home / compounds / L-Carnitine
L-Carnitine
A well-studied nutrient compound, not a peptide.
What it is
An amino acid derivative essential to transporting fatty acids into mitochondria for oxidation.
What it does
Supports fatty-acid transport and energy metabolism; also used clinically in carnitine deficiency states.
Does it work?
Extensively studied as an oral supplement with modest and context-dependent effects. Clinical deficiency states are a genuine indication; performance and fat-loss claims in healthy people are much weaker.
Claims vs data
Each marketing claim, tagged by what the evidence actually supports.
| Corrects clinical carnitine deficiency | supported |
| Modest, context-dependent performance effects | partially true |
| Burns fat in healthy adults | weak evidence |
Reference figures
Quoted from published reference material. These are not Peptuity recommendations.
The evidence, counted
Live counts from Europe PMC and ClinicalTrials.gov.
23,553 publications indexed, including 735 randomised controlled trials. 356 interventional studies registered. This is a well-tested compound.
query: "L-Carnitine" · checked 2026-08-07
Most-cited literature
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Intestinal microbiota metabolism of L-carnitine, a nutrient in red meat, promotes atherosclerosis
Koeth RA, Wang Z, Levison BS, Buffa JA, Org E, Org E, Sheehy BT, Britt · Nat Med 2013 · 3315 citations
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Multi-omics of the gut microbial ecosystem in inflammatory bowel diseases
Lloyd-Price J, Arze C, Ananthakrishnan AN, Schirmer M, Avila-Pacheco J · Nature 2019 · 2431 citations
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Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update
Sarin SK, Kumar M, Lau GK, Abbas Z, Chan HL, Chen CJ, Chen DS, Chen HL · Hepatol Int 2016 · 1928 citations
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Integrating taxonomic, functional, and strain-level profiling of diverse microbial communities with bioBakery 3
Beghini F, McIver LJ, Blanco-Míguez A, Dubois L, Asnicar F, Maharjan S · Elife 2021 · 1911 citations
Regulatory status
Formal, dated regulatory actions.
WADA — Prohibited List 2026
Permitted — but intravenous infusions above 100 ml per 12 h are prohibited in sport
Common questions
Is L-carnitine a peptide?
No — it is an amino acid derivative sold in the same catalogues. Its evidence base is oral supplementation, which is unusual for this list.
Does injecting it beat taking it orally?
Injection bypasses poor oral absorption, but the outcome evidence people cite comes overwhelmingly from oral studies. Better absorption of a modest effect is still a modest effect.
Will it burn fat on its own?
Trials in healthy adults show modest, context-dependent effects at best. It transports fatty acids; it does not create an energy deficit.