Melanotan 2

MT-2 · MT-II

Rank#999
Skin & HairNot ApprovedPhase IIResearchSubQ

Popular for:Tanning, sexual function, appetite suppression

3

Total Studies

0

Human Studies

Phase II

Evidence Level

Not Approved

FDA Status

Overview

Melanotan II (MT-II) is a synthetic cyclic heptapeptide analogue of α-melanocyte-stimulating hormone (α-MSH). Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂, with a molecular weight of 1024.18 Da. Developed at the University of Arizona in the 1990s as a potential sunless tanning agent, MT-II acts as a non-selective agonist of melanocortin receptors MC1, MC3, MC4, and MC5.

Mechanism of Action

MC1 receptor activation stimulates melanogenesis (skin darkening). MC4 receptor activation mediates sexual arousal and erectile function. MC4 also mediates appetite suppression. MC3 may contribute to sexual effects. The peptide crosses the blood-brain barrier, explaining its central nervous system effects including nausea, yawning, and spontaneous erections.

Key Research Benefits

Skin tanning without UV exposure: MC1 activation increases eumelanin production. Phase I clinical study (Dorr et al., 1996, Life Sciences) confirmed dose-dependent tanning.
Erectile function: Double-blind, placebo-controlled crossover study (Wessells et al., 1998, J Urol) showed MT-II initiated erections in men with psychogenic ED at 0.025 mg/kg.
Appetite suppression: MC4 receptor activation reduces appetite. Some users report reduced caloric intake during loading phase.
Female sexual dysfunction: Bremelanotide (PT-141), derived from MT-II, was FDA-approved in 2019 as Vyleesi for hypoactive sexual desire disorder, validating the MC4-mediated mechanism.

Clinical Evidence Summary

Research Pipeline

Preclinical
Animal
Phase I
Phase II
Phase III
Approved

3

Total Studies

0

Human Studies

- Dorr et al. (1996) — Phase I clinical study evaluating MT-II as a tanning agent. Demonstrated dose-dependent melanogenesis with manageable side effects (Life Sciences, PMID: 8637402).

- Wessells et al. (1998) — Double-blind, placebo-controlled crossover study. MT-II at 0.025 mg/kg initiated erections in men with psychogenic erectile dysfunction (Journal of Urology, PMID: 9679884).

- Javed & Kamraan (2013) — Review of melanoma risk. Found no conclusive evidence that MT-II directly causes melanoma.

- Wensink et al. (2021) — Systematic review concluded increased melanoma risk in MT-II users is more likely explained by concurrent UV exposure behavior.

- Bremelanotide (PT-141), a derivative of MT-II, received FDA approval in 2019 as Vyleesi for HSDD, validating the melanocortin-based mechanism for sexual function.

Key Studies / PubMed References

CAPS2 deficiency induces proopiomelanocortin accumulation in pituitary and affects food intake behavior in mice.

Animal Study

Fujima S, Amemiya N, Arima T, et al. · Neuroscience letters · 2020

PMID: 32891671

Disruption of Gpr45 causes reduced hypothalamic POMC expression and obesity.

Animal Study

Cui J, Ding Y, Chen S, et al. · The Journal of clinical investigation · 2016

PMID: 27500489

Sim1 haploinsufficiency impairs melanocortin-mediated anorexia and activation of paraventricular nucleus neurons.

Animal Study

Kublaoui BM, Holder JL, Gemelli T, et al. · Molecular endocrinology (Baltimore, Md.) · 2006

PMID: 16728530

Side Effects & Safety

> MT-II causes darkening of existing moles and nevi. Monitor all moles closely. Any asymmetry, border changes, or rapid growth warrants immediate dermatological evaluation. The relationship between MT-II and melanoma is unclear — a 2021 review concluded increased melanoma risk in users is likely from concurrent UV exposure rather than the peptide itself.

Common: Nausea (especially at higher doses), facial flushing, fatigue, injection site redness, spontaneous erections, yawning/stretching
Serious/Rare: Rhabdomyolysis (case report at 6mg dose), priapism, darkening of moles/nevi, new nevi formation, elevated blood pressure
Contraindications: History of melanoma or atypical moles, cardiovascular disease, priapism risk factors, pregnancy

Known Interactions

No curated interaction entry is live for Melanotan 2 yet.

Until the interaction table is fully populated, use the interaction checker and related peptides below to explore adjacent compounds and likely research pairings.

Frequently Asked Questions

Research Disclaimer

This page is for research and educational purposes only. The information presented is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. Melanotan 2 is not approved by the FDA for human therapeutic use. Always consult a qualified healthcare professional before making any health-related decisions. The studies referenced are linked to their original PubMed sources for verification.