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 Emerging Threat: Melanotan, Repackaging, and Online Sales FDA Fast Facts Warning issued over increased use of 'Barbie drug' Insights into Tanning Biology and Tanning Products JCAD The Journal of Clinical and Aesthetic Dermatology What are 'melanotan' injections? Explaining the controversial tanning drug Dazed