Dihydroxyacetone binds to proteins in the stratum corneum of the skin imparting a non-toxic, bronze color to the skin. The resulting pigments are called melanoidins, or brown chromophores. Since the 1980's, improved formulations of sunless tanners are available due to more purified sources of DHA and refinements in the DHA manufacturing process. The color is not removed by simple washing, swimming, or natural perspiration, but it only lasts for 5 to 7 days, as skin cells are continuously being shed. Exfoliation, tape stripping, prolonged water submersion, or heavy sweating can lighten the tan, as these all contribute to rapid dead skin cell pealing. Indeed, patients may opt to reapply the product on a regular basis (such as daily or every fourth day) to maintain the skin color.Possible improvements in dihydroxyacetone products include addition of perfluoropolyether phosphate to lower the formulation's pH, exfoliation with polyethylene beads prior to treatment, wiping skin with an acidic toner just prior to application, addition of strong antioxidants such as caffeic acid phenethyl ester, using a polymer base, and pretreatment of the skin with amino acids to increase binding sites of DHA to the skin.Tanned skin remains a desirable quest by a large segment of the population in Western countries. Several products are being marketed for that coveted dark skin tone without direct ultraviolet tanning. The list of sunless-or self-tanners includes dihydroxyacetone (DHA), color cosmetics, henna, juglone, bronzing gels, color washes, facial highlighters, bronzing powders, tinted moisturizers, and facial foundations [1]. As DHA is the most common active agent in sunless tanners, and as it is neither toxic nor absorbed through the skin into the body (as it does not penetrate beyond the stratum corneum), this manuscript concentrates on this Food and Drug Administration-approved product.DHA, also named dihydroxy-2 propanone, is a simple three carbon sugar which is derived from plant sources such as sugar beets and sugar cane by the fermentation of glycerin. It binds to proteins in the stratum corneum of the skin imparting a bronze color to the skin. This skin browning effect is non-toxic. DHA reacts chemically with the amino acid groups, which are part of the protein containing keratin layer on the skin surface. Various amino acids react differently to DHA, producing different tones of coloration from yellow to brown. The resulting pigments are called melanoidins, or brown chromophores. These are similar in coloration to melanin, the natural substance in the deeper skin layers. The mechanism of this artificial tanning is totally different from natural tanning, which is based on the increase in melanin pigmentation secondary to ultraviolet exposure. On passing, this chemical reaction of an amino acid with a reducing sugar is often referred to as a Maillard reaction.