PeptideCompareL-Carnitine — EU research guide.
L-Carnitine is a naturally occurring amino acid derivative essential for the transport of long-chain fatty acids into mitochondria for beta-oxidation. It is one of the most extensively studied metabolic compounds in human nutrition and sports science.
What is L-Carnitine?
L-Carnitine is synthesised in the liver and kidneys from lysine and methionine, with vitamin C as a cofactor. It forms acylcarnitine esters with fatty acyl-CoA, allowing transport across the inner mitochondrial membrane via the carnitine shuttle. Without adequate carnitine, long-chain fatty acid oxidation is impaired. Injectable forms are used in clinical medicine for primary carnitine deficiency.
What does the research show?
Oral supplementation evidence for performance enhancement in healthy individuals is mixed; benefits are most clear in carnitine-deficient states (vegetarians, renal disease patients, elderly). Injectable L-carnitine shows more reliable bioavailability. Meta-analyses suggest modest improvements in fat oxidation, insulin sensitivity and recovery in specific populations. IV carnitine is used clinically for haemodialysis-related carnitine deficiency in the EU.
EU legal status
L-Carnitine is a legal food supplement in the EU (oral). Injectable research-grade L-carnitine is sold for laboratory and veterinary research. Injectable clinical preparations require prescription.
Molecular information
Pharmacokinetics
Potency retained over time
Each line is one storage condition: it starts at 100% and falls as potency is lost. Above the dashed 80% line the material is considered reliable — hover for exact values.
⚠ A structural estimate, derived from each compound's sequence length, cyclisation and oxidation-, deamidation- and light-sensitive residues. Indicative only — not lab-measured per batch.
L-Carnitine across EU suppliers
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