These potent peptides – Melanotan, V.I.P., & Bremelanotide – represent a range of avenues in medical realm. Melanotan 2 is largely used for its ability to promote tanning , leading to a darker tan . Vasoactive Intestinal Peptide acts as a neurotransmitter , modulating vasodilation and possessing certain arousal effects . Finally , PT-141 Vialox