Carnosine in skin care: effects and limits of the evidence
Clinical review pending
Carnosine is used as an antioxidant ingredient in serums and creams. What laboratory studies show and which clinical evidence is missing.
What is carnosine?
Carnosine is a small peptide made from two amino acids, beta-alanine and histidine. It occurs naturally in the body, particularly in the muscles and brain. In skin care, it is used as an antioxidant ingredient, often in products for visibly aged skin or skin affected by environmental exposure. In this setting, it serves as a cosmetic ingredient. Ingredient lists usually identify it as “Carnosine.”
How is carnosine supposed to work?
Laboratory studies mainly suggest antioxidant and anti-glycation properties. As an antioxidant, carnosine can neutralize reactive oxygen species. These unstable molecules arise from sources including UV light and environmental exposure and are associated with visible skin aging. In an ex vivo study of human skin 1, topically applied carnosine reduced markers of UV-related oxidative stress.
Carnosine is also intended to limit glycation, a process in which sugar molecules bind to proteins such as collagen. This produces advanced glycation end products, which can stiffen proteins and impair their function. Carnosine slowed this process in laboratory models. This underlies the idea that it might help skin look more supple. For finished cosmetics, the claimed effects concern appearance, such as visibly firmer skin or a brighter, more even complexion.
Is carnosine FDA-approved?
According to the source text, drug approval is not required for the cosmetic use described here. The US Food and Drug Administration does not preapprove cosmetic products and ingredients as it does medicines. Cosmetic claims concern appearance and how skin feels. Claims about changing the body’s structure or function, by contrast, can lead to classification as a drug. The use of carnosine discussed here concerns the appearance of the skin.
What is carnosine used for?
Carnosine is found in antioxidant skin care and products marketed as anti-aging, usually serums and moisturizers. These are intended to counter dull or uneven-looking skin associated with oxidative stress and make skin appear firmer and smoother. Carnosine is often combined with other antioxidants.
What do the studies show?
Most evidence comes from laboratory experiments and studies of removed skin tissue, rather than large clinical trials. An ex vivo human skin study indexed in PubMed 1 found fewer UV-related reactive oxygen species and lower glycation markers after topical carnosine application. Independent, well-controlled studies of carnosine alone measuring wrinkles or skin firmness in people are lacking. Some studies test multi-ingredient formulations containing carnosine. Its individual contribution is difficult to determine from them.
What side effects are possible?
At cosmetic concentrations, carnosine applied to the skin is generally considered well tolerated and minimally irritating. People with sensitive or reactive skin may find it useful to try a new product on a small area first. Individual reactions are still possible.
References cited in the source text
Sources: an ex-vivo human skin study of topical carnosine and UV-induced oxidative stress (Girardi et al., Photochemistry and Photobiology, 2023, DOI: 10.1111/php.13850 1), indexed on PubMed; and cosmetic ingredient reference data on carnosine.
Provenance and editorial review status
Adapted for Nutrient Desk from the source article. The claims and source attributions in the original text still require clinical review. This draft has not been cleared for indexing.