Dangerous' tanning products promoted by influencers 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 Nasal tanning sprays linked to skin cancer, trading standards officers warn Consumer affairs The Guardian MD breaking down Melanotan II Part 2 of my peptide series. The research, the risks, the reality. Long term safety data? Nonexistent.