Melanotan II Peptide Pen (MT-2) | 20mg

Melanotan II, also written melanotan 2, MT-2 or MT2, is a synthetic cyclic analogue of α-melanocyte-stimulating hormone, supplied here pre-mixed at 20 mg in a 3 ml stabilised cartridge at a stated 6.67 mg/ml. No lyophilised powder and no reconstitution step. A melanotan 2 pen and an MT2 pen are the same 20 mg pre-mixed cartridge.

What Melanotan II is

α-MSH is a 13-residue melanocortin hormone. Melanotan II is a cyclic heptapeptide built from its active core: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂, 1024.2 g/mol.

Three modifications distinguish it from the native hormone, and each does specific work. It is cyclised through a lactam bridge between the aspartate and lysine side chains, which locks the backbone into the conformation that binds the receptor. The phenylalanine is in the D configuration, which resists proteolysis. And it is truncated to seven residues, discarding the parts of α-MSH that contribute nothing to receptor binding. The result is a constrained, protease-resistant analogue substantially more potent at melanocortin receptors than the hormone it derives from.

It is non-selective across the melanocortin receptor family, with activity at MC1R, MC3R, MC4R and MC5R. That lack of selectivity is central to how it is used in research: the selective analogues that came later are the tools for isolating one receptor, and Melanotan II is the broad-spectrum comparator against which they are measured. The related tripeptide fragment KPV — residues 11 to 13 of α-MSH — appears in KLOW Peptide Pen 160mg.

Melanotan pen: the same thing under a shorter name

Most people searching for this product type “melanotan pen” rather than the full compound name, and the two mean the same thing. A melanotan pen is a pre-filled Melanotan II cartridge in a dial-dosing pen, as opposed to lyophilised powder in a vial.

This pen holds 20 mg in a sealed 3 ml cartridge, at 6.67 mg/ml. The dial is graduated at 15 clicks = 1 mg. Those are device figures — what the mechanism displaces, not what should be dispensed.

Applications in research

• Melanocortin receptor pharmacology. Binding and functional assays across MC1R through MC5R, where a non-selective agonist is required as the reference point for selective compounds.
• Conformational constraint studies. Structure–activity work using the cyclic lactam bridge as the variable, comparing constrained and linear analogues of the same core sequence.
• Melanogenesis assays. Melanin synthesis in cultured melanocyte preparations, with MC1R signalling as the pathway under study.
• Analytical method development. Melanotan II has been the subject of published HPLC and bioassay comparison work for plasma quantification, making it a reference analyte for peptide assay validation.

Legal status in the UK — read this before ordering

This compound warrants a clearer warning than most in the catalogue. Melanotan II is not a licensed medicine in the United Kingdom or in any other territory, and it holds no MHRA marketing authorisation.

The MHRA has issued repeated public warnings against the use of melanotan products sold for tanning, and has taken enforcement action against sellers marketing them for human use. Supplying or advertising an unlicensed medicinal product for human consumption is an offence under the Human Medicines Regulations 2012, and melanotan is one of the compounds the regulator has actively pursued on that basis.

Melanotan II is not a controlled drug under the Misuse of Drugs Act 1971, and buying and possessing it for laboratory research is lawful. It is supplied here strictly as an in-vitro research chemical. It is not supplied for tanning, for cosmetic use, or for administration to any person or animal, and we will not supply it to anyone indicating such a purpose.

What you are actually comparing between listings

• Total mass. This cartridge holds 20 mg. Melanotan II is commonly sold in 10 mg vials, so one unit here carries roughly double a typical listing.
• Format. Pre-mixed solution at a stated 6.67 mg/ml against lyophilised powder requiring bacteriostatic water and a concentration calculation.
• Cost per milligram. At £70 for 20 mg this works out at £3.50 per mg.

Handling and storage

Store at 2–8 °C and protect from light. Keep the cartridge sealed until use, then upright, and observe aseptic technique. Do not freeze. The tryptophan residue is photosensitive, so light exposure matters here more than the peptide's small size would suggest. Orders placed before 2pm are dispatched the same working day, cold-packed, in plain outer packaging.

References

Literature on the molecule. These describe Melanotan II as a compound and none is a claim about this product or an endorsement of any use of it.

1. Dorr RT, Lines R, Levine N, et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996;58(20):1777–84. PMID 8637402.
2. Ugwu SO, Blanchard J, Dorr RT, et al. A comparison of HPLC and bioassay methods for plasma melanotan-II (MT-II) determination. Biopharm Drug Dispos. 1994;15(5):383–90. PMID 7981427.

Research use only

This material is supplied strictly for in-vitro research and analytical purposes. It is not for human or veterinary administration, not for cosmetic or tanning use, and not for any diagnostic or therapeutic application. It holds no marketing authorisation in any territory. Confirm the current regulatory position before drafting institutional documentation, and clear the material through your own ethics, COSHH and biosafety processes before ordering.