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 Melanotan II (MT II) Peptide Therapy Beverly Hills Melanotan II (Tan Jabs): Why They're Not Worth The Risk What is Melanotan II, the drug that consumers are urged to avoid? Dangerous 'Barbie drug' Melanotan II sparks crackdown on social media influencers ABC News