Improved formulations of sunless or self-tanning products are a viable alternative to UV induced tanning. Dihydroxyacetone (DHA) is the primary active ingredient in these products. The chemistry of DHA, formulation, mechanism of action and application are described. Additional ingredient additives, sunscreen activity, indications, and safety issues are also discussed. The Maillard or browning reaction occurs in the stratum corneum forming melanoidins. Maximal darkening occurs within 24 h. Successive applications will deepen coloration. Different body sites require varying amounts of product. Repeat applications every few days are required to maintain the depth of color. Careful product formulation and individual application are required for achieving an aesthetically pleasing result. Individuals with skin phototypes II and II achieve the most satisfying results. DHA provides minimal UVB and UVA protection. Sunscreen ingredients may be present in formulations providing only short-term protection. Individuals need to be informed of these limitations. These products have a benign safety profile. Contact irritation or allergy is more likely to be the result of other ingredients in these formulations as opposed to DHA. Alternative agents for increasing skin pigmentation are briefly reviewed.