Dihydroxyacetone (DHA) is a colorless sugar and the primary active ingredient in self-tanning formulations. It undergoes a Maillard reaction with the amino acids in the epidermal layer, specifically within the stratum corneum, resulting in the formation of a temporary brown pigmentation that mimics the appearance of a tan. The tanning effect typically develops within 2-4 hours post-application and persists for 3-7 days, gradually fading as the skin naturally exfoliates. DHA is considered non-toxic and safe for topical application when used within established concentrations, and is widely utilized in self-tanning lotions, sprays, and mousses for UV-free skin bronzing.
