Tanning pills come in three forms: some contain caretenoid pigments, some may contain tyrosine and the others contain nothing. The fact is that melanin does not get generated by any of these organic compounds. Melanin is only developed either by genes or by the UV rays of the sun. If you have tried taking these pills, I urge you to stop them. They have adverse side effects and you will have faced troubles later on.
A. Side effects of tanning pills containing caretenoid: Caretenoid is an orange pigment which plays no role in melanin formation. Instead they provide a pale, yellowish irregular color to your skin and you look so awkward. This happens due to the deposition of the caretenoid molecules on the fat layer under your skin. Sometimes it may be orange too. So you will get an unique orange tan! The accumulation of the pigments in the retina harm your eyes and excessive deposition will lead to blindness. Mostly the pills contain canthaxanthin or lycopene as caretenoid color pigments and these are not friendly to your body.
B. Side effects of tanning pills containing tyrosine: Tyrosine is an amino acid and the tanning pills claim that they help in melanin production. This is a rubbish assertion. Excessive tyrosine may be toxic to the central nervous system and may damage the brain too.
C. Side effects of tanning pills containing neither of the above mentioned chemicals: These pills mostly cause allergic side effects. Your skin may develop unwanted acne and may be quite embarrassing.
Tanning pills are the worst sunless tanning products. The pills act like slow poison that harms you in manner you cannot track and suddenly the symptoms arise and it becomes very cumbersome to treat it at all. Avoid using tanning pills before its too late.