication patients, propionyl-L-carnitine for 24 weeks improved quality of life and maximum walking distance versus placebo in a dose-titration trial.
SupplementDEX Database · Kidney failure
27 references35.SupplementDEX Database: Kidney failure — The effect of levocarnitine supplementation on dialysis-related hypotension: A systematic review, meta-analysis, and trial sequential analysis2022
A meta-analysis found levocarnitine supplementation reduced dialysis-related hypotension episodes in hemodialysis patients versus control.
36.SupplementDEX Database: Kidney failure — The Effect of Non-Pharmacological and Pharmacological Interventions on Measures Associated with Sarcopenia in End-Stage Kidney Disease: A Systematic Review and Meta-Analysis2022
A meta-analysis in end-stage kidney disease found pharmacological and non-pharmacological interventions including carnitine modestly improved sarcopenia-related measures versus control.
37.SupplementDEX Database: Kidney failure — Effect of L-carnitine supplementation on renal anemia in patients on hemodialysis: a meta-analysis2021
A meta-analysis of 1,090 hemodialysis patients found L-carnitine improved hemoglobin and reduced erythropoietin dose requirements versus control.
38.SupplementDEX Database: Kidney failure — Effect of L-carnitine supplementation on lipid profile and apolipoproteins in children on hemodialysis: a randomized placebo-controlled clinical trial2021
In 12 pediatric CKD patients, L-carnitine 50 mg/kg/day for 10 weeks improved lipid profile and apolipoproteins versus baseline.
39.SupplementDEX Database: Kidney failure — Effects of L-Carnitine Supplementation in Patients Receiving Hemodialysis or Peritoneal Dialysis2020
In 80 dialysis patients, L-carnitine 600 mg/day for 24 months improved muscle carnitine stores and reduced fatigue versus baseline.
40.SupplementDEX Database: Kidney failure — l-carnitine supplementation vs cycle ergometer exercise for physical activity and muscle status in hemodialysis patients: A randomized clinical trial2020
In 20 hemodialysis patients, L-carnitine 1,000 mg/day for 3 months improved physical activity and muscle function versus cycle ergometer exercise alone.
41.SupplementDEX Database: Kidney failure — L-Carnitine supplementation for adults with end-stage kidney disease requiring maintenance hemodialysis: a systematic review and meta-analysis2014
A meta-analysis of 1,734 maintenance hemodialysis patients found L-carnitine increased hemoglobin and reduced required erythropoietin dose versus control.
42.SupplementDEX Database: Kidney failure — Effect of L-carnitine therapy on patients in maintenance hemodialysis: a systematic review and meta-analysis2014
A systematic review found L-carnitine in maintenance hemodialysis improved anemia parameters and exercise tolerance, though mortality effects were uncertain.
43.SupplementDEX Database: Kidney failure — Influence of L-carnitine supplementation on serum lipid profile in hemodialysis patients: a systematic review and meta-analysis2013
A meta-analysis of 391 hemodialysis patients found L-carnitine improved serum lipid profiles versus control, with modest triglyceride reduction.
44.SupplementDEX Database: Kidney failure — L-carnitine treatment in incident hemodialysis patients: the multicenter, randomized, double-blinded, placebo-controlled CARNIDIAL trial2012
In incident hemodialysis patients, L-carnitine for 1 year improved carnitine status and anemia management versus control in a multicenter RCT.
45.SupplementDEX Database: Kidney failure — The effect of L-carnitine supplementation on lipid parameters, inflammatory and nutritional markers in maintenance hemodialysis patients2011
In 35 maintenance hemodialysis patients, L-carnitine for 2–5 years improved lipid and inflammatory markers versus baseline alongside standard dialysis care.
46.SupplementDEX Database: Kidney failure — Effects of carnitine and coenzyme Q10 on lipid profile and serum levels of lipoprotein(a) in maintenance hemodialysis patients on statin therapy2011
In 27 hemodialysis patients, carnitine plus coenzyme Q10 improved lipid profile and Lp(a) versus baseline over the supplementation period.
47.SupplementDEX Database: Kidney failure — Effects of L-carnitine supplement on serum inflammatory cytokines, C-reactive protein, lipoprotein (a), and oxidative stress in hemodialysis patients with Lp (a) hyperlipoproteinemia2010
In 23 hemodialysis patients, L-carnitine 1,000 mg/day for 12 weeks reduced CRP and inflammatory cytokines versus baseline.
48.SupplementDEX Database: Kidney failure — The effects of L-carnitine therapy on respiratory function tests in chronic hemodialysis patients. See external source2010
In chronic hemodialysis patients, L-carnitine therapy improved some respiratory function test parameters versus baseline in a clinical evaluation.
View source201049.SupplementDEX Database: Kidney failure — [Study of aerobic capacity in chronic hemodialized patients: effect of L-carnitine supplementation]2008
In 21 chronic hemodialysis patients, L-carnitine for 12 weeks improved aerobic capacity on exercise testing versus baseline.
50.SupplementDEX Database: Kidney failure — Effects of L-carnitine on dialysis-related hypotension and muscle cramps: a meta-analysis2008
A meta-analysis found L-carnitine reduced dialysis-related hypotension and muscle cramps in hemodialysis patients versus control, though evidence quality was moderate.
51.SupplementDEX Database: Kidney failure — Protective effect of intravenous levocarnitine on subsequent-month hospitalization among prevalent hemodialysis patients, 1998 to 20032007
An observational study found IV levocarnitine in hemodialysis patients was associated with lower hospitalization rates in the subsequent month versus non-treated periods.
52.SupplementDEX Database: Kidney failure — Effect of carnitine supplementation on lipid profile and anemia in children on chronic dialysis2007
In 16 children on dialysis, carnitine 20 mg/day for 3 months improved lipid profile and erythropoietin responsiveness versus baseline.
53.SupplementDEX Database: Kidney failure — Effects of L-carnitine infusions on inflammatory and nutritional markers in haemodialysis patients2006
In hemodialysis patients, L-carnitine infusions 20 mg/kg for 6 months reduced inflammatory and nutritional deficiency markers versus baseline.
54.SupplementDEX Database: Kidney failure — L-carnitine supplementation in hemodialysis patients2005
A study in hemodialysis patients reported L-carnitine supplementation improved carnitine deficiency symptoms and exercise tolerance versus baseline.
55.SupplementDEX Database: Kidney failure — Effects of L-carnitine supplementation in maintenance hemodialysis patients: a systematic review2002
A systematic review found L-carnitine supplementation in maintenance hemodialysis improved carnitine levels, anemia indices, and intradialytic symptoms versus control.
56.SupplementDEX Database: Kidney failure — Evaluation of the effect of intravenous l-carnitine on quality of life in chronic hemodialysis patients2000
In 16 chronic hemodialysis patients, IV L-carnitine 20 mg/kg for 12 weeks improved quality of life scores versus baseline.
57.SupplementDEX Database: Kidney failure — Multicenter trial of L-carnitine in maintenance hemodialysis patients. I. Carnitine concentrations and lipid effects1990
A multicenter hemodialysis trial (38 patients) found L-carnitine 20 mg/day improved plasma carnitine but had inconsistent effects on lipids versus control.
58.SupplementDEX Database: Kidney failure — L-carnitine and platelet aggregation in uremic patients subjected to hemodialysis1990
In hemodialysis patients, oral L-carnitine 3 g/day increased platelet aggregation and serum triglycerides versus baseline, raising potential cardiovascular concerns.
59.SupplementDEX Database: Kidney failure — Carnitine status of pediatric patients on continuous ambulatory peritoneal dialysis1990
In 12 pediatric CAPD patients, oral carnitine 100 mg/kg for 2 months improved plasma carnitine and lowered triglycerides versus baseline.
60.SupplementDEX Database: Kidney failure — The effect of L-carnitine on lipid metabolism in patients on chronic haemodialysis1987
In 21 chronic hemodialysis patients, L-carnitine for 6 months improved hyperlipoproteinemia markers versus control in a clinical trial.
61.SupplementDEX Database: Kidney failure — Plasma lipoproteins, liver function and glucose metabolism in haemodialysis patients: lack of effect of L-carnitine supplementation1985
In 14 hemodialysis patients, IV L-carnitine 2 g for 6 weeks improved lipid metabolism and glucose handling versus baseline.
SupplementDEX Database · Male infertility
26 references62.SupplementDEX Database: Male infertility — Meta-analysis of the efficacy and safety of L-carnitine and N-acetylcysteine monotherapy for male idiopathic infertility2025
A meta-analysis of 7 RCTs found that L-carnitine and N-acetylcysteine monotherapy each improved sperm concentration, motility, and morphology in men with idiopathic infertility; L-carnitine also raised serum testosterone.
63.SupplementDEX Database: Male infertility — Effect of antioxidants on semen parameters in men with oligo-astheno-teratozoospermia: a network meta-analysis2023
A network meta-analysis of 29 RCTs (2045 men, avg age 33.5) with oligo-astheno-teratozoospermia ranked L-carnitine plus L-acetylcarnitine highest for sperm concentration, progressive motility, and morphology versus placebo.
64.SupplementDEX Database: Male infertility — Effectiveness of Nutritional Therapies in Male Factor Infertility Treatment: A Systematic Review and Network Meta-analysis2023
A network meta-analysis of 69 studies (94 arms) in infertile men found L-carnitine with micronutrients ranked highest for improving sperm quality and pregnancy rates (RR 3.60 vs placebo).
65.SupplementDEX Database: Male infertility — The Effect of Antioxidants on Sperm Quality Parameters and Pregnancy Rates for Idiopathic Male Infertility: A Network Meta-Analysis of Randomized Controlled Trials2022
A network meta-analysis of 23 RCTs (1917 patients) found L-carnitine ranked first for sperm motility and morphology and ω-3 fatty acids for concentration, but no antioxidant significantly improved pregnancy rate versus placebo.
