Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn Before you take tanning pills, listen to this!, The active ingredient in tanning pills are known as Canthaxanthin, and although this ingredient is approved by the FDA, the high amount of this Tanning from the inside out = Highly Dangerous and Illegal! Many products advertised on social media platforms promising a tan from the inside out or a tan without sun such Melanotan ii hi res stock photography and images Alamy