Do tanning pills really work? Simply put, yes. But although the FDA has approved the use of canthaxanthin in food, it hasn't approve its use as a tanning agent. When used as a color additive, only small amounts of canthaxanthin are required. As a tanning agent, however, larger quantities are used, which can have harmful side effects.
Research shows that consuming large amounts of canthaxanthin can cause damage to the eyes because it settles not only in the skin, but also in the retinas. This can cause canthaxanthin retinopathy, the formation of crystals in the retinas, which can affect eyesight. Other side effects include stomach cramps, nausea and diarrhea [source: Mayo Clinic].
As for the pills' effectiveness, you won't see results in one day. Two weeks of consistent use is necessary to allow enough dye to build up in your skin. On the other hand, if you decide your skin tone is a little too orange, it'll take two weeks after you quit taking the pills for your skin to return to its normal shade.
So, what's the safest way to tan? Your best bet is a cosmetic product such as a tanning lotion or powder bronzer. To learn more about tanning pills and other tanning methods, check out the links on the following page.