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 Melanotan What It Is and Its Relation to Skin Cancer Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn Melanotan II Peptide Elite Beauty Toledo Suntan Drug Greenlighted for Trials WIRED