Doctors warn against viral nasal spray tanning trend Nasal tanning sprays and oral tanning drops are often marketed as quick fixes for glowing skin but these products are unregulated in the UK, with unknown ingredients, dosing, and formulation. They have 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