Is L-carnitine harmful to the skin?

Does topical application of L-carnitine carry any risks?

L-carnitine is an amino acid present in the body, mainly in muscles and the heart. It plays a key role in fatty acid metabolism by transporting fatty acids into mitochondria for energy production. These properties also make it a common ingredient in skincare formulations. But does topical application of L-carnitine carry risks? Explore this question.

Published on July 4, 2025, updated on July 4, 2025, by Jamal, PhD, Doctor of human pathology and infectious diseases — 5 min of reading

Why is L-carnitine used in skincare?

In the skincare market, L-carnitine has become a preferred ingredient to address skin imbalances linked to lipid metabolism. Present in the body, this molecule plays a key role in transporting fatty acids to the mitochondria, where they convert to energy. Applied topically, it uses the same mechanism to promote lipid breakdown in subcutaneous tissues, making it a valued active in treatments targeting cellulite. The benefits of L-carnitine for the skin do not end there: studies show it can also modulate sebum production, a property useful for oily skin.

Did you know? The carnitine exists in two stereoisomeric forms, D-carnitine and L-carnitine, but only the latter is biologically active.

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What precautions should be taken when applying L-carnitine topically?

To date, L-carnitine is considered a well-tolerated cosmetic ingredient, in facial products designed for oily or blemish-prone skin. Several studies have tested this compound at concentrations between 0.5% and 2%, without causing adverse skin reactions. L-carnitine is also suitable for sensitive skin, as no reports of redness, irritation, or itching have been recorded after topical application of a product containing this ingredient.

Regarding its use in vulnerable populations, such as pregnant or lactating individuals and young children, available data are limited or nonexistent. However, L-carnitine topical application is not considered a hazardous skin care ingredient during pregnancy, unlike retinoids or salicylic acid, for example. There are a priori no contraindications to the use of L-carnitine by pregnant individuals, although, as a precaution, consulting a healthcare provider remains advisable.

This refers to topical application of L-carnitine rather than oral administration. Oral intake of L-carnitine during pregnancy should be assessed on a case-by-case basis with a physician.