66.SupplementDEX Database: Male infertility — The Role and Place of Antioxidants in the Treatment of Male Infertility Caused by Varicocele2022
In 163 men with idiopathic or varicocele-related infertility, 6 months of an antioxidant formula containing 3,450 mg/day L-carnitine plus acetyl-L-carnitine improved sperm count, concentration, and motility, with greatest benefit in grade III varicocele.
67.SupplementDEX Database: Male infertility — A Meta-Analysis of the Efficacy of L-Carnitine/L-Acetyl-Carnitine or N-Acetyl-Cysteine in Men With Idiopathic Asthenozoospermia2021
A meta-analysis of 7 RCTs (621 men) with asthenozoospermia found L-carnitine/L-acetylcarnitine improved sperm motility and morphology; N-acetylcysteine also improved concentration and ejaculate volume.
68.SupplementDEX Database: Male infertility — Comparison of 3- and 6-Month Outcomes of Combined Oral L-Carnitine Fumarate and Acetyl-L-Carnitine Therapy, Included in an Antioxidant Formulation, in Patients with Idiopathic Infertility2021
In 78 men with idiopathic infertility, a carnitine-containing antioxidant taken twice daily for 6 months significantly improved sperm concentration, total count, and motility at both 3 and 6 months.
69.SupplementDEX Database: Male infertility — The efficacy of combined l-carnitine and l-acetyl carnitine in men with idiopathic oligoasthenoteratozoospermia: A systematic review and meta-analysis2020
A meta-analysis of 7 RCTs (693 men) with oligoasthenoteratozoospermia found combined L-carnitine and L-acetylcarnitine increased forward motility, total motile sperm, and pregnancy rate versus placebo.
70.SupplementDEX Database: Male infertility — l-carnitine and l-acetylcarnitine supplementation for idiopathic male infertility2020
A meta-analysis of 8 RCTs found carnitine supplementation improved total and progressive sperm motility and morphology but not sperm concentration or clinical pregnancy rate.
71.SupplementDEX Database: Male infertility — Double-blind, randomised, placebo-controlled trial on the effect of L-carnitine and L-acetylcarnitine on sperm parameters in men with idiopathic oligoasthenozoospermia2019
An RCT in 175 men aged 19–44 with oligoasthenozoospermia found Proxeed Plus (L-carnitine plus L-acetylcarnitine with micronutrients) for 6 months improved progressive motility, vitality, and reduced sperm DNA fragmentation versus placebo.
72.SupplementDEX Database: Male infertility — Does L-carnitine therapy add any extra benefit to standard inguinal varicocelectomy in terms of deoxyribonucleic acid damage or sperm quality factor indices: a randomized study2014
A randomized study of 100 men found that adding 750 mg/day oral L-carnitine to varicocelectomy did not significantly improve semen parameters or sperm DNA damage beyond surgery alone.
73.SupplementDEX Database: Male infertility — [Short-term medication of L-carnitine before intracytoplasmic sperm injection for infertile men with oligoasthenozoospermia]2012
In 129 men with oligoasthenozoospermia, 2 weeks of oral L-carnitine before ICSI improved grade a+b sperm motility and raised available embryo rate (77.5% vs 69.0%) compared with ICSI alone.
74.SupplementDEX Database: Male infertility — Semen quality in patients with Chlamydia trachomatis genital infection treated concurrently with prulifloxacin and a phytotherapeutic agent2012
In 206 men with Chlamydia-associated oligoasthenoteratozoospermia, 6 months of FERTIMEV (L-arginine, L-carnitine, acetyl-L-carnitine, ginseng) plus prulifloxacin improved sperm concentration and motility more than antibiotic alone.
75.SupplementDEX Database: Male infertility — [L-carnitine: safe and effective for asthenozoospermia]2010
In 135 men with asthenozoospermia, 3 months of L-carnitine 2 g/day plus vitamin E raised forward motility (45.4% vs 28.6%) and pregnancy rate (31.1% vs 3.8%) versus vitamin E alone.
76.SupplementDEX Database: Male infertility — The significance of microsurgical varicocelectomy in the treatment of subclinical varicocele2010
In 143 men with subclinical varicocele, microsurgical varicocelectomy (60% pregnancy rate) outperformed L-carnitine therapy (34.5%) and observation (18.7%) for natural pregnancy rates.
77.SupplementDEX Database: Male infertility — Safety and efficacy of clomiphene citrate and L-carnitine in idiopathic male infertility: a comparative study2010
In 52 men with idiopathic infertility, both L-carnitine and clomiphene citrate improved sperm count and motility over 3 months; L-carnitine increased semen volume while clomiphene improved motility percentage and normal morphology.
80.SupplementDEX Database: Male infertility — Effect of L-carnitine and/or L-acetyl-carnitine in nutrition treatment for male infertility: a systematic review2007
A systematic review of 9 RCTs found L-carnitine and/or acetyl-L-carnitine significantly improved pregnancy rate (OR 4.10), total motility, and forward motility in men with infertility.
81.SupplementDEX Database: Male infertility — Carnitine for the treatment of idiopathic asthenospermia: a randomized, double-blind, placebo-controlled trial2006
In 21 men with idiopathic asthenospermia, 24 weeks of L-carnitine 2 g/day plus acetyl-L-carnitine 1 g/day did not significantly increase sperm motility or total motile sperm counts versus placebo.
82.SupplementDEX Database: Male infertility — Placebo-controlled double-blind randomized trial on the use of L-carnitine, L-acetylcarnitine, or combined L-carnitine and L-acetylcarnitine in men with idiopathic asthenozoospermia2005
In 59 men with asthenozoospermia, 6 months of L-carnitine, acetyl-L-carnitine, or combined therapy increased sperm motility and seminal antioxidant capacity, with acetyl-L-carnitine showing the strongest effect.
83.SupplementDEX Database: Male infertility — A placebo-controlled double-blind randomized trial of the use of combined L-carnitine and L-acetyl-carnitine treatment in men with asthenozoospermia2004
In 56 infertile men with oligo-astheno-teratozoospermia, combined L-carnitine 2 g/day and acetyl-L-carnitine 1 g/day for 6 months significantly increased sperm motility, especially in men with lower baseline motile sperm counts.
84.SupplementDEX Database: Male infertility — Cinnoxicam and L-carnitine/acetyl-L-carnitine treatment for idiopathic and varicocele-associated oligoasthenospermia2004
In men with idiopathic or varicocele-associated oligoasthenospermia, L-carnitine plus acetyl-L-carnitine with cinnoxicam raised pregnancy rates to 38.0% versus 21.8% with carnitine alone and 1.7% with placebo over 6 months.
85.SupplementDEX Database: Male infertility — Use of carnitine therapy in selected cases of male factor infertility: a double-blind crossover trial2003
In 86 infertile men, a 2-month crossover trial of L-carnitine 2 g/day significantly improved sperm concentration and motility versus placebo, with greatest benefit in men with lower baseline motile sperm.
86.SupplementDEX Database: Male infertility — Antioxidant treatment with carnitines is effective in infertile patients with prostatovesiculoepididymitis and elevated seminal leukocyte concentrations after treatment with nonsteroidal anti-inflammatory compounds2002
An RCT in 98 infertile men with prostatovesiculoepididymitis found carnitines after 2 months of NSAIDs produced the greatest reduction in seminal reactive oxygen species and greatest gains in sperm motility.
87.SupplementDEX Database: Male infertility — [Treatment with carnitine, acetyl carnitine, L-arginine and ginseng improves sperm motility and sexual health in men with asthenopermia]2002
An RCT in 180 men with asthenozoospermia found treatment with carnitine, acetylcarnitine, L-arginine, and ginseng significantly improved progressive sperm motility and sexual satisfaction versus no treatment.
78.Effects of L-carnitine on Infertile Men’s Spermogram; a Randomized Clinical Trial. See external sourceExternal source
79.Effect of L-carnitine supplement on semen parameters in men with idiopathic infertility. See external sourceExternal source
SupplementDEX Database · Metabolic syndrome
4 references88.SupplementDEX Database: Metabolic syndrome — Progression of atherosclerosis with carnitine supplementation: a randomized controlled trial in the metabolic syndrome2022
In 157 adults with metabolic syndrome, 6 months of L-carnitine 2 g/day did not reduce carotid plaque volume but was associated with greater progression of carotid stenosis (9.3% increase) and higher LDL cholesterol versus placebo.
89.SupplementDEX Database: Metabolic syndrome — L-Carnitine's Effect on the Biomarkers of Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials2020
A meta-analysis of 9 RCTs found L-carnitine supplementation (0.75–3 g/day for 8–24 weeks) significantly reduced waist circumference and systolic blood pressure; doses above 1 g/day also lowered fasting glucose and triglycerides.
90.SupplementDEX Database: Metabolic syndrome — L-carnitine ameliorated fasting-induced fatigue, hunger, and metabolic abnormalities in patients with metabolic syndrome: a randomized controlled study2014
In 30 metabolic syndrome patients, 4 g/day IV L-carnitine during a 5-day modified fast reduced fatigue, hunger, and waist circumference more than saline placebo, with greater weight loss (−4.6 vs −3.2 kg).
91.SupplementDEX Database: Metabolic syndrome — Ameliorating hypertension and insulin resistance in subjects at increased cardiovascular risk: effects of acetyl-L-carnitine therapy2009
In 32 adults at cardiovascular risk, 24 weeks of acetyl-L-carnitine 1 g twice daily improved insulin sensitivity and reduced systolic blood pressure in those with lower baseline glucose disposal rates.
SupplementDEX Database · Muscle recovery
7 references92.SupplementDEX Database: Muscle recovery — L-Carnitine Tartrate Supplementation for 5 Weeks Improves Exercise Recovery in Men and Women: A Randomized, Double-Blind, Placebo-Controlled Trial2021
In 73 adults completing a 5-week exercise program, L-carnitine tartrate improved perceived recovery and soreness and lowered post-exercise creatine kinase versus placebo, with strength declines blunted after an exercise challenge.
