Melanotan and Melanotan-II are both analogs of the peptide hormone alpha melanocyte stimulating hormone (*-MSH) that tend to induce skin tanning. Unlike Melanotan, Melanotan-II has the additional effect of increasing libido. Melanotan II has aphrodisiac properties. - See more at: http://www.avivasysbio.com/sd/tds/html_datasheet.php?sku=OPPA01053