Melanotan II
Non-selective melanocortin agonist — MC1R (tanning), MC3R (energy), MC4R (sexual function, appetite). No FDA-approved form. Derivative PT-141 achieved FDA approval via MC4R pathway. Broader receptor profile than Melanotan I with more off-target effects.
Melanotan II is a synthetic cyclic heptapeptide analog of alpha-MSH with non-selective agonist activity at MC1R, MC3R, and MC4R. Unlike the selective MC1R profile of Melanotan I, MT-II’s broader receptor engagement produces tanning (MC1R), energy modulation (MC3R), and sexual arousal plus appetite suppression (MC4R).
This broader activity makes MT-II potent but produces more side effects than its selective analog — nausea, spontaneous erections, facial flushing, and hyperpigmentation. MT-II has never received FDA or EMA approval for any indication. PT-141 (bremelanotide) is an FDA-approved derivative that targets MC4R more selectively for hypoactive sexual desire disorder (HSDD) in premenopausal women, essentially a cleaner iteration of the MT-II pharmacology.
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No FDA-approved form. Common effects: nausea, flushing, spontaneous erections, facial tingling, hyperpigmentation. Higher side-effect burden than MT-I due to non-selective receptor profile. WADA-prohibited (S4 Hormone class). Not for use in persons with melanoma risk or history. All information educational reference only.