Tanning

Ingredients with the tanning function give the skin a darker, "tanned" shade without the involvement of ultraviolet light. They usually work on the surface of the stratum corneum: they react with the amino acids of the skin, resulting in the formation of colored compounds and gradually the effect of artificial tanning appears. At the same time, such substances do not color the hair and do not change the structure of the skin, but primarily affect its appearance; they have a minimal effect on the texture of the formula and are more often used as shade assets. The European CosIng database classifies tanning as a cosmetic ingredient function, and the FDA specifically mentions sunless tanners as a category of cosmetic products. (single-market-economy.ec.europa.eu)

The most typical example is Dihydroxyacetone (DHA), a simple ketosaccharide that is widely used in self—tanning products and is able to form a brownish tone on the skin. Another common example is Erythrulose; it is also a ketosaccharide, which is often combined with DHA to make the shade appear softer and more uniform. Since the effect is associated with the coloring of the upper layers of the skin, it is temporary and gradually disappears with the natural renewal of the epidermis. It is important to understand that such ingredients create a visual tone, but they do not replace sunscreen by themselves. (pubchem.ncbi.nlm.nih.gov)