What is Melanotan II?

Melanotan II is a synthetic, cyclic peptide modelled on alpha-melanocyte-stimulating hormone (α-MSH), the signal your body uses to switch on melanin production. It keeps only the core seven residues of the natural hormone and closes them into a ring with a lactam bridge, which makes it more potent and longer-acting at melanocortin receptors than α-MSH itself Dorr RT et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci 1996. PMID 8637402. The pigmentation effect runs through the melanocortin-1 receptor (MC1R) on melanocytes, the receptor that governs melanin synthesis in human skin Böhm M et al. An overview of benefits and risks of chronic melanocortin-1 receptor activation. J Eur Acad Dermatol Venereol 2025. PMID 39082868. Melanotan II does not stop there: it is a non-selective melanocortin agonist Peters B et al. Melanotan II: a possible cause of renal infarction: review of the literature and case report. CEN Case Rep 2020. PMID 31953620, and that breadth is the single biggest difference from its selective relative, which we set side by side on Melanotan II vs Melanotan I.

Most of what is published about melanotan II is receptor pharmacology rather than medicine. A 2024 review of the melanocortin receptor family lists it, with melanotan I and SHU9119, among the synthetic α-MSH derivatives used as tool compounds: reference ligands for characterising the five receptor subtypes, validating receptor-expressing cell lines and anchoring cryo-electron-microscopy structures, and scaffolds for approved melanocortin medicines Weirath NA, Haskell-Luevano C. Recommended Tool Compounds for the Melanocortin Receptor (MCR) G Protein-Coupled Receptors (GPCRs). ACS Pharmacol Transl Sci 2024. PMID 39296259. That is its role in the literature: a reference ligand, not a medicine that has been through development.

The human studies are few, small and decades old. The pilot phase I study by Dorr and colleagues gave it to three healthy men on alternating days with saline: they reported mild nausea and a stretching-and-yawning complex that coincided with spontaneous erections lasting one to five hours, and two of the three showed increased pigmentation a week after dosing ended Dorr RT et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci 1996. PMID 8637402. A double-blind crossover study in ten men with psychogenic erectile dysfunction recorded erections in eight of the ten after melanotan II, with nausea, stretching and yawning and reduced appetite reported more often than after placebo Wessells H et al. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. J Urol 1998. PMID 9679884. Those sexual effects follow from the receptor profile, not from an impurity: work in mice and human tissue showed that the melanocortin-4 receptor (MC4R), also implicated in food intake, modulates erectile function and sexual behaviour, and is expressed in nerve fibres of the human penis and in spinal erectile pathways Van der Ploeg LH et al. A role for the melanocortin 4 receptor in sexual function. Proc Natl Acad Sci U S A 2002. PMID 12172010.

On status, one statement covers it: no melanotan II product holds a marketing authorisation in the European Union. The melanocortin agonist that does, afamelanotide (Scenesse), is a different molecule, authorised in December 2014 under exceptional circumstances as an implant renewed every two months for erythropoietic protoporphyria, a rare disease that causes intolerance to light European Medicines Agency. Scenesse (afamelanotide): European public assessment report.. In the United Kingdom the MHRA treats a product containing melanotan II as a medicine when it meets the legal definition of one, and a medicine must be authorised to be sold; it says it has repeatedly removed such melanotan products from sale for over ten years, and that it received 13 suspected adverse-reaction reports for melanotan II between 2011 and 2021, which it notes do not by themselves show the drug caused the events Medicines and Healthcare products Regulatory Agency. FOI 21/1237: Yellow Card reports for melanotan II products, 2011–2021. 2021.. Other national health authorities have issued safety warnings about melanotan I and II Habbema L et al. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. Int J Dermatol 2017. PMID 28266027. Why none of the peptides we supply is EMA-authorised is explained at why these compounds are not EMA-authorised.

The recent human record is case reports, and they describe timing, not rates. A 2026 report followed a patient who self-injected melanotan II for 64 days and developed brown pigmentation of the gums in both jaws and irregular patches inside both cheeks; the cheek pigmentation had almost gone one month after stopping, the gum pigmentation was fainter but still present at three months, and the author notes that no published data describe how long such changes take to resolve Bonchev A. Changes in Oral Mucosa Associated with Melanotan II Injections: A Case Report. Life (Basel) 2026. PMID 41752902. A 2025 report describes a 22-year-old woman who had used a melanotan II nasal spray and was diagnosed with mucosal malignant melanoma of the upper jaw; the authors raise the spray as a possible risk factor Yassin Alsabbagh A et al. Melanotan II nasal spray: a possible risk factor for oral mucosal malignant melanoma? Int J Oral Maxillofac Surg 2025. PMID 40210573. One patient's timeline cannot establish causation either way; what the reports establish is that the events were observed and written up. Because MC1R signalling acts on the cell type melanoma arises from, and the review by Böhm and colleagues above is explicit that MC1R activation does not prevent melanoma in people with risk factors, any change to an existing mole warrants prompt medical assessment.

What we supply is MELANOTAN II 20: 20 mg of melanotan II already in solution in a 3 ml pre-loaded multi-dose pen, in stock and shipping now, listed with GHK-Cu under peptides for skin. Every batch is tested by an independent lab for identity by mass spectrometry, purity by HPLC and sterility; identity is confirmed by mass rather than by a chromatographic retention time alone, which ICH Q6A does not regard as a specific identity test ICH Q6A. Specifications: test procedures and acceptance criteria for new drug substances and new drug products. 1999.. The certificate for your batch shows HPLC purity and cartridge concentration (mg/ml and total mg per 3 ml); reach it by scanning the QR code on the pen or from the certificate index. The other peptide on the skin page has its own explainer at what is GHK-Cu?.