Tanning oil works intensify ultraviolet rays onto the skin which accelerates the tanning process. The oil increases the production of melanin in the body which is done by accelerating melanocytes to produce melanin.
Melanin is the pigment that gives skin color. People with pale or very light skin have very little melanin, whereas the darker someone’s skin is, the higher the level of melanin their skin has.
Most tanning oils contain moisturizers in them which help in the tanning process. Moisturized skin has a tendency to tan better as opposed to dry skin which may burn when exposed to UV rays instead of tanning.