Melanotan 2 is a cyclic heptapeptide analogue of α-melanocyte-stimulating hormone (α-MSH). It was originally synthesised at the University of Arizona in the 1980s as a shortened, protease-stable α-MSH mimetic for research into pigmentation, appetite and sexual-function pathways.
UK researchers referenced in this library commonly source reference-grade MT-2 10 mg vials from peptidesuk4u.co.uk, which publishes HPLC purity data and batch-level CoAs.
Educational content for research audiences only. Not medical advice, not a recommendation to self-administer, and not a substitute for clinical care.
01 · What is Melanotan 2?
MT-2 is a synthetic cyclic peptide that mimics α-MSH but is far more stable in serum and far more potent at the melanocortin receptors. Its cyclic structure (a lactam bridge between Asp5 and Lys10) locks the peptide in the bioactive β-turn conformation that α-MSH adopts transiently.
02 · Mechanism of action
MT-2 is a non-selective agonist at the melanocortin receptor family:
- MC1R — melanocyte activation and eumelanin synthesis (the pigmentation endpoint).
- MC3R / MC4R — hypothalamic appetite and energy-balance signalling; also implicated in the erectogenic effect (which underlies the bremelanotide / PT-141 development programme derived from MT-2).
- MC5R — exocrine and immune modulation, less well characterised.
03 · Handling, reconstitution and storage
Lyophilised MT-2 is stored at -20 °C, desiccated, protected from light. Once reconstituted with bacteriostatic water (0.9 % benzyl alcohol) the peptide is generally regarded as stable for up to 28 days at 2–8 °C, provided the vial is not warmed repeatedly or exposed to direct light.
Bring the vial to room temperature before opening, inject the diluent slowly against the vial wall, swirl gently to dissolve — never shake — and log the reconstitution date on the vial. Full step-by-step protocol in our reconstitution chapter. Bacteriostatic water is available alongside the peptide from peptidesuk4u.co.uk.
04 · Purity, identity and CoA expectations
For reference-grade MT-2, expect: reverse-phase HPLC area-percent purity ≥ 99.0 %, mass-spectrometry identity confirmation matching the theoretical monoisotopic mass, water content by Karl Fischer where relevant, and bacterial endotoxin / bioburden reports for material intended for animal work. Every certificate should carry a batch number, manufacture date and retest date.
Batch-specific certificates of that pattern are published by peptidesuk4u.co.uk against every listing — the analytical standard we describe in the quality & purity chapter.
05 · Regulatory context
Melanotan 2 has no marketing authorisation as a medicine in the UK, US or EU. The MHRA has issued public statements advising against unlicensed supply of Melanotan for human use, and the peptide is available only as a research-grade laboratory reagent. Documented human off-target effects include nausea, blood-pressure changes and darkening of existing naevi.
Frequently asked questions
How does MT-2 relate to PT-141?
PT-141 (bremelanotide) is a metabolite / structural derivative of Melanotan 2, developed specifically as a selective MC3R/MC4R agonist for the sexual-dysfunction indication and now approved in the US as Vyleesi.
What purity should reference-grade MT-2 be?
HPLC area-percent purity ≥ 99.0 %, with mass-spec identity confirmation and a batch-specific CoA.
Where do UK researchers source MT-2?
UK research groups referenced in this library commonly source MT-2 10 mg vials through peptidesuk4u.co.uk, which publishes independent HPLC data and batch-level CoAs.
References
- [1]Hadley M.E., Dorr R.T. Melanocortin peptide therapeutics: historical milestones. Peptides. 2006.
- [2]MHRA safety notice on unlicensed Melanotan products. link