Melanotan II (1 Vial)

Description

Buy Melanotan II at PSPeptides in 10mg lyophilized vials for $39.99, verified at 99%+ HPLC purity with batch-specific Certificates of Analysis from independent third-party laboratories. Melanotan II is a synthetic cyclic heptapeptide analog of α-melanocyte-stimulating hormone (α-MSH), originally developed at the University of Arizona in the late 1980s and characterized in the peer-reviewed literature as a superpotent non-selective agonist across all four melanocortin receptor subtypes.

For adjacent melanocortin research context, see the PT-141 (bremelanotide) product page — the MC3R/MC4R-preferential analog derived from the Melanotan II research program. This product page focuses on what ships, chemical characterization, receptor pharmacology, and quality documentation.

Chemical Identity and Structure

Melanotan II is a 7-amino-acid cyclic peptide with a lactam bridge between the aspartate (position 5) and lysine (position 10) side chains, producing a constrained cyclic scaffold that dramatically enhances metabolic stability and receptor binding affinity compared to linear α-MSH.

• Sequence: Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
• Molecular formula: C50H69N15O9
• Molecular weight: ~1024 Da
• CAS number: 121062-08-6
• Structural class: Cyclic lactam heptapeptide, α-MSH analog

The N-terminal norleucine (Nle) substitution and the D-phenylalanine at position 7 are the key modifications that distinguish Melanotan II from endogenous α-MSH. These modifications resist enzymatic degradation and confer the extended research half-life documented in the primary literature.

Receptor Pharmacology

Melanotan II is a non-selective agonist across the melanocortin receptor family. Understanding the four melanocortin receptors and their tissue distribution is essential for interpreting Melanotan II research data:

The non-selective activation profile is what distinguishes Melanotan II research from selective analogs. Where afamelanotide (MT-I) selectively activates MC1R and PT-141 (bremelanotide) preferentially activates MC3R/MC4R, Melanotan II activates all four receptors simultaneously — enabling research designs that examine cross-receptor pathway interactions and comparative melanocortin pharmacology.

Published Research Literature

The Melanotan II research base spans nearly four decades. Foundational characterization was published by the Hruby laboratory at the University of Arizona: PubMed indexes the cyclic α-MSH analog design literature including the seminal 1989 synthesis papers.

Dorr et al. (1996, published in Archives of Dermatology) reported the first Phase I human pharmacokinetic and pharmacodynamic characterization of Melanotan II. The Hadley and Dorr (2006, Peptides) review consolidated the receptor selectivity, structure-activity relationships, and MC1R-mediated melanogenesis literature. The MC4R knockout research from Cone and colleagues established the appetite and metabolic pathway involvement of MC4R signaling. PubMed catalogs over 200 melanocortin receptor publications referencing Melanotan II across pharmacology, dermatology, and neurological research contexts.

Common melanocortin antagonist tools used in Melanotan II research include SHU9119 (mixed MC3R/MC4R antagonist), HS014 (MC4R-selective antagonist), and agouti-related peptide (AgRP) derivatives. For general compound background, see the Melanotan II compound overview on Wikipedia.

Melanotan II vs Related Melanocortin Compounds

Two of the three compounds derived from the Melanotan II research program have received FDA approval — an unusually strong translational track record for a research peptide class.

Vial Size and Pricing

Melanotan II for sale at PSPeptides ships the same day (orders placed before 2 PM EST), with free UPS 2nd Day Air on domestic orders. Zero processing surcharges on Affirm, Afterpay, Klarna, Apple Pay, Google Pay, or standard cards.

Reconstitution and Storage

Melanotan II ships as lyophilized powder requiring reconstitution with bacteriostatic water ($9.99) before research use. The cyclic lactam structure is more stable than linear peptides but still requires standard peptide handling — the peptide reconstitution research guide covers step-by-step technique. The free reconstitution calculator handles dose math.

Lyophilized Melanotan II research peptide stores best at -20°C for long-term preservation, with 2-8°C acceptable for shorter research windows. Reconstituted solution refrigerated at 2-8°C and used within approximately 4 weeks. The peptide storage guide covers detailed stability protocols.

Verified Quality Standards

Every Melanotan II research peptide batch at PSPeptides ships with third-party HPLC purity verification and mass spectrometry molecular identity confirmation matching the expected 1024 Da molecular weight for the cyclic heptapeptide. Batch-specific Certificates of Analysis from independent laboratories — not in-house verification — accompany every vial. The peptide COA interpretation guide covers vendor documentation standards.

US-based synthesis provides domestic regulatory oversight throughout the manufacturing and QC pipeline. Melanotan II USA 2026 supply from PSPeptides is manufactured domestically in New Jersey with full chain-of-custody documentation from synthesis through final quality control.

Sourcing Considerations

Researchers who buy Melanotan II online from a verified vendor gain access to consistent batch-to-batch purity — critical for reproducible research data in melanocortin receptor pharmacology studies. Impurities in cyclic peptide preparations can arise from incomplete lactam bridge cyclization, epimerization at the D-Phe position, or side-chain oxidation — issues that only third-party analytical verification catches reliably. The research peptide supplier selection guide covers the full vendor vetting checklist.

PSPeptides publishes clear pricing (no hidden fees), same-day processing (including weekends), and 7-day-a-week research support via email at [email protected] or phone at (551) 284-2670. The peptide payment options guide covers the payment infrastructure comparison across the industry.

Frequently Asked Questions

What makes Melanotan II different from α-MSH and other melanocortin analogs?

Melanotan II is a cyclic lactam heptapeptide with two key modifications from α-MSH: N-terminal norleucine (Nle) substitution and D-phenylalanine at position 7. These modifications produce enhanced metabolic stability, higher receptor binding affinity, and non-selective activation across MC1R/MC3R/MC4R/MC5R. Related compounds afamelanotide (MC1R-selective) and PT-141 (MC3R/MC4R-preferential) show narrower selectivity profiles.

What receptors does Melanotan II activate?

All four melanocortin receptor subtypes: MC1R (melanocytes, dermal signaling), MC3R (hypothalamic energy balance), MC4R (appetite and neurological pathways), and MC5R (exocrine gland function). This non-selective activation profile enables research designs examining cross-receptor pathway interactions that selective analogs cannot address.

Where can researchers find Melanotan II for sale with verified COA documentation?

Melanotan II for sale at PSPeptides ships with batch-specific third-party HPLC purity verification and mass spectrometry molecular identity confirmation. Each Certificate of Analysis is generated by an independent laboratory (not in-house), verifies the 1024 Da molecular weight, and confirms the cyclic lactam structure.

Where can researchers buy Melanotan II online with US-based synthesis?

Researchers can buy Melanotan II online at PSPeptides with US-based manufacturing in New Jersey and full chain-of-custody documentation. Same-day processing on domestic orders placed before 2 PM EST, free UPS 2nd Day Air shipping, and zero processing surcharges across all payment methods.

What is the vial size and format?

10mg lyophilized cyclic peptide vial at $39.99. Requires reconstitution with bacteriostatic water before research use. The cyclic lactam structure provides good stability compared to linear peptides but still benefits from proper temperature handling per standard peptide protocols.

All PSPeptides products are sold exclusively for research and laboratory use.