Dihydroxyacetone, also known as DHA or glycerone, is a common active ingredient in tanning lotions or sprays designed for sunless use. A simple carbohydrate, dihydroxyacetone is crated from sugar beets or sugar cane and the glycerin fermentation process. It can also be used in wine making.
Though colorless, DHA stains the skin on contact. It does so by reacting with dead skin cells in the epidermis. This creates the brown color associated with a dihydroxyacetone tanning agent. Since the dead skin cells fall off the body within a week, the color, too, fades as quickly. This is why people who utilize sunless tanners must apply the products so often.
In most sunless tanning products, dihydroxyacetone is used as the primary ingredient. It can be used alone for the desired effect. Other tanning additives, such as erythrulose, may also be used in conjunction with DHA for more specific results. With either product, tanning typically takes two to four hours to start appearing on the user's skin. Following the initial appearance, the color may darken for an additional 24 to 72 hours.
The use of DHA to alter skin tone is considered a healthier alternative to sun tanning or using commercial tanning beds. Though the carbohydrate does no damage to the skin itself, it can still present a health hazard. Within the 24 hours following application, the skin becomes highly sensitive and susceptible to sun damage. During this period of time, users of the product are advised to wear sunblock, and to remain indoors for as long as possible.
Sprays and lotions are a popular choice for users of sunless tanning products. Dihydroxyacetone is also available as a gel, cosmetic wipe, or mousse. Some people may opt to have it applied professionally; in this case, it may be administered through any of the previous means or via an airbrush or tanning booth.
While DHA is generally considered to be nontoxic and safe for human use, it can cause irritation if placed on sensitive parts of the body. The eye and lip areas, as well as any body parts covered with mucus membranes, should be kept free of the product. Inhalation and ingestion of the ingredient are also strongly discouraged.
During the wine making process, the formation of dihydroxyacetone results in a sweetness added to the finished product. It can also add a unique aroma to the wine. This scent has been described by as "crust-like."