dihydroxyacétone

Dihydroxyacetone (DHA) is a simple three-carbon ketone with two hydroxyl groups, commonly represented as HO-CH2-C(=O)-CH2-OH. Its chemical formula is C3H6O3, and it is often referred to by its abbreviation DHA or, in cosmetic contexts, as dihydroxyacetone. In aqueous solution, DHA can undergo tautomerization and interconvert with glyceraldehyde through enediol intermediates, a process related to Lobry de Bruyn–van Ekenstein transformations.

DHA is typically produced commercially by oxidation of glycerol, and it can also be generated via fermentation routes from glycerol or related substrates. It is highly soluble in water and is used in various formulations due to its stability and reactivity with skin components.

A primary use of DHA is as the active tanning agent in sunless or self-tanning products. Upon topical application, DHA reacts with amino acids in the stratum corneum through Maillard-type reactions, producing brown pigments that simulate a tan. The coloration usually develops within a few hours and can last several days, gradually fading as skin cells are shed. In consumer products, DHA is commonly used at low to moderate concentrations (typically a few percent).

Safety and regulation: DHA is widely used in cosmetics for external application. Regulatory guidance generally supports topical use when products are formulated and used as directed, with attention to avoiding inhalation and contact with eyes. Some individuals may experience skin irritation or allergic reactions; products should be used with standard patch testing and according to label directions.