Function
While Melanotan II is studied as a tanning and libido-enhancing agent; increases melanin production and can reduce food intake and modulate sexual arousal in animal models and humans3545, Tirzepatide is approved for type 2 diabetes and obesity, producing larger HbA1c and body-weight reductions than semaglutide in head-to-head trials24.
Mechanism
While Melanotan II works as a cyclic heptapeptide melanocortin analog (Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2) that acts as a non-selective, high-potency agonist at MC1R, MC3R, MC4R, and MC5R, influencing pigmentation, appetite, and sexual behavior3545, Tirzepatide is a 39-amino-acid synthetic peptide primarily based on GIP sequence with C20 fatty diacid conjugation that acts as a dual agonist at GIP and GLP-1 receptors, enhancing glucose-dependent insulin secretion, suppressing glucagon, delaying gastric emptying, and reducing appetite24.