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 Rise in use of 'dangerous' tanning injection Channel 4 News 1 x Melanotan 2 Injection Melanotan South Africa 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 Injection What does it do?