Sunless tanning (also known as spray tanning, self tanning, fake tanning, or UV-free tanning) refers to the application of chemicals to the skin to produce an effect similar in appearance to a suntan.

The popularity of sunless tanning has risen since the 1960s after links were made by health authorities between exposure to the sun, and other sun tanning methods, such as sunbeds or tanning beds, and the incidence of skin cancer.

The most effective sunless tanning involves the use of lotions and sprays that contain dihydroxyacetone (DHA) as the active ingredient. DHA is not a dye, stain or paint, but causes a chemical reaction with 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 require exposure to ultraviolet light to initiate the color change. The effect is temporary and will fade gradually over 3 to 10 days.

Some products use erythrulose combined with DHA. Erythrulose works identically to DHA on the skin surface, but develops more slowly. The two chemicals used together may produce a longer lasting sunless tan.These products can be applied at home, in the form of gels, lotions, mousses, sprays and wipes. Best results are obtained when applied to clean, dry skin. Bathing and swimming should be avoided until product is fully absorbed, which varies from one to six hours. More DHA is absorbed by the thicker skin on the hands and feet, so those areas should be skipped or cleaned immediately after application.

Tanning lotions can be classified as bronzers, accelerators, and tingling lotions. Tingling lotions refer to indoor tanning lotion accelerators and maximizers that produce a tingling sensation when they are applied. It is believed that the tingle factor increases blood flow to the upper layers of the skin which brings more oxygen and affects melanin. This tingling sensation will vary depending on the skin type from mild to very strong.

Professional spraytans applications are available from spas, salons and gymnasiums by both hand held sprayer and in the form of sunless or UV-Free spray booths. The enclosed booth, which resembles an enclosed shower stall, sprays the sunless tanning solution over the entire body.