Melanotan-II (MT2) 10mg

Compound Name: Melanotan-2

Synonyms: Melanotan-II, MT-II

CAS Number: 121062-08-6

Molecular Formula: C₅₀H₆₉N₁₅O₉

Molecular Weight: ~1024.2 g/mol

Structure: Cyclic heptapeptide analog

Peptide Sequence: Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂

Chemical Structure:

Source: PubChem

Mechanism of Action: Melanotan-II is a potent nonselective agonist of melanocortin receptors, especially MC1, MC3, MC4, and MC5. By binding these G-protein-coupled receptors, melanotan-II stimulates cAMP signaling. MC1 activation promotes skin melanogenesis, resulting in increased eumelanin synthesis and tanning. MC3 and MC4 receptor activation in the central nervous system and spinal cord modulate sexual arousal, induce spontaneous erections, and affect energy homeostasis. MC4 activation, in particular, is associated with enhanced sexual behavior in both males and females, as well as modulation of sympathetic nervous system output. MC5 receptor agonism may influence exocrine gland function and thermoregulation^1-3.

Biological Activity: Melanotan-II increases skin pigmentation by inducing melanin production, promotes penile erections and sexual arousal, and, in animal models, demonstrates neuroprotective and neurotrophic effects, such as improved peripheral nerve regeneration and protection against chemotherapy-induced neuropathy. At research doses in rats, it enhances both the induction and facilitation of penile erection via central and peripheral melanocortin pathways, modulates female sexual proceptivity, and supports sensory recovery after nerve injury^1-4.

Storage: Store lyophilized peptide at -20°C; reconstituted solutions should be aliquoted and stored at -20°C. Avoid repeated freeze-thaw cycles.

Drug Categories: Melanocortin receptor agonists, tanning agents (investigational), sexual dysfunction research tools, peptide research reagents.

Additional Notes: For research use only; Not approved for clinical use.

Summary Table:

Disclaimer: For Research Use Only. Not intended for human or veterinary use. This compound is supplied solely for laboratory and R&D purposes.

Detailed Product Description

Melanotan-II (MT-II) is a synthetic cyclic heptapeptide and potent, nonselective agonist of melanocortin receptors—most notably MC1, MC3, MC4, and MC5. Originally designed as a more stable and bioavailable analog of α-melanocyte stimulating hormone (α-MSH), Melanotan-II acts as a robust stimulator of melanogenesis, resulting in significant skin darkening when administered in research models through MC1 activation. Its cyclic structure confers substantial resistance to enzymatic degradation, allowing for prolonged receptor activity both in vitro and in vivo. In addition to its melanogenic effects, MT-II has become a critical research reagent for investigating the role of central melanocortin signaling in sexual function. It potently stimulates sexual arousal and spontaneous penile erection in male rodents and enhances proceptive sexual behaviors in hormonally primed females via CNS-mediated MC3 and MC4 receptor pathways.

Beyond its established effects on pigmentation and sexual behavior, Melanotan-II demonstrates neuroprotective and neurotrophic actions, supporting peripheral nerve regeneration and providing protection against experimentally induced neuropathies. These effects are believed to be mediated predominantly via MC4 receptor signaling. It also influences exocrine glandular function and thermoregulation through MC5 activation. MT-II is supplied as a lyophilized powder for reconstitution, intended strictly for laboratory research and not for human or veterinary use.

Research Highlights

• Promotes skin tanning: Induces potent melanogenesis via MC1 receptor agonism, resulting in increased eumelanin content¹.
• Sexual function: Enhances erectile activity and proceptive sexual behaviors in male and female rodents via MC3/MC4 activation².
• Neuroprotection: Facilitates sensory recovery after peripheral nerve injury and protects against cisplatin-induced neuropathy in rats³.

• Central & peripheral action: Elicits both inducer and facilitator effects on sexual function through actions at the hypothalamus, spinal cord, and peripheral nerves³.