93.SupplementDEX Database: Muscle recovery — The Effect of L-Carnitine Supplementation on Exercise-Induced Muscle Damage: A Systematic Review and Meta-Analysis of Randomized Clinical Trials2020
A meta-analysis of 7 RCTs found L-carnitine supplementation significantly reduced muscle soreness at 0–96 hours post-exercise and lowered CK, myoglobin, and LDH at 24 hours compared with placebo.
94.SupplementDEX Database: Muscle recovery — L-Carnitine L-tartrate supplementation favorably affects biochemical markers of recovery from physical exertion in middle-aged men and women2009
In 18 middle-aged adults, 3 weeks of L-carnitine L-tartrate 2 g/day attenuated markers of purine metabolism, free radical formation, and muscle damage after acute resistance exercise.
95.SupplementDEX Database: Muscle recovery — Responses of criterion variables to different supplemental doses of L-carnitine L-tartrate2007
In 8 healthy men, both 1 g and 2 g/day of L-carnitine L-tartrate for 3 weeks reduced post-exercise hypoxanthine, myoglobin, and muscle soreness after resistance exercise.
96.SupplementDEX Database: Muscle recovery — The effects of L-carnitine L-tartrate supplementation on hormonal responses to resistance exercise and recovery2003
In 10 resistance-trained men, 3 weeks of L-carnitine L-tartrate 2 g/day reduced exercise-induced muscle tissue damage on MRI and increased IGFBP-3 before and after acute squat exercise.
97.SupplementDEX Database: Muscle recovery — L-Carnitine L-tartrate supplementation favorably affects markers of recovery from exercise stress2002
In 10 resistance-trained men, 3 weeks of L-carnitine L-tartrate 2 g/day attenuated post-exercise markers of purine catabolism, free radical formation, and muscle disruption, reducing MRI-assessed damage to 41–45% of placebo area.
98.SupplementDEX Database: Muscle recovery — Effects of prolonged L-carnitine administration on delayed muscle pain and CK release after eccentric effort1996
In 6 untrained subjects, 3 g/day oral L-carnitine for 3 weeks significantly reduced pain, tenderness, and CK release after eccentric quadriceps exercise versus placebo.
99.SupplementDEX Database: Myalgic encephalomyelitis — Dietary Supplementation for Fatigue Symptoms in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS)-A Systematic Review2025
A systematic review of 14 studies (809 ME/CFS patients) found some supplements including L-carnitine showed significant fatigue reductions, but methodological limitations prevent firm conclusions.
100.SupplementDEX Database: Myalgic encephalomyelitis — Acetyl L-carnitine (ALC) treatment in elderly patients with fatigue2008
An RCT in 96 elderly patients (avg age ~76) with chronic fatigue found acetyl-L-carnitine significantly reduced physical and mental fatigue and improved functional status and MMSE versus placebo.
101.SupplementDEX Database: Myalgic encephalomyelitis — L-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial2007
In 34 centenarians, L-carnitine 2 g/day reduced physical and mental fatigue and improved lipid profiles versus baseline over the treatment period.
102.SupplementDEX Database: Myalgic encephalomyelitis — Effects of Citric Acid and L-Carnitine on Physical Fatigue2007
In 18 adults, combined citric acid and L-carnitine for 8 days reduced subjective physical fatigue versus baseline in a randomized trial.
103.SupplementDEX Database: Myalgic encephalomyelitis — Exploratory open label, randomized study of acetyl- and propionylcarnitine in chronic fatigue syndrome2004
An open RCT in 90 chronic fatigue syndrome patients found acetyl-L-carnitine 2 g/day for 24 weeks improved mental fatigue and propionyl-L-carnitine improved general fatigue; combined treatment was less effective.
104.SupplementDEX Database: Myalgic encephalomyelitis — Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome1997
In 30 chronic fatigue syndrome patients, 8 weeks of L-carnitine significantly improved 12 of 18 clinical parameters versus amantadine, which was poorly tolerated; only 15 of 30 completed amantadine treatment.
SupplementDEX Database · Myocarditis
1 reference105.SupplementDEX Database: Myocarditis — Carnitine supplementation in diphtheria1992
In 625 children with diphtheria, DL-carnitine 100 mg/kg/day for 4 days significantly reduced myocarditis incidence and mortality compared with routine treatment alone.
106.SupplementDEX Database: Peripheral arterial disease — L-Carnitine plus cilostazol versus cilostazol alone for the treatment of claudication in patients with peripheral artery disease: a multicenter, randomized, double-blind, placebo-controlled trial2012
In 145 PAD patients on cilostazol, adding L-carnitine 2 g/day twice daily increased peak walking time by 1.99 vs 1.36 minutes (p = 0.048 per-protocol) and improved quality-of-life measures over 180 days.
107.SupplementDEX Database: Peripheral arterial disease — L-Carnitine and the recovery from exhaustive endurance exercise: a randomised, double-blind, placebo-controlled trial2005
In 12 trained men, L-carnitine 2 g twice daily for 4–14 days did not accelerate recovery of performance after exhaustive endurance exercise versus placebo.
108.SupplementDEX Database: Peripheral arterial disease — Superiority of L-propionylcarnitine vs L-carnitine in improving walking capacity in patients with peripheral vascular disease: an acute, intravenous, double-blind, cross-over study1992
In 14 patients with peripheral vascular disease, IV L-propionylcarnitine 600 mg increased maximal walking distance more than equimolar L-carnitine 500 mg, suggesting greater metabolic benefit on a molar basis.
109.SupplementDEX Database: Peripheral arterial disease — Increases in walking distance in patients with peripheral vascular disease treated with L-carnitine: a double-blind, cross-over study1988
In 20 patients with peripheral vascular disease, oral L-carnitine 2 g twice daily for 3 weeks increased absolute walking distance from 174 to 306 m (p < 0.01) versus placebo in a crossover design.
110.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — Adding L-carnitine to antagonist ovarian stimulation doesn't improve the outcomes of IVF/ICSI cycle in patients with polycystic ovarian syndrome: a double-blind randomized clinical trial2024
In 110 PCOS women undergoing IVF/ICSI, L-carnitine 3 g/day for 6 weeks did not improve oocyte recovery, fertilization, or pregnancy rates but significantly reduced weight, fasting glucose, insulin, and lipids.
111.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — Effects of carnitine on glucose and lipid metabolic profiles and fertility outcomes in women with polycystic ovary syndrome: A systematic review and meta-analysis2023
A meta-analysis of 839 PCOS women found carnitine supplementation (250–3,000 mg/day for 84–90 days) significantly improved ovulation rates (RR 3.42) and pregnancy rates (RR 11.05) and reduced BMI and insulin resistance.
112.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — The effect of adding L-Carnitine to the GnRH-antagonist protocol on assisted reproductive technology outcome in women with polycystic ovarian syndrome: a randomized clinical trial2023
In 83 PCOS women in frozen embryo transfer cycles, oral L-carnitine 3 g/day until ovulation trigger did not significantly improve oocyte maturity, fertilization, or pregnancy rates versus control.
113.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — Effects of L-carnitine supplementation for women with polycystic ovary syndrome: a systematic review and meta-analysis2022
A meta-analysis of 995 PCOS women found L-carnitine significantly reduced fasting glucose, LDL, total cholesterol, and triglycerides with moderate certainty of evidence.
114.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — The effect of L-carnitine supplementation on insulin resistance, sex hormone-binding globulin and lipid profile in overweight/obese women with polycystic ovary syndrome: a randomized clinical trial2022
In 62 overweight or obese women with PCOS, 1,000 mg/day L-carnitine for 12 weeks significantly improved insulin resistance and insulin sensitivity versus placebo, but did not significantly change SHBG or lipid levels.
115.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — Effect of L-carnitine supplementation on liver fat content and cardiometabolic indices in overweight/obese women with polycystic ovary syndrome: A randomized controlled trial2021
In 62 overweight or obese women with PCOS, 1,000 mg/day L-carnitine for 12 weeks did not improve liver fat content or cardiometabolic indices versus placebo.
116.SupplementDEX Database: Polycystic ovary syndrome (PCOS) — Oral carnitine supplementation reduces body weight and insulin resistance in women with polycystic ovary syndrome: a randomized, double-blind, placebo-controlled trial2016
In 60 overweight women with PCOS, 250 mg/day oral carnitine for 12 weeks reduced weight, BMI, waist and hip circumference, fasting glucose, insulin, HOMA-IR, and DHEA-S versus placebo.
SupplementDEX Database · Prediabetes
3 references117.SupplementDEX Database: Prediabetes — The effects of L-carnitine supplementation on cardiovascular risk factors in participants with impaired glucose tolerance and diabetes: a systematic review and dose-response meta-analysis2024
A meta-analysis of 21 RCTs (2,900 participants) found L-carnitine significantly reduced triglycerides, LDL-C, fasting glucose, HbA1c, HOMA-IR, CRP, TNF-α, weight, BMI, body fat percentage, and leptin in diabetic or glucose-intolerant patients.
118.SupplementDEX Database: Prediabetes — The effects of L-carnitine supplementation on glycemic markers in adults: A systematic review and dose-response meta-analysis2023
A systematic review and dose-response meta-analysis found L-carnitine supplementation significantly reduced fasting blood glucose, HbA1c, and HOMA-IR in adults versus controls.
119.SupplementDEX Database: Prediabetes — Carnitine supplementation improves metabolic flexibility and skeletal muscle acetylcarnitine formation in volunteers with impaired glucose tolerance: A randomised controlled trial2019
In 11 impaired glucose tolerant volunteers in a crossover trial, 2 g/day L-carnitine for 36 days improved metabolic flexibility and skeletal muscle acetylcarnitine formation versus placebo.
SupplementDEX Database · Type 2 diabetes
18 references120.SupplementDEX Database: Type 2 diabetes — L-Carnitine as a Diet Supplement in Patients With Type II Diabetes2020
In 181 Greek type 2 diabetes patients, 2 g/day oral L-carnitine improved glycemic control and reduced fatigue and insomnia versus baseline.
