Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn Melanotan What It Is and Its Relation to Skin Cancer 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 Sooo this feels vulnerable to share. I've been taking a very small dose of Melanotan 2 peptide to help build a tan and the last few days I've worn zero Melanotan II Safety: Tanning Injection LIVV Natural