Melanotan (MT) II Melanocortin Receptor Agonist MedChemExpress Melanotan II Skin Pigmentation & Libido 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 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 Melanotan II an overview ScienceDirect Topics