L-Carnitine (levocarnitine) is the compound cells use to move long-chain fatty acids across the inner mitochondrial membrane so they can be burned by beta-oxidation.[1] PubChem lists it as C7H15NO3, 1...
Certificate of Analysis included with every order.
About L-Carnitine
L-Carnitine (levocarnitine) is the compound cells use to move long-chain fatty acids across the inner mitochondrial membrane so they can be burned by beta-oxidation.[1] PubChem lists it as C7H15NO3, 161.20 g/mol, CAS 541-15-1.[3] Pepitiva supplies L-Carnitine as a lyophilized powder (6000 mg vials, ≥99% purity) for in vitro and preclinical research.
Where carnitine comes from
The body synthesizes carnitine and also takes it from meat and dairy products. Cells accumulate it, and the kidneys retain it, through OCTN2, a high-affinity organic cation transporter specific for carnitine.[1] Carnitine is also one of the compounds grouped as lipotropes, alongside choline, betaine, myo-inositol and methionine.[7]
Approved medical use
Injectable levocarnitine is an FDA-approved prescription drug, first approved in this dosage form in 1992.[4] Primary carnitine deficiency, caused by defects in OCTN2, responds to carnitine treatment.[1] The research-grade powder sold here is not that drug product.
For research use only. Not for human consumption.
Mechanism of Action
The carnitine shuttle
Long-chain fatty acids are the most abundant fatty acids in the diet and in body stores, and more than 15 enzymes take part in their mitochondrial oxidation. Carnitine is the carrier in this shuttle: the fatty acid travels into the mitochondrion as an acylcarnitine, and when the pathway is blocked, long-chain acylcarnitines accumulate.[1][2] Fatty acid oxidation is an essential energy source during prolonged fasting and submaximal exercise.[2]
What happens when it fails
Primary carnitine deficiency: defects in the OCTN2 transporter (gene SLC22A5) lower intracellular carnitine and increase its loss in urine. Patients can present early in life with hypoketotic hypoglycemia and hepatic encephalopathy, or later with skeletal and cardiac myopathy.[1]
Long-chain fatty acid oxidation disorders: symptoms range from hypoketotic hypoglycemia and liver dysfunction to rhabdomyolysis and cardiomyopathy, and they typically appear during fasting, illness or endurance exercise.[2]
Defects in carnitine biosynthesis, by contrast, do not routinely lower plasma carnitine.[1]
Research Applications
Human research background
Weight loss (2016): a meta-analysis of nine randomized trials (911 adults) found that subjects given carnitine lost on average 1.33 kg more than controls, and that the effect shrank with longer treatment.[5]
Obesity indices (2025): an umbrella review of eight meta-analyses reported modest reductions in body weight, BMI and waist circumference, with very high heterogeneity between studies for weight and BMI.[6]
These are supplementation studies in people, summarized here as scientific background only.
Laboratory research applications
Fatty acid oxidation assays: carnitine-dependent beta-oxidation in isolated mitochondria and cultured cells.
Acylcarnitine analysis: reference material for mass-spectrometry profiling of fatty acid oxidation disorders.
Transporter studies: OCTN2 uptake kinetics in expression systems.
This product is sold for laboratory research and is not intended for human or veterinary use.
Frequently Asked Questions
What is L-Carnitine?
Levocarnitine, a small compound (161.20 g/mol) that carries long-chain fatty acids into mitochondria for beta-oxidation. The body makes it and also obtains it from meat and dairy.
What is the difference between carnitine and L-carnitine?
L-carnitine (levocarnitine, CAS 541-15-1) is the specific stereoisomer, listed in PubChem as (-)-carnitine, that is used in FDA-approved levocarnitine medicines. Ask for the Certificate of Analysis to confirm the form of each batch.
How does L-Carnitine work in the mitochondria?
Fatty acids are moved across the inner mitochondrial membrane as acylcarnitines and released inside for beta-oxidation. When this shuttle fails, long-chain acylcarnitines accumulate.
Does L-Carnitine help with weight loss?
In human supplementation trials, meta-analyses found modest average effects: about 1.3 kg more weight loss than control in one analysis, with results varying widely between studies. This product is for laboratory research only.
Is L-Carnitine an approved drug?
Levocarnitine is approved by the FDA as a prescription medicine, for example as an injection. The research-grade powder sold here is not a drug product.
How should L-Carnitine be stored?
Keep the lyophilized powder at −20 °C in a dry place, protected from moisture.
Scientific References
Longo N, Frigeni M, Pasquali M. Carnitine transport and fatty acid oxidation. Biochim Biophys Acta. 2016;1863(10):2422-35. PubMed
Knottnerus SJG, Bleeker JC, Wüst RCI, et al. Disorders of mitochondrial long-chain fatty acid oxidation and the carnitine shuttle. Rev Endocr Metab Disord. 2018;19(1):93-106. PubMed
Drugs@FDA. Levocarnitine injection, NDA 020182, original approval December 16, 1992 (prescription). Source
Pooyandjoo M, Nouhi M, Shab-Bidar S, et al. The effect of (L-)carnitine on weight loss in adults: a systematic review and meta-analysis of randomized controlled trials. Obes Rev. 2016;17(10):970-6. PubMed
Hamedi-Kalajahi F, Zarezadeh M, Malekahmadi M, et al. The Effect of the L-Carnitine Supplementation on Obesity Indices: An Umbrella Meta-Analysis. Int J Vitam Nutr Res. 2025;95(2):40033. PubMed
Fardet A, Chardigny JM. Plant-based foods as a source of lipotropes for human nutrition: a survey of in vivo studies. Crit Rev Food Sci Nutr. 2013;53(6):535-90. PubMed
Sources are peer-reviewed publications indexed in PubMed and trial registrations on ClinicalTrials.gov. Each citation was checked against its PubMed record.
For research use only. Not for human consumption.
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