Erythrulose is a naturally occurring sugar that is often used in cosmetic products, particularly in self-tanning lotions. It works by reacting with the amino acids in the skin's surface, leading to a browning effect similar to that of dihydroxyacetone (DHA). This reaction typically results in a more gradual and even tan. Unlike some other tanning agents, erythrulose is known for producing a more subtle color and may last longer on the skin. It is considered safe for topical use and is suitable for various skin types, making it a popular choice in the beauty industry for achieving a natural-looking tan.