Here's the part nobody explains when they're selling you the "Barbie drug.", , Melanotan 2 is a synthetic peptide that mimics alpha MSH a hormone your body already makes to tell your skin cells to Melanotan II (Tan Jabs): Why They're Not Worth The Risk Eruptive Dysplastic Nevi Following Melanotan Use Actas Dermo Sifiliogrficas 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