Melanotan II: MC Receptor Agonism in Preclinical Research

What is Melanotan II?

Melanotan II (MT-2 for short) is a lab-made peptide (a short chain of amino acids, the building blocks of proteins). It is a copy of a natural hormone called alpha-melanocyte-stimulating hormone (α-MSH). In lab tests it flips a set of cell switches called melanocortin receptors. Scientists use it as a reference tool to study how those switches work. It is sold strictly as a research chemical for in vitro use (test-tube and lab work only). It is not a medicine, and it is not for use by people or animals, and not for tanning or cosmetic use of any kind.

MT-2 was first made at the University of Arizona in the 1980s and 1990s. Its chemical chain is joined into a ring shape, which makes it tougher and longer-lasting than the natural α-MSH hormone. There are five of these melanocortin switches, named MC1R through MC5R. In the lab MT-2 turns on four of them — MC1R, MC3R, MC4R and MC5R — but mostly leaves the fifth one (MC2R) alone. Because it activates so many at once, it is one of the broadest "switch-flippers" used in research.

That broad reach is exactly what makes it handy in the lab. The melanocortin system is involved in many things in the body, so a stable peptide that switches on several receptors gives researchers one steady reference chemical. They can line up other, more targeted chemicals against it to compare how each one behaves. These are research observations only, not effects in people.

Melanocortin receptor agonism

Melanotan II research is grouped around the cell switches it turns on: the pigment switch MC1R, the brain switches MC3R and MC4R, and its overall value as a broad reference tool.

Non-selective melanocortin agonism

An agonist is something that turns a receptor "on". MT-2 turns on four melanocortin switches — MC1R, MC3R, MC4R and MC5R — and mostly skips the fifth (MC2R). This is the main feature researchers study, because each switch controls a different job in the body and MT-2 hits several of them at the same time.

MC1R and the pigmentation pathway

MC1R is a switch found on melanocytes — the cells that make melanin, the pigment that gives skin and hair its colour. In cell and animal studies, scientists use MT-2 to turn on MC1R so they can watch how this switch controls pigment production. These are research observations only, not therapeutic or cosmetic effects in people.

MC3R / MC4R and central pathways

MC3R and MC4R are switches found in the brain and nerves. Researchers study them for their part in energy use and feeding (how and when animals eat). In rodent studies, MT-2 has been used to test what these switches do for appetite, which makes it a tool for taking apart how the brain’s melanocortin signals work. Again, these are research observations only, not effects in humans.

A reference agonist for receptor-selectivity research

Because MT-2 turns on several switches at once, scientists often use it as a "yardstick" chemical. They compare newer chemicals that target just MC3R or just MC4R against MT-2 to see how those narrower ones behave. This makes it an important lab reference in melanocortin research.

Key research findings

The studies below (done in cells and animals, not people) show how MT-2 is used as a melanocortin research tool. They are summarised here for science reference only.

Velox Peptides supply information

Velox Peptides supplies Melanotan II as a lyophilised (freeze-dried) powder at ≥99.3% purity, checked by HPLC (a lab method that measures how pure a sample is). A batch certificate of analysis is available on request. To work out how to mix the powder back into a liquid (reconstitute it), see the reconstitution calculator. Supplied strictly as a research chemical for in vitro (lab-only) use — not for human, cosmetic, tanning or veterinary use.

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