Melanotan II
Melanocortin receptor agonist · α-MSH analog
A cyclic heptapeptide analog of α-melanocyte-stimulating hormone (α-MSH). One of the most studied compounds in melanogenesis and pigmentation research.
Sizes
- 10mg / vial — $60
Specifications
- CAS number: 121062-08-6
- Molecular formula: C50H69N15O9
- Molecular weight: 1024.18 g/mol
- Sequence: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
- Form: Lyophilised powder
- Storage: −20°C, protected from light
What it is
Melanotan II is a shortened, cyclised analog of α-MSH, the endogenous hormone that signals melanocytes. The lactam-bridged ring makes it far more resistant to enzymatic breakdown than the natural hormone, and the D-phenylalanine substitution increases receptor binding — together they turn a fragile thirteen-residue hormone into a stable seven-residue research tool.
Background
Melanotan II is a cyclic analog of alpha-melanocyte-stimulating hormone developed at the University of Arizona in the 1980s. It has never been approved as a medicine in any country.
How it works
It is a non-selective agonist across the melanocortin receptor family — MC1R on melanocytes (the pigmentation pathway that dominates the literature), plus MC3R, MC4R and MC5R, which is why the research base also spans appetite signalling and energy-balance models.
Why researchers order it
The melanocortin system is one of the cleaner model systems in peptide research: receptor distribution is well mapped, and MC1R activation produces a measurable, visible endpoint (melanin synthesis) in cell culture. Melanotan II is the reference agonist most of that literature is built on.
Studied in
- MC1R activation and melanogenesis assays
- Melanocortin receptor selectivity studies
- Appetite and energy-balance signalling models
Handling and storage
Add 2ml of bacteriostatic water for 5mg/ml. Swirl to dissolve — never shake. Store unopened vials at −20°C, protected from light; lyophilised powder is stable for years that way and tolerates shipping at ambient temperature. Solutions prepared for analysis should be held at 2–8°C, protected from light.
Stability notes for this sequence
- The sequence contains tryptophan, which is light-sensitive. Store solutions in the dark.
- Lyophilised powder is stable for years at −20°C in the dark and tolerates days at ambient temperature in transit.
Specification in brief
Melanotan II is a cyclic peptide with the molecular formula C50H69N15O9 and a molecular weight of 1024.18 g/mol, CAS registry number 121062-08-6. The vial is sealed and lot-numbered, holds lyophilised powder, and is kept at −20°C protected from light until it ships.
Sizes and price
Melanotan II is sold per vial in one size: 10mg at $60. Any quantity can be ordered from a single vial upward; ten vials make a sealed box. Shipping is a flat $10 within the United States and free on orders of $250 or more.
Evidence at a glance
The 2 papers cited below are 1 study in humans and 1 review.
Also in Peptide Blends
- BPC-157 + TB-500 — BPC-157 + TB-500 · 1:1 blend
- GHK-Cu — Copper Peptide · Copper tripeptide-1
- GHK-Cu + BPC-157 + TB-500 + KPV — BPC-157 + TB-500 + GHK-Cu + KPV
Further reading
- Melanocortin peptides: Melanotan II and KPV
- How to read a certificate of analysis
- Lyophilised peptide storage and stability
- Reconstitution concentration calculator
Certificate of analysis
Lot CS-mn210-0327, assayed at 99.888%, tested 09 Apr 2026 by Janoshik.
View the certificate for lot CS-mn210-0327 — verification key KLTZIS7JWEJW, checkable at janoshik.com/verify
References
- Hadley ME & Dorr RT (2006). Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization. Peptides. PubMed 16412534 · SummaryHistory of melanocortin peptide development from the α-MSH analogues to clinical candidates.
- Wessells H et al. (1998). Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. J Urol. PubMed 9679884 · SummaryDouble-blind placebo-controlled crossover in men with psychogenic erectile dysfunction: the peptide initiated erections in most subjects, with nausea and flushing as side effects.
Questions about Melanotan II
Is Melanotan II for human use?
No. Everything Zyrna Research supplies is for laboratory research only. It is not for human or veterinary use, and nothing on this page is a claim of safety or efficacy.
Is there a certificate of analysis for Melanotan II?
Yes. The manufacturer's certificate for lot CS-mn210-0327 is shown on this page and reports 99.888% purity. We do not run our own assays; the figure is the manufacturer's, not independent verification.
What sizes does Melanotan II come in?
10mg. Vials ship in the manufacturer's sealed, lot-numbered packaging; nothing is repackaged or relabelled.
How should Melanotan II be stored?
Unopened lyophilised vials at −20°C, protected from light. Prepared solutions at 2–8°C. Repeated freeze–thaw cycles compromise sample integrity for analytical work.
How is it shipped?
From Nashville, Monday to Friday, with carrier tracking on every order. Paid orders are handed to the carrier the next business day; domestic transit is typically 2–4 business days. Lyophilised material is shelf-stable in transit and ships at room temperature.
What if a vial arrives damaged?
Photograph it before opening anything else and email orders@zyrnaresearch.com within 72 hours of delivery. We replace it. Opened or unsealed vials cannot be returned, because storage conditions cannot be verified once they leave our control.
For laboratory research use only. Not for human or veterinary use. Nothing on this page is a claim of safety or efficacy, and none of it has been evaluated by the FDA.