Say NO to tanning injections and nasal sprays. They are illegal in the UK and have serious, harmful side effects 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 Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn You Should Avoid Using Nasal Tanning Sprays