Melanotan II

Non-selective melanocortin agonist — stronger tanning, plus libido (PT-141 was derived from it).

MT2 hits several melanocortin receptors at once, so you get a faster, deeper tan and a libido kick from the same molecule (PT-141 was literally carved out of it to isolate the libido half). That two-for-one is the appeal — and the catch: hitting multiple receptors means more nausea, blood-pressure swings, spontaneous erections, and a harder push on moles and freckles than MT1. It works well; it's just less tidy. Mole monitoring matters more here than with MT1.