Metabolites and small molecules
L-carnitine
L-carnitine is a quaternary ammonium compound (formula C7H15NO3) that transports long-chain fatty acids into mitochondria as part of the carnitine shuttle.
- TypeSmall molecule
- FormulaC7H15NO3
- Average mass161.20 g/mol
- CAS541-15-1
- Vesta listings3
Reference page for laboratory use · updated 2026-10-30
Overview
L-carnitine at a glance
It is a small, water-soluble molecule that is found in all animal tissues and is not a peptide. Its metabolic functions are described in reviews of fatty acid oxidation.
In the laboratory it is used as a metabolic reagent and as a standard in carnitine and acylcarnitine assays.
Structure
The biologically active form is the L enantiomer (levocarnitine). The D enantiomer is inactive and can inhibit carnitine-dependent processes, so a COA should state the enantiomeric purity.
Identity
Identity data
| Name | L-carnitine |
|---|---|
| Also written as | Levocarnitine |
| Type | Small molecule |
| Research area | Metabolites and small molecules |
| Molecular formula | C7H15NO3 |
| Monoisotopic mass | 161.1052 Da |
| Average molecular weight | 161.20 g/mol |
| CAS number | 541-15-1, 44985-71-9 |
| PubChem record | CID 10917 |
The formula comes from the PubChem record; monoisotopic mass is calculated from the formula and the average mass uses standard atomic weights. Reference data retrieved on 2026-10-30. Compare these values with the batch certificate of analysis, using the compound identity file template.
Expected values
Mass spectrometry reference
Ions calculated from the monoisotopic mass 161.1052 Da. Use them to check an LC-MS result; for larger peptides the instrument usually reports a deconvoluted mass close to 161.2 Da instead.
| Ion | m/z |
|---|---|
| [M+H]+ | 162.1125 |
| [M+Na]+ | 184.0944 |
| [M+K]+ | 200.0684 |
Read the guide to average and monoisotopic mass for how these values are calculated.
Quality
Analytical notes for batch documents
- Carnitine is analysed by HPLC with derivatisation or by LC-MS, not by direct UV at 214 nm.
- The powder is hygroscopic; water content should be reported.
- The molecular weight of a vial of powder includes counter-ions and water; the share of the powder that is peptide is the net peptide content.
Vesta listings
L-carnitine formats and prices
| Product | Per vial | SKU | Price per kit | Price per vial |
|---|---|---|---|---|
| L-carnitine | 400 mg | LC400 | $44.78 | $4.48 |
| L-carnitine | 600 mg | LC600 | $52.24 | $5.22 |
| L-carnitine | 1200 mg | LC1200 | $78.36 | $7.84 |
Prices are per kit of 10 vials in US dollars. Shipping is paid by the customer and is shown in the cart. Volume savings of 5 %, 8 % and 10 % apply from $350.00, $600.00 and $1,000.00. See the full price list.
Published literature
Selected scientific literature
Bibliographic details were read from PubMed on 2026-10-30. The papers are listed for scientific reference; Vesta makes no claim about the use of its research materials in people or animals.
- L-carnitine--metabolic functions and meaning in humans lifePekala J, Patkowska-Sokoła B, Bodkowski R et al. · Curr Drug Metab · 2011 · PMID 21561431
Questions
Frequently asked questions
What is L-carnitine?
L-carnitine is a quaternary ammonium compound (formula C7H15NO3) that transports long-chain fatty acids into mitochondria as part of the carnitine shuttle.
What is the molecular weight of L-carnitine?
L-carnitine has the formula C7H15NO3, an average molecular weight of 161.20 g/mol and a monoisotopic mass of 161.1052 Da. A salt form, a different counter-ion or a metal complex changes the molecular weight printed on a certificate of analysis, so compare like with like.
How can I check the identity of a batch of L-carnitine?
Compare the intact mass measured by LC-MS with the expected values on this page, for example [M+Na]+ at m/z 184.0944. Confirm that one main HPLC peak carries that mass and that the batch code on the report matches the vial. The guides on mass spectrometry and on certificates of analysis explain each step.
Which L-carnitine products does Vesta list?
Vesta lists 3 products for L-carnitine: 400 mg, 600 mg, 1200 mg per vial in kits of 10 vials. Prices are shown per kit in US dollars, and shipping is paid by the customer.