Products
Dihydroxyacetone (DHA) is the active ingredient in most self-tanning products, which are commercially available in the form of lotions, sprays and gels, among others. Its effect on the skin was first discovered in the 1950s by Eva Wittgenstein in Cincinnati.
Structure and properties
Dihydroxyacetone (C3H6O3, Mr = 90.1 g/mol) is a simple carbohydrate belonging to the monosaccharides and the ketoses. The triose exists as a white, crystalline, hygroscopic powder with a typical odor and a sweet taste and is readily soluble in water. Dihydroxyacetone can be produced by the oxidation of glycerol and is therefore also known as glycerone.
Effects
Dihydroxyacetone reacts with amino groups of amino acids contained in proteins and peptides in the stratum corneum of the skin, thereby coloring the skin gold to brownish. This is a Maillard reaction in which the so-called melanoidins are formed. The strength of the tanning depends on the one hand on the product concentration. The higher the concentration, the stronger the effect. On the other hand, tanning also correlates with the thickness of the stratum corneum – the thicker the more intense. Thick areas of skin are found, for example, on the elbows, knees, palms, wrists and soles of the feet. The coloration also remains longer there. The effects become visible after one hour and reach a maximum after about 24 hours. With the natural exfoliation of the skin, the coloring disappears after about a week. Self-tanning does not protect against UV radiation. Therefore, if necessary, a sunscreen must be used in addition.
Areas of application
For temporary cosmetic tanning of the skin.
Dosage
- Exfoliation should be performed before application.
- Wash and dry the skin beforehand.
- Avoid horny areas or apply thinly.
- Allow product to absorb completely.
- Wash hands after application or wear gloves for application to avoid discoloration of the palms.
Adverse effects
Possible adverse effects include an uneven or orange tan, tanning in undesirable areas, and streaks and spots on the skin. Some individuals fail to achieve the desired effect.