Carnitine

What carnitine is and what it does

Carnitine is not a vitamin and not a classic amino acid. Your body makes it in the liver and kidneys from lysine and methionine. Its job is transport: it moves long-chain fatty acids into the mitochondria, the small energy units inside your cells. Almost all of your carnitine sits in skeletal muscle. In food it comes mainly from red meat such as beef and lamb. Poultry and dairy contain much less, and plant foods almost none.

That explains who usually lands on this page: people who eat little or no meat, and people who train regularly and want a stimulant-free option next to their protein or creatine. Carnitine sits in our wider range of amino acids and derivatives, and it behaves differently from most of them.

The forms differ more than the labels show

Most products use carnitine bound to another molecule, because pure carnitine pulls in water and clumps. L-carnitine L-tartrate is the form used in most exercise research. Acetyl-L-carnitine carries an extra acetyl group and is the form you see in mind-focused formulas; we keep a separate range of acetyl-L-carnitine products. Propionyl-L-carnitine and fumarate appear far less often. One rule applies everywhere: only the L-form is active in the body, the D-form is not.

Read the label for the amount of carnitine itself, not only the weight of the salt. Roughly 3,000 mg of L-carnitine L-tartrate delivers about 2,000 mg of carnitine. Format is a practical choice, not a quality one: powder costs least per gram and mixes into a drink, capsules travel well, liquid shots are convenient but usually cost more per gram.

How we choose the carnitine in this range

Three things decide whether a carnitine product goes live here: the form, the dose per serving, and whether the combination makes sense. We prefer clearly labelled single forms, L-tartrate for training use and acetyl-L-carnitine where focus is the goal, over blends that hide a small amount of carnitine behind a long ingredient list. We also want the elemental carnitine amount stated, not just the salt weight. We buy directly from the brands, our compliance team checks every label before it goes online, and we test products ourselves alongside independent lab spot-checks. You can read how we select brands.

What to expect, and what we will not promise

UK and European rules only allow health claims that have been approved. For carnitine, none have been. EFSA assessed proposed claims about lipid metabolism, endurance and recovery after exercise and did not accept them. So we describe what carnitine does in the body and leave the promises out. That is the honest version, and it still leaves a clear use case: a stimulant-free addition to a training or dietary routine, often taken next to the sports nutrition you already use.

• Vegan and vegetarian eaters: intake from food is low, so a modest daily dose is the usual choice.
• Strength and endurance training: L-carnitine L-tartrate, taken with a meal that contains carbohydrate.
• Sensitive to stimulants: carnitine contains no caffeine.

Give it a few weeks of consistent use rather than judging it after two days. Many UK labels state that carnitine is not suitable during pregnancy or breastfeeding, and if you take prescription medication it is sensible to check with your GP first.