Melanotan II: Tanning injections, nasal sprays harmful to health Melanotan ii: Health Benefits, Side Effects, Uses, Dose & Precautions 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 No, you don't need the 'Barbie drug' to tan, whatever TikTok says. Here's why melanotan II is so risky