Mechanism of Action

MC1 Receptor (Melanocortin 1 Receptor)

• Stimulates melanogenesis: Activation of MC1 on skin melanocytes increases cAMP and activates tyrosinase, resulting in enhanced eumelanin (dark pigment) synthesis and visible skin darkening (tanning)¹.
• Photoprotection: Increased melanin can enhance resistance to UV-induced skin damage and reduce phototoxicity; this property underlies its investigational use in rare photodermatoses²..
• Pigmentary changes: Can lead to rapid and noticeable changes in existing moles or nevi, with possible cosmetic or dermatologic implications².

MC3 (Melanocortin 3) Receptor Agonism

• Regulates sexual behavior (CNS): MC3 activation in the hypothalamus and other brain regions modulates appetite and mediates aspects of sexual arousal and proceptive sexual behavior, such as solicitation and increased sexual motivation in animals^1-3.
• Energy homeostasis: May participate in central appetite and metabolic regulation, though MT-II’s sexual and behavioral effects are most prominent and well-documented via MC3¹.
• Synergy with hormonal priming: Effects on sexual proceptivity are particularly pronounced when combined with estradiol and progesterone priming in female models².

MC4 (Melanocortin 4) Receptor Agonism

• Enhances sexual arousal and erections: MC4 activation centrally (in hypothalamus/spinal cord) and peripherally increases sexual motivation and induces penile erection in males and facilitates proceptive sexual behaviors in both sexes^2-4.
• Facilitates sympathetic outflow: Modulates autonomic functions by increasing sympathetic nervous system tone, which can affect cardiovascular responses, energy expenditure, and possibly explain sympathomimetic side effects^3,4.
• Neuroprotective and neurotrophic actions: MC4 signaling is implicated in the regeneration and protection of peripheral nerves, as observed in experimental injury and neuropathy models³.

MC5 (Melanocortin 5) Receptor Agonism

• Stimulates exocrine secretion: MC5 activation promotes secretion by exocrine glands, influencing tear and sweat production and other peripheral gland functions².
• Thermoregulation: Plays a role in body temperature regulation and the stress response, with effects noted on the hypothalamic-pituitary-adrenal axis³.
• Peripheral modulation: Actions are more pronounced in peripheral tissues than in CNS; the physiological impact is less central than MC3/MC4 but can contribute to overall systemic effects⁴.

Pharmacokinetic Profile:

• Route of Administration: Subcutaneous/intravenous (research)
• Dosing Frequency: Once daily
• Half-Life: Varies depending on experimental design; not approved for human use—refer to research protocols
• Formulation: Lyophilized powder for reconstitution

Formulation & Handling

• Lyophilized powder, reconstituted in sterile saline.
• Store lyophilized powder at –20 °C.

Selected Clinical Trial Activity

Melanotan-2 is a research-grade compound that has been studied in laboratory settings but has not undergone full clinical development. It is not approved for therapeutic use in humans, and no large-scale clinical trials have been conducted to evaluate its safety or efficacy as a medication. Melanotan-2 is supplied strictly for laboratory research and investigational purposes only.

References

¹Al-Obeidi, F. et al. Design and synthesis of superpotent and superactive analogues of alpha-melanotropin. J. Med. Chem. 32, 2555–2561 (1989).

²Giuliano, F. et al. Melanotan-II: Investigation of the inducer and facilitator effects on penile erection in anaesthetized rat. Neuroscience 138, 293–301 (2006).

³Ter Laak, M. P. et al. The potent melanocortin receptor agonist melanotan-II promotes peripheral nerve regeneration and has neuroprotective properties in the rat. Eur. J. Pharmacol. 462, 179–183 (2003).

⁴Rössler, A-S. et al. The melanocortin agonist, melanotan II, enhances proceptive sexual behaviors in the female rat. Pharmacol. Biochem. Behav. 85, 514–521 (2006).