What is the 'Barbie drug' and should authorities be worried? ABC News Imagine just wanting to be jacked and tan and you end up like this? Melanotan II is a peptide that increases the melanin in your skin and can give men a boner that Pyoderma Gangrenosum Secondary to Melanotan Cureus 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