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 Thinking about that tanning nasal spray? Don't. Unregulated nasal tanning sprays are being sold online, claiming to give you a sun kissed glow. But they're risky and illegal. According to the Chartered Trading Eruptive naevi and darkening of preexisting naevi 24 h after a single mono dose injection of melanotan II Semantic Scholar Warning issued over increased use of 'Barbie drug'