L-Erythrulose is a natural keto-sugar used in sunless tanning cosmetics. Erythrulose induces a Maillard-like reaction with amino groups in the upper layers of the epidermis which produces a temporary browning effect with an appearance similar to a natural sun tan. Tanned appearance typically lasts from two to ten days, depending on application and skin condition. Erythrulose sunless tanning helps reduce the skin cancer risk, cellular damage and premature aging associated with traditional tanning due to exposure to harmful UV rays. Erythrulose also helps avoid streaking and drying effects caused by other sunless tanning products such as dihydroxyacetone (DHA).