L-carnitine
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Every diet
It is made by chemical synthesis or by fermentation.
No carbohydrate.
Safe in small amounts; may bother some people or raise blood sugar.
Rules by country
L-carnitine is sold as a nutrient and as a dietary supplement, and it is not on the list of permitted additives in the EU, the United States or Canada, so it carries neither an E-number nor an INS number. None of the three regulators evaluates it as an additive, and what governs it instead is the general law on food supplements and on vitamins and minerals.
What is it?
L-carnitine is a molecule the body makes from lysine and methionine and uses to move long-chain fatty acids into mitochondria, where they are burned for fuel. It is named from the Latin for meat, because it was first isolated from meat extracts in 1905, and red meat and dairy are the richest sources, with almost none in plants. The pink in raw meat comes from myoglobin rather than from carnitine, though carnitine concentrates in exactly the red muscle fibers that do long work.
Where it comes from: L-carnitine is made by chemical synthesis or by fermentation, and what goes on the label is usually L-carnitine L-tartrate, the form used in supplements because the tartrate salt is stable and dissolves easily.
Why it’s in food
- Transporting fat into mitochondria
- Endurance and recovery supplements
- Fat-loss supplement marketing
- Nutrient in preterm formula
- Senior nutrition supplements
Often found in
Also listed as: L-carnitine, Carnitine, L-carnitine tartrate, Levocarnitine, Carnitine L-tartrate
Health & gut impact
An omnivorous diet delivers on the order of 50 to 100 mg of carnitine a day, mostly from meat and dairy, while plants supply almost none. The liver and kidneys make roughly 100 mg a day from lysine and methionine, which is why strict vegetarians are the group most likely to notice a shortfall.
EFSA, dietary reference values for protein
The dose on the shelf matters more than the molecule. Labels run from 500 mg to 3 g a serving, and EFSA's work on L-carnitine described 3 g a day as producing mild stomach upset and a fishy body odor in short trials, while the hundreds of milligrams in a standard tablet did not.
EFSA Journal, scientific opinion on L-carnitine
Carnitine is highest in red and organ meat, and the committee that writes the US dietary guidelines puts red meat at about 26 ounces-equivalent a week for people who eat it. Most of the carnitine in a mixed diet arrives with those cuts rather than with milk or fish.
US Dietary Guidelines Advisory Committee, red meat
What can I use instead?
Ratio: Take 3 to 5 g a day, where carnitine tablets carry 500 mg to 3 g
Best for: Strength work, where the evidence is much stronger
Ratio: Two servings a day cover the intake of an omnivorous diet
Best for: Filling the gap without a supplement
Ratio: About 200 mg, which is two cups of brewed coffee
Best for: When the goal is alertness rather than fat metabolism
Related
More functional ingredients:
Common questions
Does L-carnitine burn fat?
It moves fat into the cells that burn it, which is a real job in the body. In people who do long endurance work it can help a little, and in everyone else the effect on body fat is small enough that EFSA did not support the weight-loss claim.
Why does my urine smell fishy after a supplement?
That is the most common side effect of L-carnitine, and it comes from breakdown products called trimethylamines. It is harmless, it shows up most at the higher doses of 2 g and above, and it gets stronger with fish, which brings its own trimethylamine along.
Do vegetarians need L-carnitine?
More than most people do. Plants contain almost no carnitine, so a strict vegetarian diet supplies a few milligrams a day where an omnivorous diet supplies 50 to 100 mg, and the body makes most of what it needs from lysine and methionine, so it is not an essential nutrient.
Is L-carnitine in red meat?
Red and organ meat are the richest sources in the diet, and the compound was first isolated from meat in 1905. The pink in raw meat comes from myoglobin rather than from carnitine, though carnitine does concentrate in exactly the muscle fibers that handle long, slow work.
Is L-carnitine safe?
Use in moderation (80/100). L-carnitine is sold as a nutrient and as a dietary supplement, and it is not on the list of permitted additives in the EU, the United States or Canada, so it carries neither an E-number nor an INS number. None of the three regulators evaluates it as an additive, and what governs it instead is the general law on food supplements and on vitamins and minerals.
Is L-carnitine vegan?
Yes. It is made by chemical synthesis or by fermentation.
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Scientific sources & regulatory citations
- EFSA, dietary reference values for protein
- EFSA Journal, scientific opinion on L-carnitine
- US Dietary Guidelines Advisory Committee, red meat
CAS 541-92-6