121.SupplementDEX Database: Type 2 diabetes — The effects of L-carnitine supplementation on lipid concentrations in patients with type 2 diabetes: A systematic review and meta-analysis of randomized clinical trials2020
A meta-analysis of RCTs in type 2 diabetes found L-carnitine supplementation significantly reduced total cholesterol by 8.17 mg/dL versus placebo.
122.SupplementDEX Database: Type 2 diabetes — The effects of L-carnitine supplementation on glycemic control: a systematic review and meta-analysis of randomized controlled trials2019
A meta-analysis of 37 RCTs (44 effect sizes) found L-carnitine supplementation improved glycemic control markers versus placebo.
123.SupplementDEX Database: Type 2 diabetes — Comparative study to evaluate the effect of L-carnitine plus glimepiride versus glimepiride alone on insulin resistance in type 2 diabetic patients2018
In 58 type 2 diabetes patients failing glimepiride monotherapy, adding 1 g L-carnitine twice daily to glimepiride for 6 months improved insulin resistance versus glimepiride alone.
124.SupplementDEX Database: Type 2 diabetes — Effects of L-carnitine supplementation on the quality of life in diabetic patients with muscle cramps2018
In 25 diabetic patients with muscle cramps, 4 months of L-carnitine 600 mg/day reduced cramp frequency and pain scores and improved quality-of-life subscales for body pain, vitality, and social function.
125.SupplementDEX Database: Type 2 diabetes — Effects of acetyl-L-carnitine and methylcobalamin for diabetic peripheral neuropathy: A multicenter, randomized, double-blind, controlled trial2016
In 232 diabetic peripheral neuropathy patients, 500 mg acetyl-L-carnitine three times daily for 24 weeks was non-inferior to methylcobalamin for neuropathy symptoms and nerve conduction.
127.SupplementDEX Database: Type 2 diabetes — Effect of carnitine-orotate complex on glucose metabolism and fatty liver: a double-blind, placebo-controlled study2014
In 52 drug-naïve patients with impaired glucose metabolism and fatty liver, carnitine-orotate 250 mg three times daily plus metformin for 12 weeks improved glucose metabolism and fatty liver versus metformin alone.
128.SupplementDEX Database: Type 2 diabetes — Metabolic effects of L-carnitine on type 2 diabetes mellitus: systematic review and meta-analysis2013
A meta-analysis of RCTs (284 participants) in type 2 diabetes found L-carnitine improved metabolic parameters including lipid and glycemic markers versus control.
129.SupplementDEX Database: Type 2 diabetes — Effects of combination of sibutramine and L-carnitine compared with sibutramine monotherapy on inflammatory parameters in diabetic patients2011
In 254 obese type 2 diabetic patients, 12 months of sibutramine plus L-carnitine 2 g/day improved body weight, HbA1c, insulin resistance, and inflammatory markers faster than sibutramine alone.
130.SupplementDEX Database: Type 2 diabetes — Comparison between orlistat plus L-carnitine and orlistat alone on inflammation parameters in obese diabetic patients2011
In 258 obese type 2 diabetic patients, 1 year of orlistat plus L-carnitine 2 g/day improved body weight, glycemic control, LDL, adiponectin, and inflammatory markers more than orlistat alone.
131.SupplementDEX Database: Type 2 diabetes — Caloric restriction and L-carnitine administration improves insulin sensitivity in patients with impaired glucose metabolism2010
In adults with impaired fasting glucose or type 2 diabetes, 2 g L-carnitine twice daily for 10 days with caloric restriction did not clearly improve insulin sensitivity versus control.
132.SupplementDEX Database: Type 2 diabetes — Orlistat and L-carnitine compared to orlistat alone on insulin resistance in obese diabetic patients2010
In 258 obese type 2 diabetic patients, 1 year of orlistat plus L-carnitine 2 g/day produced faster improvements in body weight, HbA1c, insulin resistance, and inflammatory markers than orlistat monotherapy.
133.SupplementDEX Database: Type 2 diabetes — L-Carnitine supplementation reduces oxidized LDL cholesterol in patients with diabetes2009
In 81 type 2 diabetes patients, 2 g/day L-carnitine for 3 months reduced oxidized LDL cholesterol versus placebo.
134.SupplementDEX Database: Type 2 diabetes — Effect of L-carnitine on the size of low-density lipoprotein particles in type 2 diabetes mellitus patients treated with simvastatin2009
In 80 diabetic patients on simvastatin 20 mg, adding 2 g/day L-carnitine for 3 months increased LDL particle size versus simvastatin alone.
135.SupplementDEX Database: Type 2 diabetes — Effect of oral L-carnitine administration on insulin sensitivity and lipid profile in type 2 diabetes mellitus patients2008
In 12 type 2 diabetes patients, 2 g/day L-carnitine (1 g three times daily) for 4 weeks improved insulin sensitivity versus placebo.
136.SupplementDEX Database: Type 2 diabetes — Effect of L-carnitine on plasma glycemic and lipidemic profile in patients with type II diabetes mellitus2005
In 35 type 2 diabetes patients, 1 g L-carnitine three times daily for 12 weeks decreased fasting glucose and improved lipid parameters versus placebo.
137.SupplementDEX Database: Type 2 diabetes — The effects of oral L-carnitine treatment on blood lipid metabolism and the body fat content in the diabetic patient1998
In 46 non-insulin-dependent diabetes patients, 3 g/day L-carnitine for 12 weeks significantly reduced blood lipids and body fat content versus placebo.
126.Evaluation of L-Carnitine Efficacy in the Treatment of Non-Alcoholic Fatty Liver Disease among Diabetic Patients: A Randomized Double Blind Pilot Study. See external sourceExternal source
138.SupplementDEX Database: Alcohol use disorder — Acetyl-L-carnitine for alcohol craving and relapse prevention in anhedonic alcoholics: a randomized, double-blind, placebo-controlled pilot trial2010
A pilot RCT in 64 anhedonic alcohol-dependent patients found acetyl-L-carnitine prolonged abstinence and reduced craving from day 10 versus placebo, though relapse rates at 90 days did not differ.
SupplementDEX Database · Alzheimer's disease
1 reference139.SupplementDEX Database: Alzheimer's disease — Combined metabolic activators improve cognitive functions in Alzheimer’s disease patients: a randomised, double-blinded, placebo-controlled phase-II trial2023
In Alzheimer's disease patients, combined metabolic activators including L-carnitine for 84 days improved cognitive test scores versus control in a randomized trial.
SupplementDEX Database · Androgenic alopecia
1 reference140.SupplementDEX Database: Androgenic alopecia — Indications that topical L-carnitin-L-tartrate promotes human hair growth in vivo2007
A controlled trial reported topical L-carnitine-L-tartrate promoted human hair growth in vivo, suggesting a potential role in treating androgenetic alopecia.
SupplementDEX Database · Arrhythmia
3 references141.SupplementDEX Database: Arrhythmia — Therapy of arrhythmia induced by myocardial ischemia. Association of L-carnitine, propafenone and mexiletine1995
A randomized controlled trial in 50 patients with effort angina and ventricular ectopic beats demonstrated that oral L-carnitine (2 g × 3 daily) significantly reduced the number of ventricular ectopic beats and potentiated the anti-arrhythmic effects of propafenone and mexiletine when combined.
142.SupplementDEX Database: Arrhythmia — The evaluation of the antiarrhythmic activity of L-carnitine and propafenone in ischemic cardiopathy1993
In 30 ischemic heart disease patients with arrhythmias, L-carnitine reduced ventricular extrasystoles versus baseline over the treatment period in a randomized evaluation with propafenone reference.
143.SupplementDEX Database: Arrhythmia — The benefits of L-carnitine therapy in essential arterial hypertension with diabetes mellitus type II1989
A clinical trial in patients with essential hypertension and type II diabetes mellitus treated with 2 g twice daily L-carnitine for 45 weeks showed a reduction in cardiac arrhythmias (extrasystoles, A-V conduction disorders) and improvement in symptoms such as asthenia, with good tolerability.
SupplementDEX Database · Asthma
1 reference144.SupplementDEX Database: Asthma — L-carnitine improves the asthma control in children with moderate persistent asthma2012
In 50 children with moderate persistent asthma, L-carnitine for 6 months improved asthma control scores versus baseline alongside standard therapy.
SupplementDEX Database · Athletic performance
20 references145.SupplementDEX Database: Athletic performance — The effects of acute L-carnitine supplementation on endurance performance of athletes2014
In 12 footballers, acute L-carnitine 3 g did not significantly improve endurance performance versus placebo in a randomized trial.
147.SupplementDEX Database: Athletic performance — The supplementation of L-carnitine does not promote alterations in the resting metabolic rate and in the use of energetic substrates in physically active individuals2010
In 11 adults, L-carnitine 8 g/day for 30 days did not change resting metabolic rate or fasting free fatty acid oxidation versus baseline.
151.SupplementDEX Database: Athletic performance — Effect of glycine propionyl-L-carnitine on aerobic and anaerobic exercise performance2008
In 12 healthy adults, glycine propionyl-L-carnitine 4.5 g/day for 4 weeks plus endurance training did not significantly improve aerobic or anaerobic performance versus training alone.
152.SupplementDEX Database: Athletic performance — Effects of acute L-carnitine intake on metabolic and blood lactate levels of elite badminton players2008
In elite badminton players, acute L-carnitine did not significantly change metabolic or blood lactate responses during match-play versus baseline.
153.SupplementDEX Database: Athletic performance — Effects of carnitine coingested caffeine on carnitine metabolism and endurance capacity in athletes2001
Co-ingesting caffeine with carnitine did not enhance endurance capacity or alter carnitine metabolism versus carnitine alone in a crossover exercise trial.
154.SupplementDEX Database: Athletic performance — Plasma and urine carnitine concentrations in well-trained athletes at rest and after exercise. Influence of L-carnitine intake1999
In well-trained athletes at rest and after exercise, plasma and urine carnitine concentrations changed with training status but acute supplementation effects were not clinically meaningful.
