Melanotan peptide might seem like the cool thing to doit makes you look tan., But these unregulated injections come with real risks., They can cause unpredictable skin changes, including darkening of Melanotan What It Is and Its Relation to Skin Cancer 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 Safety: Tanning Injection LIVV Natural Tanning Injections: Risks, Side Effects, and Precautions