Weak evidence · Fat loss
L-carnitine
Sold for fat transport and fat loss
Weak evidence
Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
Meta-analyses of randomised studies found on average about 1.1 to 1.3 kg more weight loss, mainly in people with overweight, and the effect shrank the longer the intake lasted. Oral carnitine barely raises the level in your muscles, unless you take it for months with a lot of carbohydrates (a 24-week trial with 2 g of carnitine and 80 g of carbohydrate, twice daily).
- Dosage
- No recommended dose for healthy athletes
- Timing
- —
- Approx. price
- €12–25 per month
Watch out
Gut bacteria convert carnitine into TMAO, a substance associated with cardiovascular disease; its clinical importance is uncertain. While that is unclear, long-term use is not advisable.
Frequently asked questions about supplements
How much L-carnitine per day?
No recommended dose for healthy athletes
Does L-carnitine really work?
Weak evidence. Mostly small studies, animal trials or conflicting results. Not worth your money as a foundation.
What does L-carnitine cost?
€12–25 per month
Basics first, then the tub
Supplements are called supplements because they add to something. Sleep, a protein intake that hits your protein calculator , a programme where you lift progressively heavier and enough food together do a hundred times more than the best-researched item on this list. Once those are in place, creatine, caffeine and vitamin D in winter are the three you can spend money on with a clear conscience — for less than ten euros a month combined.
Sources
- Pooyandjoo M et al. (2016). The effect of (L-)carnitine on weight loss in adults: a systematic review and meta-analysis of randomized controlled trials. Obes Rev. (meta-analysis)
- Wall BT et al. (2011). Chronic oral ingestion of L-carnitine and carbohydrate increases muscle carnitine content and alters muscle fuel metabolism during exercise in humans. J Physiol 589:963-973. (randomized trial)
More supplements in this category
Last updated: October 2026
This page summarises scientific research and is not medical advice. If you take medication, are pregnant or have a liver, kidney or thyroid condition, discuss supplements with your doctor or pharmacist — even the innocent-looking ones.
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