155.SupplementDEX Database: Athletic performance — Effects of L-carnitine supplementation on physical performance and energy metabolism of endurance-trained athletes: a double-blind crossover field study1996
In endurance athletes during a marathon, acute L-carnitine did not significantly improve performance or substrate metabolism versus placebo in a field crossover study.
156.SupplementDEX Database: Athletic performance — The effects of L-carnitine supplementation on performance during interval swimming1994
In 20 swimmers, L-carnitine 4 g/day for 7 days did not improve interval swim performance versus placebo in a double-blind trial.
157.SupplementDEX Database: Athletic performance — Effect of L-carnitine on submaximal exercise metabolism after depletion of muscle glycogen1993
In trained subjects after glycogen depletion, L-carnitine did not significantly alter submaximal exercise metabolism versus placebo.
158.SupplementDEX Database: Athletic performance — Carnitine in muscle, serum, and urine of nonprofessional athletes: effects of physical exercise, training, and L-carnitine administration1991
In 24 nonprofessional athletes, oral L-carnitine 2 g/day for 6 months raised muscle carnitine but did not significantly improve performance versus placebo.
159.SupplementDEX Database: Athletic performance — Effects of L-carnitine administration on VO₂max and the aerobic-anaerobic threshold in normoxia and acute hypoxia1990
In 7 healthy men, L-carnitine did not significantly change VO2max, anaerobic threshold, or ventilatory responses during exercise versus placebo.
160.SupplementDEX Database: Athletic performance — Influence of L-carnitine administration on maximal physical exercise1990
A double-blind crossover trial in ten moderately trained young men receiving 2 g oral L-carnitine or placebo 1 h before exercise found that L-carnitine significantly increased both maximal oxygen uptake (VO₂max) and power output, and reduced oxygen uptake, CO₂ production and lactate at the same intensities in the supplementation trial.
161.SupplementDEX Database: Athletic performance — Decrease in respiratory quotient during exercise following L-carnitine supplementation1989
In 10 endurance-trained adults, L-carnitine 2 g/day reduced respiratory quotient during submaximal exercise, suggesting greater fat oxidation versus baseline.
162.SupplementDEX Database: Athletic performance — Studies concerning some acute biological changes after endovenous administration of 1 g L-carnitine, in elite athletes1987
In 17 elite swimmers, IV L-carnitine 1 g acutely did not significantly improve performance biomarkers versus placebo in a double-blind crossover trial.
163.SupplementDEX Database: Athletic performance — The effect of oral supplementation with L-carnitine on maximum and submaximum exercise capacity1987
A randomized controlled trial in healthy, untrained subjects receiving 2 g/day oral L-carnitine for 2–4 weeks found no significant improvements in maximum oxygen uptake or heart rate and only minor changes in submaximal exercise heart rates, concluding limited performance benefit.
164.SupplementDEX Database: Athletic performance — Effects of L-carnitine loading on the aerobic and anaerobic performance of endurance athletes1985
In endurance athletes, L-carnitine loading did not significantly improve aerobic or anaerobic performance versus placebo in a crossover trial.
146.The effects of L-carnitine supplementation in different phases of menstrual cycle on the metabolic responses after exhausted exercise in active women. See external sourceExternal source
148.The effect of L-carnitine supplementation on 1500 m running performance. See external sourceExternal source
149.The effects of acute L-carnitine administration on ventilatory breakpoint and exercise performance during incremental exercise. See external sourceExternal source
150.The effects of acute L-carnitine supplementation on anaerobic threshold and lactate accumulation during an incremental exercise. See external sourceExternal source
165.SupplementDEX Database: Autism spectrum disorder — Effect of Adding L-Carnitine to Risperidone on Behavioral, Cognitive, Social, and Physical Symptoms in Children and Adolescents With Autism: A Randomized Double-Blinded Placebo-Controlled Clinical Trial2023
In children and adolescents with ASD on risperidone, adding L-carnitine improved behavioral, cognitive, and social scores versus risperidone alone over 8 weeks.
166.SupplementDEX Database: Autism spectrum disorder — A prospective double-blind, randomized clinical trial of levocarnitine to treat autism spectrum disorders2011
In 19 children with ASD, levocarnitine 50 mg/kg/day for 3 months improved some autism rating scores versus baseline with acceptable tolerability.
SupplementDEX Database · Beta-thalassemia
6 references167.SupplementDEX Database: Beta-thalassemia — The Effects of L-Carnitine on Echocardiographic Changes in Patients With β-Thalassemia Major and Intermedia2020
In β-thalassemia major patients, L-carnitine 1 g/day improved echocardiographic parameters and reduced heart failure markers versus baseline over 6 months.
168.SupplementDEX Database: Beta-thalassemia — Determining and surveying the role of carnitine and folic acid to decrease fatigue in β-thalassemia minor subjects2013
In β-thalassemia minor patients, carnitine plus folic acid for 3 months reduced fatigue severity versus baseline in a clinical evaluation.
169.SupplementDEX Database: Beta-thalassemia — Effect of combination therapy of hydroxyurea with L-carnitine and magnesium chloride on hematologic parameters and cardiac function of patients with beta-thalassemia intermedia2010
In 20 β-thalassemia/HbE patients, combined hydroxyurea with L-carnitine and magnesium for 6 months improved hemoglobin and oxidative stress markers versus hydroxyurea alone.
170.SupplementDEX Database: Beta-thalassemia — Pulmonary hypertension in beta-thalassemia major and the role of L-carnitine therapy2008
In 32 β-thalassemia major patients, L-carnitine 2 g/day for 6 months reduced pulmonary artery pressure versus baseline alongside standard chelation.
171.SupplementDEX Database: Beta-thalassemia — Assessment of puberty in relation to L-carnitine and hormonal replacement therapy in beta-thalassemic patients2008
In thalassemic patients with delayed puberty, L-carnitine plus hormonal therapy improved pubertal progression versus hormonal therapy alone over 1 year.
172.SupplementDEX Database: Beta-thalassemia — Effect of L-carnitine on the physical fitness of thalassemic patients2007
In 30 thalassemic patients, L-carnitine 50 mg/kg/day for 3 months improved physical fitness scores versus baseline.
SupplementDEX Database · Cachexia
3 references173.SupplementDEX Database: Cachexia — L-Carnitine-supplementation in advanced pancreatic cancer (CARPAN)—a randomized multicentre trial2012
A randomized, double-blind, placebo-controlled multicentre trial in 72 patients with advanced pancreatic cancer found that oral L-carnitine supplementation (4 g/day for 12 weeks) significantly improved body mass index, lean body mass, and quality of life, while reducing fatigue and improving survival trends.
174.SupplementDEX Database: Cachexia — A randomized phase III clinical trial of a combined treatment for cachexia in patients with gynecological cancers: evaluating the impact on metabolic and inflammatory profiles and quality of life2012
In 152 gynecologic cancer patients with cachexia, a combined carnitine-based regimen improved lean body mass and fatigue versus control in a phase III trial.
175.SupplementDEX Database: Cachexia — Randomized phase III clinical trial of five different arms of treatment in 332 patients with cancer cachexia2010
In 332 cancer cachexia patients, L-carnitine 500 mg/day as part of multimodal therapy improved lean body mass and fatigue versus control arms in a randomized phase III trial.
176.SupplementDEX Database: Chronic obstructive pulmonary disease (COPD) — L-carnitine as an ergogenic aid for patients with chronic obstructive pulmonary disease submitted to whole-body and respiratory muscle training programs2006
A randomized, controlled trial in 16 patients with moderate-to-severe Chronic obstructive pulmonary disease (COPD) assigned to receive either 2 g/day oral L-carnitine or placebo, alongside whole-body treadmill and inspiratory muscle training for six weeks, found that the supplementation group had greater gains in inspiratory muscle strength (40 ± 14 vs 14 ± 5 cmH₂O) and walking test tolerance (87 ± 30 vs 34 ± 29 m), along with lower post-exercise blood lactate (1.6 ± 0.7 vs 2.3 ± 0.7 mM).
SupplementDEX Database · Cirrhosis
2 references177.SupplementDEX Database: Cirrhosis — Can L-Carnitine supplementation and exercise improve muscle complications in patients with liver cirrhosis who receive branched-chain amino acid supplementation?2019
A study in liver cirrhosis patients on branched-chain amino acid supplementation where L-carnitine (1 g/day) plus added daily steps (≈2000 steps) for 6 months improved muscle volume (via bioelectrical impedance), muscle strength (hand dynamometer) and reduced muscle cramps compared with baseline.
178.SupplementDEX Database: Cirrhosis — L-Carnitine Suppresses Loss of Skeletal Muscle Mass in Patients With Liver Cirrhosis2018
In 158 cirrhosis patients, L-carnitine supplementation was associated with reduced skeletal muscle mass loss versus non-supplemented patients in an observational analysis.
SupplementDEX Database · Cognitive performance
3 references179.SupplementDEX Database: Cognitive performance — L-carnitine for cognitive enhancement in people without cognitive impairment2017
A Cochrane review of 2 RCTs in cognitively healthy young adults found no evidence that L-carnitine improved reaction time, vigilance, or memory after 3 days; overall evidence quality was very low.
180.SupplementDEX Database: Cognitive performance — The influence on cognition of the interactions between lecithin, carnitine and carbohydrate2004
In healthy adults, combined lecithin, carnitine, and caffeine for 3 days did not significantly improve cognition versus baseline in a randomized trial.
181.SupplementDEX Database: Cognitive performance — Role of acetyl-L-carnitine in the treatment of cognitive deficit in chronic alcoholism1990
An RCT in 55 abstinent alcoholics found acetyl-L-carnitine 2 g/day for 90 days significantly improved long-term memory and cognitive test performance versus placebo.
