Skin whitening is the practice of using substances, mixtures or physical treatments to lighten the color of the skin. Skin whitening treatments work by reducing the melanin content of the skin. Many agents have been shown to be effective in skin whitening; Some have beneficial side effects (for example: they are antioxidants, nutrients, or they lower the risk of some types of cancer); Some are a significant health risk (for example, those containing mercury).
Melanogenesis inhibitors have been discovered and developed through various methods, including: selection of synthetic chemical libraries (occasionally high-throughput screening), screening of plant extracts, computational (in silico) search, as a side effect of Previously known drugs and screening of structural analogs of previously known inhibitors of tyrosinase based on knowledge (at different grades) of their structure-activity relationship. Therefore, the development and discovery of melanogenesis inhibitors illustrates many of the methods used in drug design. Some of the most potent competitive reversible inhibitors of tyrosinase are synthetic compounds with a potency hundreds of times that of kojic acid.