L-carnitine moves fats into mitochondria. The body makes it, and red meat is the main food source. It is sold for exercise recovery and fat burning.
Calculator Official intake Study doses Best form Safety Sources
This is not an essential nutrient, so there is no official daily intake. Only study doses are shown.
These are doses tested in research, not personal advice. Some exceed the upper limit because they were short courses or given under medical care.
1-3 g a day
A meta-analysis of 7 trials found less muscle soreness and lower muscle damage markers the day after hard exercise. A systematic review found chronic doses of 1 to 3 g a day; effects on performance were mixed.
2-3 g a day
A meta-analysis of 13 trials (3,629 patients) after a heart attack linked L-carnitine to 27% lower death rates and fewer arrhythmias and angina episodes. A dosing analysis found no extra benefit above about 3 g a day. Many trials were old; only with your cardiologist.
DiNicolantonio JJ et al. 2013 · Shang R et al. 2014
Other findings
Gut bacteria turn carnitine into TMAO, which sped up hardening of the arteries in mice. In people, high blood carnitine predicted heart events only when TMAO was also high. Not proof of harm from supplements, but a reason for caution.
No best form
Why: Exercise studies used L-carnitine or L-carnitine L-tartrate. Count by carnitine content: tartrate is about 68% carnitine.
L-carnitine L-tartrate is about 68% carnitine by its formula. Acetyl-L-carnitine is studied mainly for brain health and is not covered here.
Red meat (by far the most), dairy, fish, poultry.
Ask your doctor if you take blood thinners or thyroid medicine.
Doses around 3 g a day can cause a fishy body odour and stomach upset.
Pregnant, breastfeeding, on medication, or managing a health condition? Check with a doctor or pharmacist before starting a supplement.
Values checked: November 12, 2026.
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