Melanotan II monograph

Melanotan II is a synthetic melanocortin receptor agonist, a truncated cyclic analog of α-MSH. It darkens skin by driving melanogenesis, which is why bodybuilders use it for contest color. It is not a muscle-building drug and it has no performance indication. The same melanocortin signaling can raise libido and cause erections without sexual stimulation. Nausea and yawning are the most consistent human side effects — and some athletes have even treated the nausea as an appetite-suppressant tool in contest prep. The real safety flags are changing moles, priapism, and the gray-market vial itself. It is not FDA-approved, so dose and identity are often whatever the seller printed on the label.