Melatonin 2 Tan Before and After TikTok Your body already makes a hormone that tells your skin to tan. Melanotan 2 is a synthetic peptide engineered to mimic that hormone but in a version that's more potent and longer lasting than It doesn't take much to fall down the Barbie Drug rabbit hole. In self tanner subreddits and on TikTok Shop, the tanning injectionaka Melanotan IIis marketed as a self tanner alternative that works by Dangerous' tanning products promoted by influencers