Teen Boys and Young Men Are Injecting Peptides in Search of Perfection WSJ What is Melanotan II, the drug that consumers are urged to avoid? 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 Stay Sun Kissed All Year Round with Melanotan 2 Melanotan is a tanning peptide that stimulates the production of melanin in the body to foster a deep, natural tan. This is the