[Self-tanning and sunless tanning products].

Practically all currently available self-tanning products have as their active ingredient dihydroxyacetone (DHA), which may or may not be combined with erythrulose, tyrosine derivatives, and occasionally a naphthoquinone. The resulting skin tone, which resembles a natural tan, is due to chemical combination of the DHA with amino acids in the skin through the Maillard reaction. Polymer pigments known as melanoidins are formed and are fixed in the stratum corneum, where they remain until corneocyte desquamation occurs. The colouring thus achieved is semi-permanent and is well tolerated by skin. While the formulation of such products is complex and their storage difficult, no other substances provide more satisfactory or more lasting results.