Melanotan 2 Pigmentation pathways, Appetite regulation Research A peptide that makes you tan. Sounds great. What could go wrong? When its activating your melanocytes to increase pigment in your skin, it may also be causing cancer melanoma. Ive had patients have Nasal tanning sprays linked to skin cancer, trading standards officers warn Consumer affairs The Guardian 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