Emerging Threat: Melanotan, Repackaging, and Online Sales What are the mechanism of action and side effects of Melanotan 2 (afamelanotide)? 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 Don't risk using tanning products containing melanotan Therapeutic Goods Administration (TGA)