Teen Boys and Young Men Are Injecting Peptides in Search of Perfection WSJ We are OBSESSING over this Melanotan II transformation After only 14 days using the Melanotan injections combined with one day of laying in the sun, can you believe the difference?? Nothing 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 longer lasting than Melanotan II Safety: Tanning Injection LIVV Natural Understanding Injection Tan and Melanotan 2