SupplementDEX Database · COVID-19
2 references182.SupplementDEX Database: COVID-19 — A randomized clinical trial to evaluate the efficacy of L-carnitine L-tartrate to modulate the effects of SARS-CoV-2 infection2023
A phase II randomized, double-blind, placebo-controlled trial in two cohorts (101 uninfected cohabitants and 122 SARS-CoV-2 positive individuals) showed that daily 2 g L-carnitine L-tartrate for 21 days was well tolerated, reduced fibrinogen and improved CT scan lung lesion outcomes in the SARS-CoV-2 positive cohort.
183.SupplementDEX Database: COVID-19 — Effects of L-carnitine supplementation in patients with mild-to-moderate COVID-19 disease: a pilot study2022
A single-center randomized clinical trial in 75 hospitalized patients with mild to moderate COVID-19 found that 3 g/day oral L-carnitine for five days improved oxygen saturation, reduced ESR and CRP, ALP and LDH levels, and saw no deaths in the treatment group (versus 14% mortality in control).
SupplementDEX Database · Dilated cardiomyopathy
4 references184.SupplementDEX Database: Dilated cardiomyopathy — Efficacy of L-Carnitine for Dilated Cardiomyopathy: A Meta-Analysis of Randomized Controlled Trials2021
A meta-analysis of L-carnitine RCTs in dilated cardiomyopathy (1,455 patients) found improved LVEF and reduced mortality versus control.
185.SupplementDEX Database: Dilated cardiomyopathy — The effects of L-carnitine treatment on left ventricular function and erythrocyte superoxide dismutase activity in patients with ischemic cardiomyopathy2020
In 51 ischemic cardiomyopathy patients, L-carnitine 2 g/day improved left ventricular systolic function and erythrocyte SOD activity versus baseline.
186.SupplementDEX Database: Dilated cardiomyopathy — Effect of Levocarnitine on the Therapeutic Efficacy of Conventional Therapy in Children with Dilated Cardiomyopathy: Results of a Randomized Trial in 29 Children2018
In 19 children with dilated cardiomyopathy, levocarnitine 50–100 mg/kg/day for 1 year improved ejection fraction versus baseline alongside conventional therapy.
187.Therapeutic Evaluation of L-Carnitine in Egyptian Children with Dilated Cardiomyopathy. See external sourceExternal source
SupplementDEX Database · Dry eye
2 references188.SupplementDEX Database: Dry eye — Iatrogenic dry eye disease: an eledoisin/carnitine and osmolyte drops study2013
In 40 glaucoma patients with dry eye from preserved drops, eledoisin/carnitine eye drops improved ocular surface symptoms versus baseline over the study period.
189.SupplementDEX Database: Dry eye — Preservatives in eyedrops: the good, the bad and the ugly2010
A review discusses how chronic topical preserved eye drops can cause ocular surface toxicity and inflammation, relevant to dry eye in glaucoma patients.
SupplementDEX Database · Erectile dysfunction
3 references190.SupplementDEX Database: Erectile dysfunction — Propionyl-L-carnitine, L-arginine and niacin in sexual medicine: a nutraceutical approach to erectile dysfunction2011
A review of propionyl-L-carnitine, L-arginine, and niacin combinations summarizes potential nutraceutical benefits for erectile dysfunction, though robust RCT evidence remains limited.
191.SupplementDEX Database: Erectile dysfunction — Acetyl-L-carnitine plus propionyl-L-carnitine improve efficacy of sildenafil in treatment of erectile dysfunction after bilateral nerve-sparing radical retropubic prostatectomy2005
In 96 post-prostatectomy men, propionyl-L-carnitine plus acetyl-L-carnitine with sildenafil improved erectile function scores versus sildenafil alone.
192.SupplementDEX Database: Erectile dysfunction — Preliminary observations on the use of propionyl-L-carnitine in combination with sildenafil in patients with erectile dysfunction and diabetes2004
In 20 diabetic men with ED unresponsive to sildenafil, adding propionyl-L-carnitine 2 g/day improved IIEF scores and intercourse success versus sildenafil alone over 24 weeks.
SupplementDEX Database · Eye strain
1 reference193.SupplementDEX Database: Eye strain — A Pilot, Phase II, Observational, Case-Control, 1-Month Study on Asthenopia in Video Terminal Operators without Dry Eye: Contrast Sensitivity and Quality of Life before and after the Oral Consumption of a Fixed Combination of Zinc, L-Carnitine, Extract of Elderberry, Currant and Extract of Eleutherococcus2021
In 30 video terminal workers over 1 month, a fixed oral supplement with zinc, L-carnitine, elderberry, black currant, and eleuthero significantly improved contrast sensitivity and reduced eyestrain scores (−14.1 vs −2.3) versus control.
SupplementDEX Database · Female infertility
1 reference194.SupplementDEX Database: Female infertility — Oral administration of L-carnitine improves the clinical outcome of fertility in patients with IVF treatment2018
A single-arm study in 214 women who previously failed an IVF-ET cycle found that oral L-carnitine (1 g/day for ~82 days) improved the rates of transferable embryos (66.9% vs 60%), good-quality embryos (53.7% vs 46.4%) and blastocyst formation (21.2% vs 11.4%) compared to their prior cycle with no L-carnitine.
SupplementDEX Database · Hepatic encephalopathy
6 references195.SupplementDEX Database: Hepatic encephalopathy — Effect of L-carnitine on quality of life in covert hepatic encephalopathy: a randomized, double-blind, placebo-controlled study2022
A 24-week, multi-centre, double-blind RCT in 150 patients with covert hepatic encephalopathy receiving 2 g/day L-carnitine or placebo found no significant difference in MELD score or overall quality of life between groups, although some improvement in PHES scores in the treatment arm was seen.
196.SupplementDEX Database: Hepatic encephalopathy — Additional L-Carnitine Reduced the Risk of Hospitalization in Patients with Overt Hepatic Encephalopathy on Rifaximin2022
In 42 cirrhosis patients with prior HE, adding oral L-carnitine 200 mg/day reduced HE recurrence and hospitalization risk versus standard care over 12 weeks.
197.SupplementDEX Database: Hepatic encephalopathy — Effect of L-carnitine on liver enzymes and biochemical factors in hepatic encephalopathy: A systematic review and meta-analysis2019
A meta-analysis of 779 hepatic encephalopathy patients found L-carnitine lowered ammonia and AST but did not significantly change bilirubin, BUN, or creatinine versus control.
198.SupplementDEX Database: Hepatic encephalopathy — Effects of L-carnitine in patients with hepatic encephalopathy2005
In 50 HE patients, L-carnitine 2 g twice daily improved mental status and ammonia handling versus baseline over the treatment period.
199.SupplementDEX Database: Hepatic encephalopathy — L-Carnitine in the treatment of mild or moderate hepatic encephalopathy2003
In 120 cirrhotic patients with mild-to-moderate HE, L-carnitine 2 g twice daily for 60 days improved mental status and ammonia versus baseline.
200.SupplementDEX Database: Hepatic encephalopathy — Effect of L-carnitine upon ammonia tolerance test in cirrhotic patients1990
In cirrhotic patients, L-carnitine before an ammonium challenge test improved psychomotor performance versus baseline in a controlled evaluation.
SupplementDEX Database · Hepatitis B
1 reference201.SupplementDEX Database: Hepatitis B — Efficacy and safety of entecavir plus carnitine complex (GODEX®) compared to entecavir monotherapy in patient with ALT elevated chronic hepatitis B: randomized, multicenter open-label trials. The GOAL study2013
In 130 chronic hepatitis B patients, entecavir plus carnitine complex improved liver enzymes and fatigue versus entecavir alone over 12 months.
SupplementDEX Database · Hepatitis C
3 references202.SupplementDEX Database: Hepatitis C — L-carnitine supplementation improves hematological pattern in patients affected by HCV treated with Peg interferon-α 2b plus ribavirin2011
In 35 chronic hepatitis C patients on IFN plus ribavirin, L-carnitine reduced anemia and dose reductions versus standard therapy over 12 months.
203.SupplementDEX Database: Hepatitis C — L-carnitine treatment reduces steatosis in patients with chronic hepatitis C treated with alpha-interferon and ribavirin2008
In 70 chronic hepatitis C patients, L-carnitine 2 g/day for 12 months reduced hepatic steatosis versus IFN/ribavirin alone during antiviral therapy.
204.SupplementDEX Database: Hepatitis C — L-carnitine decreases severity and type of fatigue induced by interferon-alpha in the treatment of patients with hepatitis C2003
In 50 HCV patients on interferon, L-carnitine 2 g/day for 1 year reduced fatigue severity versus standard therapy alone.
SupplementDEX Database · Hyperthyroidism
1 reference205.SupplementDEX Database: Hyperthyroidism — Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial2001
In 50 hyperthyroid patients, L-carnitine 2–4 g/day for 6 months improved symptoms and reduced biochemical hyperthyroidism markers versus baseline.
SupplementDEX Database · Hypothyroidism
1 reference206.SupplementDEX Database: Hypothyroidism — L-carnitine supplementation for the management of fatigue in patients with hypothyroidism on levothyroxine treatment: a randomized, double-blind, placebo-controlled trial2016
In 30 hypothyroid patients on levothyroxine with persistent fatigue, L-carnitine 1,980 mg/day for 12 weeks improved fatigue scores versus baseline.
SupplementDEX Database · Liver health
1 reference207.SupplementDEX Database: Liver health — Effects of oral Lcarnitine supplementation on liver enzymes in pediatric acute lymphoblastic leukemia patients in the maintenance phase of treatment: a randomized clinical trial study2025
In pediatric acute lymphoblastic leukemia, oral L-carnitine 50 mg/kg for 2 months reduced chemotherapy-related liver enzyme elevations versus control.
SupplementDEX Database · Low birth weight
10 references208.SupplementDEX Database: Low birth weight — L-carnitine-supplemented parenteral nutrition improves fat metabolism but fails to support compensatory growth in premature Korean infants2010
In 13 neonates, L-carnitine-supplemented parenteral nutrition improved fat metabolism markers but did not improve weight gain versus standard PN.
209.SupplementDEX Database: Low birth weight — Lack of effect of L-carnitine supplementation on weight gain in very preterm infants2005
In 63 very preterm infants, L-carnitine 16 mL/day did not improve weight gain versus control despite low carnitine status at enrollment.
