L-Carnitine
Research reviewed: Up until 03/2026
L-Carnitine is a dietary supplement with 14 published peer-reviewed studies involving 3,200 participants, researched for Weight Management, Exercise Performance, Cardiovascular Health.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Weight Management
StrongExercise Performance
StrongCardiovascular Health
StrongResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Weight Management
To determine the effect of L-carnitine supplementation on weight loss in adults
Study Type
Systematic review and meta-analysis
Purpose
To determine the effect of L-carnitine supplementation on weight loss in adults
Dose
Various
Participants
Multiple RCTs pooled
Duration
Various
Results
L-carnitine supplementation produced significantly greater weight loss (MD -1.33 kg) vs placebo.
How They Measured It
Body weight, BMI, body composition
To examine effects of L-carnitine supplementation on weight loss and body composition across 37 RCTs
Study Type
Systematic review and meta-analysis
Purpose
To examine effects of L-carnitine supplementation on weight loss and body composition across 37 RCTs
Dose
Various
Participants
2198 participants across 37 RCTs
Duration
Various
Results
L-carnitine significantly reduced body weight and body fat; dose-response relationship identified.
How They Measured It
Body weight, fat mass, lean mass, BMI
To evaluate effects of L-carnitine on weight loss, glycaemic control, and cardiovascular risk in T2DM
Study Type
Systematic review and meta-analysis
Purpose
To evaluate effects of L-carnitine on weight loss, glycaemic control, and cardiovascular risk in T2DM
Dose
Various
Participants
2041 T2DM patients across 21 RCTs
Duration
Various
Results
L-carnitine significantly reduced BMI (MD -0.37 kg/m2) and improved insulin sensitivity in T2DM.
How They Measured It
Body weight, BMI, HbA1c, lipid profile
To examine L-carnitine supplementation effect on fat oxidation and energy expenditure
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To examine L-carnitine supplementation effect on fat oxidation and energy expenditure
Dose
2 g/day L-carnitine
Participants
26 overweight adults
Duration
12 weeks
Results
L-carnitine significantly increased fat oxidation rate and reduced RQ, indicating greater fat burning.
How They Measured It
Fat oxidation rate, energy expenditure, RQ
Exercise Performance
To investigate L-carnitine supplementation effect on muscle recovery after exercise
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To investigate L-carnitine supplementation effect on muscle recovery after exercise
Dose
2 g/day L-carnitine L-tartrate
Participants
15 male athletes
Duration
3 weeks
Results
L-carnitine supplementation significantly reduced muscle soreness and CK release post-exercise.
How They Measured It
Muscle soreness VAS, CK levels, hormone response
To assess L-carnitine effect on exercise capacity and fatigue in heart failure patients
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess L-carnitine effect on exercise capacity and fatigue in heart failure patients
Dose
3 g/day L-carnitine
Participants
79 stable heart failure patients
Duration
6 months
Results
Significant improvements in exercise capacity, NYHA class, and ejection fraction vs placebo.
How They Measured It
6-minute walk test, NYHA class, peak VO2
To assess L-carnitine supplementation on anaerobic performance and recovery in athletes
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess L-carnitine supplementation on anaerobic performance and recovery in athletes
Dose
3 g/day L-carnitine L-tartrate
Participants
20 trained athletes
Duration
3 weeks
Results
L-carnitine reduced exercise-induced oxidative stress and improved anaerobic performance capacity.
How They Measured It
Sprint performance, recovery markers, muscle damage
To evaluate L-carnitine supplementation on exercise performance and recovery across RCTs
Study Type
Systematic review and meta-analysis
Purpose
To evaluate L-carnitine supplementation on exercise performance and recovery across RCTs
Dose
Various
Participants
Multiple RCTs pooled
Duration
Various
Results
L-carnitine supplementation improved exercise performance, reduced fatigue, and enhanced recovery in athletes.
How They Measured It
VO2max, exercise capacity, fatigue markers
Cardiovascular Health
To evaluate L-carnitine on lipid profile and cardiovascular risk in type 2 diabetes
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate L-carnitine on lipid profile and cardiovascular risk in type 2 diabetes
Dose
2 g/day L-carnitine
Participants
100 T2DM patients
Duration
12 weeks
Results
L-carnitine significantly reduced LDL, triglycerides and lipoprotein(a); increased HDL vs placebo.
How They Measured It
Total cholesterol, LDL, HDL, triglycerides, lipoprotein(a)
To evaluate L-carnitine effect on mortality and cardiac outcomes after myocardial infarction
Study Type
Systematic review and meta-analysis
Purpose
To evaluate L-carnitine effect on mortality and cardiac outcomes after myocardial infarction
Dose
Various
Participants
Multiple trials pooled
Duration
Various
Results
L-carnitine associated with 27% reduction in all-cause mortality and significant cardiac improvements.
How They Measured It
All-cause mortality, ventricular arrhythmias, anginal symptoms
To evaluate L-carnitine supplementation in peripheral artery disease patients
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate L-carnitine supplementation in peripheral artery disease patients
Dose
2 g twice daily L-carnitine
Participants
155 peripheral artery disease patients
Duration
12 months
Results
Significant increases in pain-free and maximum walking distance vs placebo (p<0.001).
How They Measured It
Pain-free walking distance, ankle-brachial index
To assess L-carnitine effect on hypertension and arterial stiffness
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess L-carnitine effect on hypertension and arterial stiffness
Dose
2 g/day
Participants
80 hypertensive adults
Duration
24 weeks
Results
L-carnitine significantly reduced systolic blood pressure and improved endothelial function vs placebo.
How They Measured It
Blood pressure, aortic stiffness, endothelial function
To evaluate L-carnitine supplementation on male infertility and sperm quality
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate L-carnitine supplementation on male infertility and sperm quality
Dose
2 g/day L-carnitine + 1 g/day acetyl-L-carnitine
Participants
100 infertile men
Duration
6 months
Results
Significant improvements in total sperm motility and morphology vs placebo (p<0.01).
How They Measured It
Sperm motility, morphology, count
To assess L-carnitine supplementation on fatigue in chronic fatigue syndrome patients
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess L-carnitine supplementation on fatigue in chronic fatigue syndrome patients
Dose
3 g/day L-carnitine
Participants
30 CFS patients
Duration
8 weeks
Results
L-carnitine supplementation significantly reduced fatigue scores and improved functional status vs placebo.
How They Measured It
Fatigue severity scale, clinical outcomes
Frequently Asked Questions
Common questions about L-Carnitine research
There are currently 14 peer-reviewed studies on L-Carnitine (L-Carnitine), involving 3,200 total participants. Research covers Weight management, Exercise performance, Cardiovascular health. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (14 human studies), and reported outcomes.
L-Carnitine has been researched for: Weight management, Exercise performance, Cardiovascular health. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 14 out of 14 studies are human trials. Human trials carry more weight in our evidence scoring system.
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