Melanotan II functions as a non-selective melanocortin receptor agonist. Its cyclic structure provides enhanced receptor binding affinity and metabolic stability compared to linear α-MSH. Upon binding MC1R on melanocytes, it activates adenylyl cyclase via Gs protein coupling, increasing cAMP levels and stimulating tyrosinase activity to drive melanin synthesis. At MC4R, activation modulates hypothalamic signaling pathways involved in energy balance and autonomic function. The broad receptor profile across MC1R, MC3R, MC4R, and MC5R accounts for the diverse biological effects observed in research settings.
Research Use Only
Melanotan II — Synthetic Alpha-MSH Analog for Melanocortin Research
A synthetic analog of alpha-melanocyte stimulating hormone (α-MSH) studied for its activation of melanocortin receptors (MC1R, MC3R, MC4R, MC5R) in pigmentation, metabolic, and behavioral research.
MelanocortinHair & Skin
CAS 121062-08-6 • 1,024.18 g/mol • Prepared for research use • Per research workflow
Melanotan II Structure
Reference identifiers are batch-specific for coded materials and are documented on the lot COA/SDS rather than inferred or estimated.
Mechanism of Action
Melanotan II Overview
Melanotan II (MT-II) is a cyclic heptapeptide and synthetic analog of alpha-melanocyte stimulating hormone (α-MSH), originally developed at the University of Arizona. As a non-selective melanocortin receptor agonist, MT-II activates multiple receptor subtypes — MC1R, MC3R, MC4R, and MC5R — making it one of the most widely studied peptides in melanocortin biology. Research interest in Melanotan II spans several distinct pathways. Its activation of MC1R, the primary melanocortin receptor expressed in melanocytes, has been extensively studied in the context of melanogenesis and UV-independent pigmentation. MC4R activation has been investigated for its role in sexual function and energy homeostasis, leading to the development of related compounds for clinical applications. MC3R and MC4R engagement has also been explored in appetite regulation and metabolic research, while broader melanocortin signaling is studied for potential anti-inflammatory and neuroprotective properties. Melanotan II remains one of the most referenced peptides in melanocortin receptor research, with hundreds of published studies examining its pharmacology, receptor selectivity, and downstream signaling cascades. PharmaOrder supplies high-purity lyophilized MT-II for research use only, with Certificates of Analysis available and independent third-party verification through Finnrick Analytical. For research use only. Not intended for human consumption.
Purity & Testing
Melanotan II is listed as 10mg lyophilized vial. Catalog identity: CAS 121062-08-6; formula C50H69N15O9; molecular weight 1,024.18 g/mol. The lot COA for Melanotan II is available in your account. Finnrick Analytical performs HPLC purity analysis and mass spectrometry identity confirmation on that lot.
- Catalog configurations: 10mg lyophilized vial
- CAS: 121062-08-6
- Formula: C50H69N15O9
- Molecular weight: 1,024.18 g/mol
See the Melanotan II COA page.
Storage & Handling
Store the lyophilized powder at 2-8°C, protected from light. For in-vitro preparation, use an appropriate laboratory diluent.
Shipping
Ships worldwide from 6 distribution centers via USPS Ground Advantage
Available for direct research purchase
Research-use-only products are sold strictly for laboratory and research purposes. By purchasing, you acknowledge that these products are not intended for human or veterinary use, and you agree to PharmaOrder's RUO terms of service.
Published Research
Selected peer-reviewed studies referenced in this product overview.
Superpotent melanotropin [Nle4-D-Phe7]-alpha-MSH: its biological actions, design, and synthesis
Hruby VJ, Wilkes BC, Hadley ME, et al. — Annals of the New York Academy of Sciences (1993)
Describes the design and synthesis of superpotent melanocortin analogs including Melanotan II and their receptor binding profiles.
A melanocortin receptor agonist produces UV-independent tanning in human skin
Dorr RT, Lines R, Levine N, et al. — Journal of Investigative Dermatology (1996)
First human study demonstrating that Melanotan II induces melanogenesis and skin darkening independent of UV radiation exposure.
Melanocortin receptors: targets for novel drug development
Catania A, Gatti S, Colombo G, Lipton JM. — European Journal of Pharmacology (2004)
Reviews melanocortin receptor pharmacology including MT-II interactions with MC1R through MC5R subtypes and their therapeutic implications.
FAQ
What is Melanotan II?
Melanotan II (MT-II) is a synthetic cyclic heptapeptide analog of alpha-melanocyte stimulating hormone (α-MSH). It is a non-selective agonist of melanocortin receptors MC1R, MC3R, MC4R, and MC5R, and is widely used in research studying pigmentation, metabolic signaling, and melanocortin receptor pharmacology. For research use only.
What melanocortin receptors does MT-II activate?
MT-II is a non-selective melanocortin agonist that activates MC1R (involved in pigmentation and melanogenesis), MC3R and MC4R (involved in energy homeostasis and appetite regulation), and MC5R (involved in exocrine gland function). This broad receptor profile makes it a versatile tool in melanocortin research.
How should Melanotan II be stored?
Store the lyophilized powder at 2-8 degrees C, protected from light; bring to room temperature before opening. For in-vitro preparation, use an appropriate laboratory diluent. Avoid repeated freeze-thaw cycles to maintain peptide integrity. For research use only.
How does Melanotan II differ from PT-141?
Both peptides are synthetic melanocortin analogs, but PT-141 (bremelanotide) was derived from Melanotan II research and is a more selective MC4R agonist. MT-II activates a broader range of melanocortin receptors (MC1R, MC3R, MC4R, MC5R), making it more useful for general melanocortin pathway research, while PT-141 is studied primarily for MC4R-mediated effects.
Editorial Review
Updated March 2026. Reviewed against product catalog, quality, and fulfillment standards. This page is educational and not instructions for human use. See our editorial standards and quality process.
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