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 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 Is this injectable tanning drug safe to use? Gen Z adults appear more likely to tan, but experts warn of risks for UV exposure and 'viral' tanning trends KBIA