The most effective products available are sunless tanning or self tanning lotions that contain dihydroxyacetone (DHA) as the active ingredient. The tan is not a dye, stain or paint, but a chemical reaction between the DHA and the amino acids in the dead layer on the skin surface. This is similar to a reaction well known to food chemists called the Maillard reaction. This refers to the browning process during food manufacturing and storage. It does not involve skin pigmentation nor does it need UV exposure to initiate the color change. The tan is temporary and will fade gradually over 3 to 10 days. The two chemicals used together may produce a longer lasting sunless tan.