Melanotan is not a tan. It's an unregulated peptide with real risk. As a dermatologist, here's the reality: It has been linked to new and changing moles including cases of Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn The Tanning Drug What Patients Should Know 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 Melanotanassociated melanoma in situ Ong 2012 Australasian Journal of Dermatology Wiley Online Library