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 Illegal tanning nasal spray not a 'harmless alternative' to sunbaking, says TGA ABC News Eruptive naevi and darkening of preexisting naevi 24 h after a single mono dose injection of melanotan II Semantic Scholar Melanotan I