allantoin

Allantoin is a diureide of glyoxylate with the chemical formula C4H6N4O3. It is a naturally occurring metabolite produced in the catabolic pathways of purines in many organisms. In species that possess the enzyme uricase, uric acid is oxidized to allantoin, which is excreted in urine; in other organisms, allantoin can still be found in trace amounts in urine and in various plants. Allantoin also occurs in certain plant tissues, including roots of some species, where it is believed to participate in metabolism and stress responses. Industrially, allantoin can be produced by microbial fermentation or by chemical oxidation of uric acid.

In cosmetics and dermatology, allantoin is valued as a skin-conditioning and soothing agent. It is used for its humectant properties and its purported ability to support moisture retention and the healing of irritated or damaged skin. Products containing allantoin appear in creams, lotions, ointments, and other topical formulations. Typical cosmetic concentrations range from about 0.1% to 2%, with higher concentrations used in some OTC preparations.

Safety and regulatory status are favorable for topical use. Allantoin is generally regarded as safe and non-irritating, with a long history of cosmetic use and extensive toxicology data supporting its safety. It is approved for use in cosmetics in many jurisdictions and is often included among skin-conditioning agents. While it is not a cure for underlying conditions, allantoin is commonly employed to improve comfort, hydration, and minor skin irritation in a variety of over-the-counter and prescription products.