Melanotan Side Effects What Researchers Must Know Structure of Melanotan II and bremelanotide. Download Scientific Diagram Maintaining Tan with Melanotan 1: Dosage, Results, and Differences from Melanotan 2 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 Who's tan is reay for summer. This peptide can help.