L-Erythrulose and dihydroxyacetone (DHA) are very similar in composition, and both react much the same way on the skin surface. L-Erythrulose produces a lighter and slower-developing tan, taking 24 to 48 hours to complete development. When used alone, it fades faster than a DHA-based sunless tan. Some people feel the final tone of L-Erythrulose is slightly redder, and less bronze, than the DHA-based tan. It may be less drying to the skin surface, helping provide a smoother fading tint. When combined with DHA, the resulting sunless tan is said to last longer, fade better, and provide a more cosmetically pleasing color tone. In sunless tanning products, it is incorporated at 1% to 3% levels.
L-Erythrulose reacts on the skin's surface and does not seem to penetrate beyond the dead surface skin layers. Side effects are limited to occasional contact dermatitis in sensitive individuals. In many suspected cases of sensitivity, the reaction is related to other ingredients in the self-tanning product, such as preservatives, dyes, fragrances, or plant-based additives and extracts.