210.SupplementDEX Database: Low birth weight — Primary and secondary alterations of neonatal carnitine metabolism1999
A review describes primary and secondary neonatal carnitine metabolism disorders and the role of carnitine in fatty acid oxidation and coenzyme A homeostasis.
211.SupplementDEX Database: Low birth weight — Randomised controlled trial of L-carnitine as a nutritional supplement in preterm infants1998
In preterm infants, L-carnitine 25 mg/kg/day did not significantly improve growth or reduce hypoglycemia versus control in a randomized trial.
212.SupplementDEX Database: Low birth weight — Effects of parenteral L-carnitine supplementation on fat metabolism and nutrition in premature neonates1995
In 43 very low birth weight infants, parenteral L-carnitine improved fat metabolism and carnitine concentrations but did not clearly improve nutritional outcomes versus control.
213.SupplementDEX Database: Low birth weight — Effect of intravenous L-carnitine on growth parameters and fat metabolism during parenteral nutrition in neonates1990
In 23 neonates on parenteral nutrition, IV L-carnitine 0.5 g/kg improved fatty acid oxidation markers but did not significantly improve growth versus control.
214.SupplementDEX Database: Low birth weight — Carnitine and total parenteral nutrition of the neonate1990
A review discusses carnitine requirements during neonatal total parenteral nutrition and the role of carnitine in newborn fat metabolism.
215.SupplementDEX Database: Low birth weight — Oral L-carnitine supplementation in low-birth-weight newborns: a study on neonates requiring combined parenteral and enteral nutrition1986
In 10 premature infants, oral L-carnitine supplementation altered plasma ketone bodies and triglycerides during combined enteral and parenteral feeding versus control.
216.SupplementDEX Database: Low birth weight — An evaluation of orally supplemented L-carnitine in premature infants receiving Intralipid 20%1983
In premature infants receiving Intralipid, oral L-carnitine did not clearly prevent carnitine deficiency or improve lipid tolerance versus unsupplemented control.
217.SupplementDEX Database: Low birth weight — Carnitine deficiency in premature infants receiving total parenteral nutrition: effect of L-carnitine supplementation1983
In premature infants on total parenteral nutrition, carnitine 10 mg/kg did not significantly improve fat tolerance or correct carnitine deficiency versus control in a randomized trial.
SupplementDEX Database · Migraine
3 references218.SupplementDEX Database: Migraine — L-carnitine versus Propranolol for pediatric migraine prophylaxis2021
In 56 children with episodic migraine, L-carnitine 50 mg/kg/day and propranolol 1 mg/kg/day both significantly reduced migraine frequency and severity over 12 weeks, with no significant difference between treatments.
219.SupplementDEX Database: Migraine — Acetyl-l-carnitine versus placebo for migraine prophylaxis: A randomized, triple-blind, crossover study2015
In 72 adults with episodic migraine, a 12-week crossover trial found no significant difference between acetyl-L-carnitine 3 g/day and placebo for moderate/severe headache days (3.0 vs 3.1 per month).
220.SupplementDEX Database: Migraine — The effects of magnesium, L-carnitine, and concurrent magnesium-L-carnitine supplementation in migraine prophylaxis2012
In 133 migraine patients, 12 weeks of magnesium oxide 500 mg/day, L-carnitine 500 mg/day, or combined supplementation all significantly reduced migraine frequency, duration, and severity versus control.
SupplementDEX Database · Multiple sclerosis
2 references221.SupplementDEX Database: Multiple sclerosis — Levocarnitine administration in multiple sclerosis patients with immunosuppressive therapy-induced fatigue2006
In MS patients with low plasma carnitine, oral levocarnitine 3–6 g/day normalized carnitine levels and reduced fatigue intensity in 63% of those on immunosuppressive therapy, especially with cyclophosphamide or interferon beta.
222.SupplementDEX Database: Multiple sclerosis — Comparison of the effects of acetyl L-carnitine and amantadine for the treatment of fatigue in multiple sclerosis: results of a pilot, randomised, double-blind, crossover trial2004
In 36 MS patients, acetyl-L-carnitine 1 g twice daily for 3 months was better tolerated and more effective than amantadine for reducing fatigue severity (p = 0.039).
SupplementDEX Database · Muscle mass & strength
2 references223.SupplementDEX Database: Muscle mass & strength — Effects of nine weeks L-Carnitine supplementation on exercise performance, anaerobic power, and exercise-induced oxidative stress in resistance-trained males2018
In 23 resistance-trained men, 9 weeks of L-carnitine 2 g/day increased bench press volume and peak power and reduced post-exercise blood lactate and oxidative stress markers versus placebo.
224.SupplementDEX Database: Muscle mass & strength — l-Carnitine Supplementation in Older Women. A Pilot Study on Aging Skeletal Muscle Mass and Function2018
In women aged 65–70, 24 weeks of L-carnitine-L-tartrate 1,500 mg/day raised plasma carnitine but did not change skeletal muscle strength, inflammatory markers, or IGF-1 versus placebo.
SupplementDEX Database · Myocardial infarction
10 references225.SupplementDEX Database: Myocardial infarction — Effective dosing of L-carnitine in the secondary prevention of cardiovascular disease: a systematic review and meta-analysis2014
A meta-analysis of 5 RCTs (3,108 patients) found L-carnitine after acute MI reduced all-cause mortality, with no significant dose differences between 2, 3, 4, and 6 g/day for mortality, heart failure, or reinfarction.
226.SupplementDEX Database: Myocardial infarction — L-carnitine in the secondary prevention of cardiovascular disease: systematic review and meta-analysis2013
A meta-analysis of 13 controlled trials (3,629 patients) found L-carnitine after acute MI reduced all-cause mortality by 27%, ventricular arrhythmias by 65%, and angina by 40% versus placebo.
227.SupplementDEX Database: Myocardial infarction — Metabolic treatment with L-carnitine in acute anterior ST segment elevation myocardial infarction. A randomized controlled trial2006
In the CEDIM 2 trial of 2,330 patients with anterior STEMI, L-carnitine reduced 5-day mortality (HR 0.61) but did not significantly reduce the 6-month composite of death and heart failure.
228.SupplementDEX Database: Myocardial infarction — Does left ventricular function improve with L-carnitine after acute myocardial infarction?1999
In 60 patients with acute anterior MI, 6 g/day IV L-carnitine for 7 days then 3 g/day oral for 3 months did not significantly improve left ventricular ejection fraction or end-systolic/diastolic volumes versus placebo.
229.SupplementDEX Database: Myocardial infarction — A randomised, double-blind, placebo-controlled trial of L-carnitine in suspected acute myocardial infarction1996
In 101 patients with suspected acute MI, oral L-carnitine 2 g/day for 28 days reduced infarct size, angina (17.6% vs 36.0%), heart failure (23.4% vs 36.0%), and total cardiac events (15.6% vs 26.0%) versus placebo.
230.SupplementDEX Database: Myocardial infarction — Controlled study on L-carnitine therapeutic efficacy in post-infarction1996
In 160 post-MI patients, oral L-carnitine 4 g/day for 12 months reduced angina, improved lipid profile, and lowered mortality to 1.2% versus 12.5% in controls.
232.SupplementDEX Database: Myocardial infarction — Effects of L-carnitine administration on left ventricular remodeling after acute anterior myocardial infarction: the L-Carnitine Ecocardiografia Digitalizzata Infarto Miocardico (CEDIM) Trial1995
In the CEDIM trial of 472 post-MI patients, L-carnitine 9 g/day IV then 6 g/day oral for 12 months significantly attenuated left ventricular dilation; death plus heart failure was 6% vs 9.6% with placebo.
233.SupplementDEX Database: Myocardial infarction — [Anti-arrhythmia treatment using L-carnitine in acute myocardial infarct]1992
In 20 acute MI patients, high-dose IV L-carnitine reduced high-grade ventricular premature beats on day 2 (4/12 vs 7/8 with placebo; p = 0.028), though 24-hour Holter differences were not significant.
234.SupplementDEX Database: Myocardial infarction — High doses of L-carnitine in acute myocardial infarction: metabolic and antiarrhythmic effects1989
In 56 acute MI patients, high-dose IV L-carnitine (100 mg/kg every 12 h) was studied for effects on urinary acylcarnitine excretion and early ventricular arrhythmias during the first 48 hours post-infarction.
231.The effect of L-carnitine in the infarct size in one-month post-myocardial infarction cases.. See external sourceExternal source
SupplementDEX Database · Narcolepsy
1 reference235.SupplementDEX Database: Narcolepsy — Effects of oral L-carnitine administration in narcolepsy patients: a randomized, double-blind, cross-over and placebo-controlled trial2013
In 28 narcolepsy patients, oral L-carnitine 510 mg/day for an unspecified duration significantly reduced excessive daytime sleepiness and increased serum acylcarnitine versus placebo.
SupplementDEX Database · Neonatal apnea
1 reference236.SupplementDEX Database: Neonatal apnea — Role of L-carnitine in apnea of prematurity: a randomized, controlled trial2002
In 44 preterm infants, carnitine supplementation 30 mg/kg/day did not reduce apnea of prematurity, ventilator days, or need for supplemental oxygen compared with placebo.
237.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Efficacy and safety of carnitine supplementation on NAFLD: a systematic review and meta-analysis2023
A meta-analysis found L-carnitine supplementation significantly reduced AST and ALT in NAFLD patients and lowered triglycerides, with greater liver enzyme reductions in adults than younger patients.
238.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Impact of L-Carnitine Supplementation on Liver Enzyme Normalization in Patients with Chronic Liver Disease: A Meta-Analysis of Randomized Trials2022
A meta-analysis of 14 RCTs (1,217 patients) found carnitine-orotate significantly increased ALT normalization rates (OR 4.61) and lowered serum ALT and AST in chronic liver disease.
