What Is Melanotan 2?
Melanotan 2 (MT-2) is a synthetic analogue of alpha-melanocyte-stimulating hormone (α-MSH), a cyclic heptapeptide developed at the University of Arizona in the 1980s and 1990s as part of a research program investigating photoprotective compounds. It acts as a potent, non-selective agonist at melanocortin receptors MC1R, MC3R, MC4R, and MC5R — with higher potency and substantially greater metabolic stability than native α-MSH, which has a plasma half-life of only minutes. MT-2’s cyclization and structural modifications contribute to a half-life measured in hours to days.
MT-2’s broad melanocortin receptor activity profile has made it a research tool across several distinct biological domains: skin pigmentation biology (MC1R), sexual function research (MC4R — which led to the development of FDA-approved Bremelanotide/PT-141), appetite and energy homeostasis (MC3R/MC4R), and inflammation research (MC1R/MC3R).
Melanotan 2 Mechanism of Action
- MC1R (melanocytes): Stimulates melanin synthesis and transfer in melanocytes, producing eumelanin (dark pigment) accumulation. This was the original research target — investigating whether pharmacological tanning could reduce UV-induced DNA damage and skin cancer risk
- MC4R (hypothalamus/CNS): Activates hypothalamic circuits governing sexual arousal and motivation — the mechanism that led University of Arizona researchers to observe and document sexual arousal as an unexpected finding in early human volunteer studies, ultimately resulting in PT-141 development
- MC3R (hypothalamus/peripheral): Involved in energy homeostasis, feeding behavior, and inflammatory signaling. MC3R-mediated effects contribute to appetite suppression observed in MT-2 research models
- MC5R (exocrine glands): Regulates sebaceous gland secretion and other exocrine functions; relevant in skin biology research contexts
Melanotan 2 Research Data
- Photoprotection research (University of Arizona): Original preclinical studies confirmed MT-2 produced robust melanogenesis in animal models, with skin darkening measured by colorimetry. The hypothesis that pharmacological tanning could serve as a photoprotective strategy drove initial human volunteer trials in the 1990s
- Sexual function discovery: During University of Arizona human volunteer studies examining melanogenic effects, significant penile erection responses were documented as an unanticipated finding — leading directly to the research program that produced PT-141 (Bremelanotide, FDA-approved 2019 as Vyleesi)
- Appetite suppression: Rodent studies consistently demonstrate MT-2 reduces food intake and body weight in diet-induced obesity models through MC3R/MC4R-mediated hypothalamic signaling, independent of its melanogenic effects
- Anti-inflammatory: Cell culture and animal studies document MC1R-mediated anti-inflammatory effects in macrophage and neutrophil models, with reductions in TNF-α, IL-6, and reactive oxygen species production
Melanotan 2 Dosage Reference
| Research Context | Dose from Published Data | Route |
|---|---|---|
| Melanogenesis studies (human, early trials) | 0.01–0.1 mg/kg | IV or subcutaneous |
| Appetite suppression (rodent) | 0.1–1 mg/kg | IP or subcutaneous |
| Anti-inflammatory (in vitro) | Nanomolar–micromolar range | Cell culture |
| Melanocortin receptor binding (in vitro) | Ki ~0.2 nM (MC1R) | Radioligand competition assay |
Published research data provided for reference only. Not dosing guidance for human use.
Side Effects from Research Data
- Nausea — most consistently reported adverse event in human volunteer studies
- Facial flushing (melanocortin-mediated vasodilation)
- Spontaneous erections in male subjects (MC4R-mediated) — the finding that redirected research toward PT-141
- Increased melanocytic nevi (moles) reported with extended use in observational data
- Fatigue and yawning in some subjects
- Blood pressure changes at higher doses
Melanotan 2 vs. PT-141 — Melanocortin Research Comparison
| Parameter | Melanotan 2 | PT-141 (Bremelanotide) |
|---|---|---|
| Regulatory status | Research compound only | FDA-approved (Vyleesi) |
| Tanning potency (MC1R) | High | Lower (optimized away from MC1R) |
| Sexual function (MC4R) | Present — was the discovery compound | Primary approved indication |
| Appetite suppression | Yes (MC3R/MC4R) | Less studied |
| Clinical data depth | Early phase only | Phase 3 + FDA-approved |
Where to Buy Melanotan 2 for Research
MT-2’s cyclic peptide structure requires MS/MS verification to confirm correct cyclization and sequence integrity. Key supplier criteria:
- HPLC purity ≥99% with batch-specific documentation
- MS/MS identity verification confirming cyclic structure
- Third-party independent COA
- Lyophilized acetate salt format for stability
Core Power Peptides supplies Melanotan 2 Acetate (MT-2) 10mg at ≥99% purity, HPLC and MS/MS verified per batch, with third-party COA on request.
Research Disclaimer: All information on this page is for educational and scientific reference purposes only. Melanotan 2 is not approved for any therapeutic use. This product is sold strictly for in vitro research and laboratory use only. Not for human consumption. Not medical advice.