Description

Melanotan-2 – Prometheus Labs Research Peptide

Melanotan-2 is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (alpha-MSH), developed through structural modification of the native hormone to improve metabolic stability and receptor binding affinity. Its primary research significance lies in its broad melanocortin receptor agonism, engaging MC1R, MC3R, MC4R, and MC5R, making it a versatile tool across pigmentation biology, neuroendocrine, and appetite regulation research models.

Prometheus Labs provides Melanotan-2 at 10mg per vial, 99+% purity confirmed by batch-specific HPLC and Mass Spectrometry analysis, as a lyophilized compound for use in controlled laboratory settings.

Molecular Profile and Chemical Specifications

Primary Research Mechanisms

Melanotan-2 is investigated across four interconnected melanocortin receptor pathways. Each represents an active and distinct area of preclinical research.

MC1R Activation and Melanogenesis

Melanotan-2 activates the MC1R receptor on melanocytes, triggering Gs-coupled adenylyl cyclase activity and elevating intracellular cAMP. This drives transcriptional upregulation of the melanogenic enzyme cascade, tyrosinase, TRP-1, and TRP-2, resulting in increased eumelanin synthesis. Pigmentation biology research uses this pathway to investigate the molecular regulation of skin and hair colour in experimental models.

MC4R Activation and Hypothalamic Appetite Regulation

MC4R is expressed in hypothalamic nuclei governing energy homeostasis, including the paraventricular nucleus and arcuate nucleus. Melanotan-2’s MC4R agonism is studied in appetite regulation research as a tool for examining central melanocortin contributions to feeding behaviour and energy balance in rodent models, independently of its peripheral pigmentation activity.

MC3R and MC4R Activation in Sexual Function Research

Melanotan-2 engages both MC3R and MC4R in limbic and hypothalamic regions associated with autonomic arousal pathways. Research in this area examines centrally mediated effects on sexual function signalling, providing a mechanistic basis that is distinct from peripherally acting approaches. This is the same receptor profile studied in PT-141 (Bremelanotide) research, with Melanotan-2’s additional MC1R activity representing the primary structural distinction.

MC5R and Exocrine Gland Research

MC5R is expressed in exocrine glands, including sebaceous, lacrimal, and preputial glands. Melanotan-2’s MC5R agonism is studied in the context of exocrine secretion regulation, a less characterized but active research area within the broader melanocortin receptor biology field.

Structural Basis for Metabolic Stability

The cyclic structure of Melanotan-2 is achieved through a lactam bridge between the Asp and Lys side chains, constraining the peptide into a conformation that confers two key research advantages over linear alpha-MSH analogues. First, cyclization provides resistance to proteolytic degradation, extending the experimental window in cell culture and in vivo models. Second, the constrained conformation enhances melanocortin receptor binding affinity relative to the native linear peptide. The D-Phe substitution at position 4 further contributes to enzymatic stability by resisting cleavage at that residue.

Reconstitution Protocol

• Reconstitute using sterile bacteriostatic water or 0.9% sodium chloride solution
• Introduce diluent slowly along the interior vial wall, do not inject directly onto the lyophilized cake
• Swirl gently until fully dissolved, do not shake or vortex
• Allow the vial to equilibrate to room temperature before opening to prevent condensation

Storage and Stability

Store in a desiccated environment away from UV exposure. Avoid repeated freeze-thaw cycles, which degrade peptide chain integrity over time.

Melanotan-2 Research FAQ

Q: How does the cyclic structure of Melanotan-2 differ from native alpha-MSH?

A: Native alpha-MSH is a linear tridecapeptide (13 amino acids). Melanotan-2 is a cyclic heptapeptide incorporating a lactam bridge, a D-Phe substitution, and an N-terminal norleucine modification. These structural changes collectively improve receptor binding affinity, extend metabolic stability, and reduce the sequence to the minimal pharmacophore required for full melanocortin receptor agonism, making it a more experimentally controllable research compound than the native hormone.

Q: What is the relationship between Melanotan-2 and PT-141?

A: PT-141 (Bremelanotide) is a direct metabolite of Melanotan-2, formed by hydrolysis of the N-terminal acetyl group. PT-141 retains MC3R and MC4R agonism but has reduced MC1R activity relative to Melanotan-2. Research comparing both compounds allows investigation of the specific contribution of MC1R-mediated pigmentation signalling versus the central MC3R/MC4R pathways in the same experimental framework.

Q: What purity standard does Prometheus Labs apply to Melanotan-2?

A: Every batch is verified at 99+% purity using HPLC to confirm compound concentration and Mass Spectrometry to confirm molecular identity. Batch-specific COA documentation is available upon request.

Q: Where does Prometheus Labs ship from?

A: All Prometheus Labs products are fulfilled domestically from within Canada, eliminating customs clearance risk and reducing transit time compared to international suppliers.

Q: Is Melanotan-2 for human use?

A: No. Melanotan-2 supplied by Prometheus Labs is strictly for laboratory research purposes. It is not approved for human consumption, veterinary use, or clinical application.