Amino acids & related
Carnitine
Names you may see: L-carnitine acetyl L carnitine L-carnitine tartrate ALCAR
The quick take
Carnitine helps transport long-chain fatty acids into mitochondria, where they can be used for energy.
A closer look
What forms will I see on a label?
Common labels include L-carnitine, L-carnitine L-tartrate and acetyl-L-carnitine. Their study contexts and amounts differ.
Why people use it
Marketed for fat metabolism, weight management and exercise recovery. Its role in transporting fatty acids does not mean taking extra automatically burns body fat.
These are common goals and marketing uses. The evidence section below explains what research supports.
What does the evidence tell us?
A role in fat metabolism does not mean supplemental carnitine automatically causes fat loss. Evidence depends on the population, form and outcome being studied.
What should I know before using it?
Supplemental carnitine can cause gastrointestinal discomfort and a fishy body odour. Review medicines and health conditions with a pharmacist.
Sources & further reading
NIH Office of Dietary Supplements ↗
Content reviewed: September 30, 2026
General educational information. Follow the product label and seek individual advice when needed.