Melanotan II: Tanning, Sexual Health Benefits, & Safety Concerns Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn 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 Melanotan Tanning Injections The Low Down Lynton Lasers You Should Avoid Using Nasal Tanning Sprays