L-carnitine B
Does not burn fat: the average effect is about 1–1.2 kg and is clinically insignificant
Citable fact
«L-carnitine» — evidence level B. Dosage: 2–3 g per day in weight studies; the effect is small, and the dose dependence is non-linear, with a maximum at about 2 g per day. Forms: L-carnitine tartrate, free carnitine. Source: PMID 32359762, permanent link to the source in the list below.
How it works
It transports long-chain fatty acids into mitochondria for oxidation. In people with a normal diet there is no carnitine deficiency, so the supplement does not increase the rate of fat oxidation.
Dosage and intake
2–3 g per day in weight studies; the effect is small, and the dose dependence is non-linear, with a maximum at about 2 g per day. Forms: L-carnitine tartrate, free carnitine.
With insulinogenic food or carbohydrates — this improves carnitine accumulation in muscle; to reduce soreness, take it several hours before exercise.
Forms
L-carnitine L-tartrate and free carnitine have been studied. Acetyl-L-carnitine has been studied mainly in neurology, not in sports.
What is confirmed
- Meta-analysis of 37 RCTs: weight reduction on average about 1–1.2 kg, clinically insignificant
- The dose dependence is non-linear: the maximum effect occurs at about 2 g per day
- A possible small reduction in soreness and markers of muscle damage
Adverse effects and limitations
- Nausea, diarrhea and a “fishy” body odor at doses above 3 g
- There are reports of erosive gastritis with long-term use of large doses
- Does not replace a calorie deficit, without which fat is not lost
Interactions
- Pivaloyl carnitine and warfarin: possible enhancement of the effect, monitoring required
- In hypothyroidism and with thyroid hormone use, their effect may increase
Who must not use it
- Under 18 years: Not recommended.
- Pregnancy and lactation: Not recommended without a doctor's prescription.
- chronic kidney disease
- hypothyroidism
- warfarin use
- epilepsy
Sources
- 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 analysis · Talenezhad N, Mohammadi M, Ramezani-Jolfaie N · Clinical nutrition ESPEN, 2020 · PMID 32359762
- International society of sports nutrition position stand: diets and body composition · Aragon AA, Schoenfeld BJ, Wildman R · Journal of the International Society of Sports Nutrition, 2017 · PMID 28630601
- The Top 5 Can't-Miss Sport Supplements · Antonio J, Pereira F, Curtis J · Nutrients, 2024 · PMID 39408214
See also
Open in the app
This page holds reference data with links to studies. In the app you can calculate calories and macros for your goal, build a personal supplement stack and review weekly training volume.