People mainly take L-Carnitine for energy, weight loss, focus. Based on 59 first-hand reports and 170 meta-analyses & systematic reviews in the medical literature. Ranked #351 of 1,974 overall.
Of reports that state an outcome, 67% are positive.
Of the people who reported each effect, the share who said it got better.
Systematic reviews and meta-analyses from PubMed, with their published conclusions.
3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.
Conclusion: l-carnitine supplementation provides a modest reducing effect on body weight, BMI and fat mass, especially among adults with overweight/obesity.
PubMed 32359762 ↗Conclusion: Using multiple-treatments meta-analysis of the drugs and non-pharmacotherapy options seem to be insightful areas for research. © 2016 World Obesity.
PubMed 27335245 ↗Conclusion: The overall analysis including all trials showed that supplements provided moderate and clinically meaningful treatment effects on pain and function in patients with hand, hip or knee osteoarthritis at short term, although the quality of evidence was very low. Some supplements with a limited number of studies and participants suggested large treatment effects, while widely used supplements such as glucosamine and chondroitin were either ineffective or showed small and arguably clinically unimportant treatment effects. Supplements had no clinically important effects on pain and function at medi
PubMed 29018060 ↗Conclusion: Anthropometric indexes were not changed following l-carnitine supplementation among patients' undergoing hemodialysis. Our study revealed that l-carnitine supplementation might have a positive effects in achieving an improved body weight and BMI especially in overweight and obese subjects.
PubMed 31743774 ↗As stated by users — not a recommendation. Follow the label or your doctor.
How often each side effect came up across all reports.
Verbatim quotes, shortened only — each links to the original discussion.
“I would go with Acetyl-L-Carnitine (ALCAR) over l-carnitine.”
“Kaged Muscle L-carnitine - 2g per day, for cardiovascular health and to enhance creatine absorption in muscle tissues”
“I've added L-Carnitate, Vitamin A, C and E to the mix.”
“on TRT, taking creatine, injecting L-Carnitine, multivitamins”
“Ya L-carn will actually improve lipolysis (the body's ability to break down stored fat)”
User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 2, 2026. How we rate