Melanotan II
A cyclic α-MSH analog activating MC1R, MC3R, MC4R. Key research tool in melanocortin pharmacology.
Mechanism of Action
Bioregulator compound with targeted biochemical activity.
Evidence Chain
Melanotan II
COMPOUND
1 Research Goal
• Skin & Cosmetic
Evidence Strength
2 articles sourced
Knowledge Graph
(3 connections)Research Evidence
(2)Melanotan II: α-MSH Analog Pharmacology, Clinical History, and Safety Profile
Melanotan II is a synthetic analog of α-melanocyte-stimulating hormone investigated in early-phase clinical trials for tanning and sexual dysfunction. This review summarizes its clinical evidence and notable safety concerns.
PT-141 / Bremelanotide: Melanocortin Agonist for Hypoactive Sexual Desire Disorder — Regulatory and Clinical Evidence
PT-141, developed as bremelanotide, is a melanocortin receptor agonist FDA-approved (Vyleesi) for premenopausal women with hypoactive sexual desire disorder. This review summarizes the registrational clinical evidence.
Overview
Melanotan II (MT2) is a synthetic cyclic peptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that was developed at the University of Arizona as part of research into skin cancer prevention through melanogenesis stimulation. MT2 activates multiple melanocortin receptors (MC1R, MC3R, MC4R, MC5R), producing effects on skin pigmentation, sexual function, appetite, and lipid metabolism. It has become a significant research tool in melanocortin pharmacology.
Mechanism of Action
MT2 acts as a non-selective agonist at melanocortin receptors. MC1R activation in melanocytes stimulates melanin production (melanogenesis), producing skin darkening without sun exposure. MC4R activation in the central nervous system influences sexual arousal and appetite regulation. MC3R activation affects energy homeostasis and sexual behavior. The broad receptor activity of MT2 produces multiple physiological effects simultaneously, making it a valuable research tool for studying melanocortin system function.
Research Highlights
Research demonstrated MT2's efficacy in stimulating melanogenesis, producing skin darkening in animal and human studies. Studies explored its potential in skin cancer prevention through increased melanin protection. Research showed significant effects on sexual function, with MT2 inducing erections in animal models and human subjects — leading to the development of bremelanotide (PT-141) as a targeted MC4R agonist. Studies also demonstrated appetite suppression and effects on lipid metabolism. The development of MT2 derivatives for specific clinical applications illustrates the pharmacological importance of the melanocortin system.
Dosage & Administration
In research, MT2 has been administered via subcutaneous injection at doses ranging from 0.25-1 mg per administration, typically in cycles with gradual dose escalation. For research use only (RUO).
Safety Profile
Reported side effects include nausea, flushing, spontaneous erections (priapism risk), darkening of existing moles and freckles, and transient blood pressure changes. The risk of priapism is a significant safety concern. MT2 has not been approved by the FDA for any indication. The compound has been associated with adverse events when used outside of clinical research settings.
References
Dorr RT, et al. Melanotan II pilot study. Life Sci. 1996. Hadley ME, et al. Melanocortin peptides and pigmentation. Pigment Cell Res. 2002. Wessells H, et al. Melanotan II and sexual function. J Urol. 2000. All content is for educational and research purposes only.
FDA 2026 Regulatory Update
As of April–June 2026, this compound was among the 14 peptides formally removed from the FDA's Category 2 restricted compounding list following review by the Pharmacy Compounding Advisory Committee (PCAC). This regulatory shift permits licensed compounding pharmacies to produce and dispense this compound under appropriate oversight, subject to final 503A Bulks List adjudication expected following the July 23–24, 2026 PCAC meeting. This does not constitute FDA approval for therapeutic use. All information on this page is for research purposes only.
Related Compounds
Synergy & Compatibility
(5)Computational assessment of bio-regulatory compatibility with compounds sharing research goals. Scores reflect half-life alignment, receptor target overlap, and bioavailability data.
Shared targets: mc3r, mc4r
Computational assessment based on available pharmacology data. Does not account for individual variability, dose-dependent effects, or unstudied interactions. For research use only.
Community Observations
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For research use only. Not medical advice.