As a structural analog of α-MSH (melanocyte-stimulating hormone), Melanotan-II (MT-II) exhibits properties similar to α-MSH. It acts as a non-selective melanocortin receptor agonist, demonstrating activity at melanocortin receptors MC1R, MC3R, MC4R and MC5R.
Structurally, Melanotan-II is a cyclic heptapeptide (Ac-Nle-cyclo[Asp-His-DPhe-Arg-Trp-Lys]-NH₂). This cyclized architecture affords a shorter peptide chain than the linear MT-I.
Although in vitro studies indicate Melanotan-II exhibits weaker efficacy than Melanotan-I in activating melanocyte MC1R to induce pigmentation, Melanotan-II has been found to possess potential advantages in other aspects, particularly in central nervous system regulation.
Sequence
Ac-{Nle}-Asp-His-{d-Phe}-Arg-Trp-Lys-NH2, (2→7)-lactam
CAS Number
121062-08-6
Molecular Formula
C50H69N15O9
Molecular Weight
1024.18
Research Of Melanotan-II
1.what is melanotan-II
1)Discovery and Development
Melanotan-II is a synthetic melanocortin receptor agonist initially developed for skin cancer protection. However, its unexpected discovery of central nervous system and sexual function regulatory effects has expanded its potential applications across multiple fields.
2) Skin Pigmentation Effects
As an analog of α-MSH, Melanotan-II can activate melanocytes and induce skin tanning. In a single-blind study, three participants received either saline or Melanotan-II via subcutaneous injection once daily on weekdays for two weeks.
Measurements were repeated at the same site on day 21. Visual assessment revealed noticeable facial pigmentation in participants following administration. Evidence indicates that Melanotan-II promotes tanning through its action as an agonist at the MC1R in melanocytes¹.
3)Erectile Dysfunction Treatment
Melanotan-II can treat male erectile dysfunction (ED). In a small cohort of 10 patients with psychogenic ED, subcutaneous injection of the peptide (0.025 mg/kg body weight) was evaluated via real-time monitoring within 6 hours: 8 men achieved clinically meaningful erections².
These findings were later confirmed in a double-blind controlled study³.
4)Metabolic Effects
Animal studies have demonstrated that Melanotan-II suppresses appetite and promotes fat burning. Researchers specifically knocked out the PTP1B(Protein Tyrosine Phosphatase 1B) gene (a negative regulator of leptin signaling) in POMC(Proopiomelanocortin) neurons of mice.
These mutant mice exhibited stronger responses to intracerebroventricular injections of leptin and Melanotan-II (a melanocortin receptor agonist), manifesting as enhanced appetite suppression, weight loss, and thermogenic responses.
Furthermore, this genetic deletion resulted in increased expression of the MC4R receptor in the mice⁴.
2.Conclusion
Melanotan-II, as a non-selective melanocortin receptor agonist, not only shows promise for inducing skin pigmentation but has also garnered significant scientific interest for its potent centrally mediated effects on sexual function regulation, particularly in improving ED.
Its preliminary clinical results in ED treatment are encouraging, and its pleiotropic mechanism of action establishes a promising foundation for the development of novel ED therapeutics.
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