Changes in Oral Mucosa Associated with Melanotan II Injections: A Case Report 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 I accidentally undid years of skin work and didnt realize it until it was too late., At the beginning of November, I started taking melanotan 2 and honestly?, I loved it., My tan deepened 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