Ask the doctor: Are sunless tanning products safe?
Q. I like to look tanned, but I'm somewhat fair-skinned and can't be in the sun much. Are self-tanning lotions and sprays a good idea? Are they safe?
A. Sunless tanning sprays and lotions can make your skin look tanned without exposing it to the sun's harmful ultraviolet (UV) radiation. When you sunbathe, UV rays cause the skin to increase its production of the protective pigment melanin, which manifests itself as a tan. Despite its association with good health and good looks, a tan is actually a sign of skin cell damage, which can increase the risk for skin cancer and accelerate skin aging. The American Academy of Dermatology recommends self-tanning products as an alternative to tanning in UV light from the sun or an indoor tanning bed.
You can buy self-tanning products over the counter and apply them yourself, or you can go to a salon that offers spray-on or airbrush tans. The active ingredient in all of these products is dihydroxyacetone (DHA), a color additive often derived from plant sources that's approved by the FDA for tanning purposes. DHA binds to proteins in the top layer of skin, causing it to darken or stain. Thicker, protein-rich areas of your skin will stain more, so for more even results, you should exfoliate the skin of the elbows, knees, and ankles beforehand, using a washcloth, sponge, or loofah, for example. Because the coloring process takes place only in the surface layers of the skin, your "tan" lasts only as long as those layers stay on your body—five to seven days. After they slough off, you'll need a reapplication.