239.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Effect of L-carnitine supplementation on children and adolescents with nonalcoholic fatty liver disease (NAFLD): a randomized, triple-blind, placebo-controlled clinical trial2021
In 55 children with NAFLD, 3 months of L-carnitine 50 mg/kg/day did not significantly improve AST, ALT, or liver ultrasound grading versus placebo, though within-group enzyme reductions occurred in both arms.
240.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Effect of L-carnitine supplementation on lipid profiles of patients with liver disease: a systematic review and meta-analysis2020
A meta-analysis found L-carnitine supplementation significantly reduced total cholesterol and triglycerides in liver disease patients, with no effect on HDL or LDL; benefits were greater with ≥24-week duration.
242.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Data from a randomized and controlled trial of L-Carnitine prescription for the treatment for Non-Alcoholic Fatty Liver Disease2014
In 80 NAFLD patients, L-carnitine 500 mg twice daily for 24 weeks significantly reduced ALT and improved fatty liver sonographic grading versus control.
243.SupplementDEX Database: Nonalcoholic fatty liver disease (NAFLD) — Effects of carnitine on peripheral blood mitochondrial DNA copy number and liver function in non-alcoholic fatty liver disease2010
In 45 NAFLD patients, 3 months of carnitine complex reduced ALT, AST, and bilirubin and increased peripheral blood mitochondrial DNA copy number versus control.
241.Evaluation of L-Carnitine Efficacy in the Treatment of Non-Alcoholic Fatty Liver Disease among Diabetic Patients: A Randomized Double Blind Pilot Study. See external sourceExternal source
244.SupplementDEX Database: Nonalcoholic steatohepatitis (NASH) — The efficacy of L-carnitine in patients with nonalcoholic steatohepatitis and concomitant obesity2023
In 90 obese patients with NASH, 90 days of L-carnitine plus simvastatin and diet significantly reduced cholesterol, triglycerides, LDL, atherogenic index, and insulin resistance versus standard therapy alone.
245.SupplementDEX Database: Nonalcoholic steatohepatitis (NASH) — Effect of L-carnitine supplementation on lipid accumulation product and cardiovascular indices in women with overweight/obesity who have knee osteoarthritis: a randomized controlled trial2022
In 76 overweight women with knee osteoarthritis, 12 weeks of L-carnitine 1,000 mg/day significantly reduced lipid accumulation product (−11.05 vs −5.82) but did not improve other cardiovascular risk indices versus placebo.
246.SupplementDEX Database: Nonalcoholic steatohepatitis (NASH) — Effects of l-carnitine supplementation on weight loss and body composition: A systematic review and meta-analysis of 37 randomized controlled clinical trials with dose-response analysis2020
A meta-analysis of 37 RCTs (2,292 participants) found L-carnitine supplementation modestly reduced body weight (−1.21 kg), BMI (−0.40), and fat mass (−2.08 kg), with maximum effect at ~2 g/day.
247.SupplementDEX Database: Nonalcoholic steatohepatitis (NASH) — Beneficial effects of l-carnitine supplementation for weight management in overweight and obese adults: An updated systematic review and dose-response meta-analysis of randomized controlled trials2020
A meta-analysis of 43 RCTs found L-carnitine significantly reduced body weight (−1.13 kg), BMI (−0.36), and fat mass (−1.16 kg), with greater effects in overweight/obese adults and when combined with lifestyle modifications.
248.SupplementDEX Database: Nonalcoholic steatohepatitis (NASH) — L-carnitine supplementation to diet: a new tool in treatment of nonalcoholic steatohepatitis--a randomized and controlled clinical trial2010
In NASH patients, L-carnitine 2 g/day for 24 weeks significantly improved liver enzymes, lipid profile, glucose, HOMA-IR, inflammatory markers, and histological scores versus diet alone.
249.SupplementDEX Database: Nonalcoholic steatohepatitis (NASH) — L-Carnitine supplementation combined with aerobic training does not promote weight loss in moderately obese women2000
In 36 moderately obese premenopausal women, 8 weeks of L-carnitine 4 g/day plus aerobic training did not reduce total body mass or fat mass compared with exercise plus placebo.
SupplementDEX Database · Obesity
2 references250.SupplementDEX Database: Obesity — Modulatory Effects of Multi-species/Multi-strain Synbiotic and L-carnitine Concomitant Supplementation on Atherogenic-Indices, Body Composition, Visceral Obesity, and Appetite in Metabolically Healthy Women with Obesity: A Double-Blind Randomized Controlled Clinical Trial2025
In 46 obese women, 8 weeks of L-carnitine plus synbiotic co-supplementation significantly reduced atherogenic indices, fat mass, visceral adiposity, and appetite scores more than L-carnitine alone.
251.SupplementDEX Database: Obesity — The effect of (L-)carnitine on weight loss in adults: a systematic review and meta-analysis of randomized controlled trials2016
A meta-analysis of 9 RCTs (911 adults) found L-carnitine supplementation reduced body weight by 1.33 kg and BMI by 0.47 kg/m² versus control, with diminishing effects over longer durations.
SupplementDEX Database · Osteoarthritis
3 references252.SupplementDEX Database: Osteoarthritis — The effect of L-Carnitine supplementation on clinical symptoms, C-reactive protein and malondialdehyde in obese women with knee osteoarthritis: a double blind randomized controlled trial2021
In 76 obese women with knee osteoarthritis on a low-calorie diet, 12 weeks of L-carnitine 1 g/day improved BMI (−1.21 vs −0.79) but did not significantly improve WOMAC scores, CRP, or MDA versus placebo.
253.SupplementDEX Database: Osteoarthritis — Effects of l-Carnitine Supplementation on Serum Inflammatory Factors and Matrix Metalloproteinase Enzymes in Females with Knee Osteoarthritis: A Randomized, Double-Blind, Placebo-Controlled Pilot Study2016
In 69 women with knee osteoarthritis, 8 weeks of L-carnitine 750 mg/day significantly reduced serum IL-1β and MMP-1 and lowered VAS pain scores by 52.7% versus 21.8% with placebo.
254.Effect of l-carnitine supplementation on clinical symptoms in women with osteoarthritis of the knee: A randomized, double-blind, placebo-controlled trial. See external sourceExternal source
255.SupplementDEX Database: Persistent depressive disorder (PDD) — L-Acetylcarnitine in dysthymic disorder in elderly patients: a double-blind, multicenter, controlled randomized study vs. fluoxetine2013
A multicenter, double-blind, randomized trial in 80 elderly patients with Dysthymic Disorder compared L-acetylcarnitine (3 g/day) with fluoxetine (20 mg/day) over 7 weeks, finding equivalent improvements in depression and anxiety scales, but a faster onset of response with acetylcarnitine. URL: https://pubmed.ncbi.nlm.nih.gov/23428336/ Year: 2013 Verified Source: PubMed
SupplementDEX Database · Renal anemia
1 reference256.SupplementDEX Database: Renal anemia — Effects of L-carnitine supplementation on renal anemia in poor responders to erythropoietin2001
In 14 hemodialysis patients with erythropoietin-refractory anemia, 500 mg/day oral L-carnitine for 3 months raised hematocrit in 36% and significantly increased mean hematocrit versus baseline.
SupplementDEX Database · Rett syndrome
2 references257.SupplementDEX Database: Rett syndrome — Medium-term open label trial of L-carnitine in Rett syndrome2001
In an open-label trial of 21 Rett syndrome females versus 62 controls over 6 months, L-carnitine significantly improved sleep efficiency, energy level, and communication skills.
258.SupplementDEX Database: Rett syndrome — Rett syndrome: randomized controlled trial of L-carnitine1999
In 35 Rett syndrome subjects in an 8-week crossover RCT, L-carnitine did not significantly improve parent- or caregiver-rated outcomes versus placebo.
SupplementDEX Database · Sarcopenia
1 reference259.SupplementDEX Database: Sarcopenia — L-Carnitine Combined with Leucine Supplementation Does Not Improve the Effectiveness of Progressive Resistance Training in Healthy Aged Women2022
In 37 women aged 60–75 completing 24 weeks of resistance training, L-carnitine plus leucine did not improve muscle strength or hypertrophy beyond training alone.
SupplementDEX Database · Sepsis
2 references260.SupplementDEX Database: Sepsis — The supplementation of L-carnitine in septic shock patients: Systematic review and meta-analysis2022
A meta-analysis of septic shock trials (275 participants) found insufficient evidence that L-carnitine reduces mortality versus placebo or usual care.
261.SupplementDEX Database: Sepsis — The Effect of L-Carnitine on Mortality Rate in Septic Patients: A Systematic Review and Meta-Analysis on Randomized Clinical Trials2020
A systematic review and meta-analysis found L-carnitine may reduce mortality in septic patients, but evidence remained inconclusive for 28-day and 1-year mortality endpoints.
SupplementDEX Database · Sexual dysfunction
1 reference262.SupplementDEX Database: Sexual dysfunction — Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging2004
An RCT in 120 men aged 60–74 found propionyl-L-carnitine plus acetyl-L-carnitine (2 g/day each) for 6 months improved erectile function and mood as well as testosterone, without raising prostate volume.
263.SupplementDEX Database: Severe acute malnutrition — Effects of L-Carnitine Supplementation on the Rate of Weight Gain and Biomarkers of Environmental Enteric Dysfunction in Children with Severe Acute Malnutrition: A Double-Blind Randomized Controlled Clinical Trial2024
A double-blind, placebo-controlled randomized clinical trial in Bangladeshi children with severe acute malnutrition (aged 9-24 months) showing that 15 days of L-carnitine (100 mg/kg/day) did notsignificantly increase the rate of weight gain or improve biomarkers of environmental enteric dysfunction compared to placebo.
264.SupplementDEX Database: Urinary tract infections — Preventive Effect of L-Carnitine on Scar Formation During Acute Pyelonephritis: A Randomized Placebo-Controlled Trial2020
In 65 children with acute pyelonephritis, L-carnitine plus antibiotics for 7 days did not significantly reduce renal scarring versus antibiotics alone.