Dihydroxyacetone (DHA) is a colorless sugar and the main active in self-tanning products. It reacts with amino acids in the stratum corneum to create a temporary brown pigment. This pigment mimics the look of a natural tan. The tanning effect develops within 2 to 4 hours and lasts for 3 to 7 days. As the skin exfoliates, the color gradually fades. Experts consider DHA non-toxic and safe for topical use at standard concentrations. Brands use it in self-tanning lotions, sprays, and mousses as a UV-free bronzing solution.
