Melanotan‑II (MT‑2) Peptide Profile
Overview:
Melanotan‑II (MT‑2) is a synthetic cyclic peptide analogue of α‑melanocyte‑stimulating hormone (α‑MSH) that activates multiple melanocortin receptors (MC1R, MC3R, MC4R, MC5R) to induce effects on melanin production (skin pigmentation), appetite, sexual function, and energy homeostasis. MT‑2 was originally synthesized in the 1990s at the University of Arizona as a potential sunless tanning agent and for sexual dysfunction research, but development was discontinued and it never gained regulatory approval for therapeutic use; unlicensed products are widely sold online despite safety warnings from multiple health authorities. (Wikipedia)
Mechanism of Action:
MT‑2 mimics the body’s natural α‑MSH by binding melanocortin receptors:
• MC1R: stimulates melanocytes to increase melanin synthesis, leading to darker skin pigmentation (sunless tan). (Wikipedia)
• MC4R (and MC3R): affects appetite suppression and energy balance. (PMC)
• MC4R/central pathways: may elicit sexual arousal effects, including spontaneous erections reported in early studies. (Wikipedia)
Effects & Reported Uses (Informational, Not Approved):
• Skin pigmentation/tanning: tanning effects observed with low‑dose subcutaneous injections in research settings. (PubMed)
• Appetite suppression and weight modulation: MT‑2 reduces food intake in animal models via central melanocortin pathways. (PMC)
• Sexual function: early research linked MT‑2 with spontaneous penile erections; this effect inspired development of related compound bremelanotide, an approved drug for female sexual dysfunction derived from MT‑2’s structure. (Wikipedia)
Safety & Risks:
MT‑2 products are unregulated, unapproved, and potentially unsafe. Side effects reported include nausea, flushing, vomiting, appetite reduction, yawning, spontaneous erections, and more serious concerns such as increased moles, darkening of existing moles, potential melanoma risk, kidney dysfunction, rhabdomyolysis, and neurological effects. Health authorities in multiple countries warn against use. (Therapeutic Goods Administration (TGA))
Experimental / Community Dosing (Not Approved):
| Use Context | Typical Dose | Frequency | Route | Notes |
| Research observation (tanning) | ~0.025 mg/kg | Every other day | Subcutaneous | Pilot human study in research setting (RxList)
| Erectile effect observation | ~0.025 mg/kg | Single or repeat | Subcutaneous | Based on early clinical research (RxList)
References (APA):
Melanotan II. (n.d.). Wikipedia. https://en.wikipedia.org/wiki/Melanotan_II (Wikipedia)
What is Melanotan‑II — the drug that the TGA urges consumers to avoid. (2023, Jan 30). UNSW. https://www.unsw.edu.au/newsroom/news/2023/01/what-is-melanotan-ii—the-drug-that-the-tga-urges-consumers-to‑ (unsw.edu.au)
Melanotan II. (n.d.). DermNet NZ. https://dermnetnz.org/topics/melanotan-ii (DermNet®)
Evaluation of melanotan‑II, a superpotent cyclic melanotropic peptide in humans. (1996). PubMed. https://pubmed.ncbi.nlm.nih.gov/8637402/ (PubMed)
Advice on the use of injecting tanning agents like Melanotan. (n.d.). Drugs.ie. https://www.drugs.ie/news/article/advice_on_the_use_on_injecting_tanning_agents_melanotan (drugs.ie)
Tanning, fake tan and Melanotan injections. (n.d.). Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/sun-uv-and-cancer/fake-tan-and-melanotan-injections (Cancer Research UK)
