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 Lets look at sunless tanning, ., Firstly theres the injections and nasal sprays which typically have an active ingredient called melanotan. This is a synthetic compound that stimulates the Melanotan ll 10mg 4 Pack Lyophilized powder USA Made 2 x Melanotan 2 injection kit MELANOTAN2AUSTRALIA