What is the purpose of using a tanning barrier lotion before applying self-tanner?

Using a tanning barrier lotion before applying self-tanner serves the important function of preventing uneven staining on areas of the body that tend to absorb more product, such as elbows, knees, ankles, and the back of the hands. These areas often have rougher skin or may be drier than the rest of the body, leading to darker patches if not properly prepared. By applying a barrier lotion, these high-absorption areas are coated in a thin layer of moisture, which helps to even out the application of the self-tanner, allowing for a more uniform finish.

While moisturizing the skin can aid absorption and create a base layer, the primary purpose of the barrier lotion is targeted toward those specific areas prone to uneven application, ensuring that the overall tan looks more natural and less splotchy. This consideration is particularly important for achieving a professional-looking tan, as uneven patches can be a common concern with self-tanning products.