Indoor tanning lotions provide a safe way to get that desired summertime glow. The lotions contain an ingredient called DHA, or dihydroxyacetone, which reacts with your skin and triggers a change in skin color. This reaction occurs whether you are indoors or outdoors.
Precautions for Outdoor Use
Although using a sunless tanner will bronze your skin when you apply it outside, it won't protect you from the sun's UV rays unless it also contains sunscreen. Most indoor tanning lotions with sunscreen are not water or sweat resistant, so you need to apply water-resistant sunscreen after the indoor lotion has fully dried.