# Melanotan II

> Synthetic cyclic analog of α-MSH; non-selective melanocortin receptor agonist.

- Also known as: MT-2, MT-II
- Class: Cosmetic, Reproductive
- FDA approved: No
- Canonical page: https://www.americanpeptide.com/catalog/melanotan-2

## Overview

Melanotan II is a cyclic heptapeptide α-MSH analog developed at the University of Arizona. Acts as a non-selective agonist across MC1R, MC3R, MC4R, and MC5R — pigmentation and sexual-response effects have both been documented.

Melanotan II is a synthetic cyclic analog of α-melanocyte-stimulating hormone (α-MSH), developed at the University of Arizona. It is a non-selective agonist across the melanocortin receptors MC1R through MC5R.

Through MC1R it stimulates melanin production (pigmentation); through MC4R it influences central sexual-response pathways. Both effects are documented in research, but its non-selectivity also drives side effects, and it is not FDA-approved.

## Mechanism

Non-selective melanocortin receptor (MC1-5R) agonism.

## Chemistry

| Property | Value |
| --- | --- |
| Molecular formula | C50H69N15O9 |
| Molecular weight | 1024.2 Da |
| CAS number | 121062-08-6 |
| PubChem CID | [92432](https://pubchem.ncbi.nlm.nih.gov/compound/92432) |

## Research areas

Studied in: Pigmentation biology, Sexual dysfunction, Photoprotection.

Guides on this site:

- [Skin & Hair](https://www.americanpeptide.com/research-areas/skin-hair): Peptides studied for skin aging, pigmentation, and hair follicle biology.
- [Sexual & Reproductive Health](https://www.americanpeptide.com/research-areas/sexual-reproductive): Peptides studied across the HPG axis and CNS sexual-response pathways.

## Key research

- Pigmentation — MC1R agonism stimulates eumelanin production via Gs-coupled cAMP signaling.
- Central sexual response — MC4R activation drives arousal effects; the same MC4R activity also produces the nausea, flushing, and spontaneous erections documented in human studies.
- Compared to Melanotan I (afamelanotide) — MT-II is a truncated, non-selective MC1–5R agonist, whereas afamelanotide is highly MC1R-selective and FDA-approved (Scenesse) for photoprotection in erythropoietic protoporphyria.
- Relationship to PT-141 — PT-141 (bremelanotide) is a metabolite refined toward MC4R / sexual response and away from pigmentation.
- Not FDA-approved — its non-selectivity drives off-target effects; research compound.

## FAQs

### What is Melanotan II?

Melanotan II is a synthetic, non-selective melanocortin-receptor agonist (an α-MSH analog) studied for pigmentation and sexual-response effects.

### How is it related to PT-141?

PT-141 (bremelanotide) is a melanocortin agonist with preferential MC4R activity studied for sexual function; Melanotan II is non-selective and also drives pigmentation.

### Is it approved?

No — Melanotan II is not FDA-approved. This page is a research and educational reference, not a usage recommendation.

### What receptors does it act on?

It activates melanocortin receptors MC1R through MC5R without selectivity.

## Latest research

Recent trials and publications mentioning Melanotan II, pulled automatically from ClinicalTrials.gov and PubMed (unfiltered search results, refreshed daily).

### Recent trials

- [Melanotan II (MT-II) as an Adjunct to NB-UVB Phototherapy for Repigmentation in Stable Nonsegmental Vitiligo](https://clinicaltrials.gov/study/NCT07437560) — RECRUITING · PHASE2 · NCT07437560

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Source: AmericanPeptide.com — https://www.americanpeptide.com/catalog/melanotan-2
Data license: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Attribution: AmericanPeptide.com.
Research reference only — computational and educational content, not medical advice.