BBC News Latest News Picks, Toxic tanning "I didn't think I'd get skin cancer" 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 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 II (Tan Jabs): Why They're Not Worth The Risk