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 You Should Avoid Using Nasal Tanning Sprays Australia's health regulator has issued an urgent alert against Melanotan a dangerous tanning product. "This stuff that people are getting is unlicensedand off the black market." Dr Greg Goodman Melanotan II GenScript