Nasal tanners claim to work by using Melanotan II, a chemical that darkens skin pigmentation. It is illegal to sell medicinal products containing Melanotan II in the UK but since the tanners are sold Melanotan II (MT 2) Nasal Spray 10mg 10 mL VPeptide MT 2 Nasal Spray Canada: Ultra Pure Melanotan II Peptide for Pigmentation & Peptide Pathway Research You Should Avoid Using Nasal Tanning Sprays Nasal tanning sprays linked to skin cancer, trading standards officers warn Consumer affairs The Guardian