Say NO to tanning injections and nasal sprays. They are illegal in the UK and have serious, harmful side effects 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 is not a tan. It's an unregulated peptide with real risk. As a dermatologist, here's the reality: It has been linked to new and changing moles including cases of Is Melanotan the New Solarium for a Perfect Tan?