What Is Melanotan II?

Melanotan II is a cyclic synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH), engineered in the early 1990s for potency and stability far beyond the linear native hormone. It went on to become the reference agonist of melanocortin-receptor research.

What is Melanotan II?

Native α-MSH degrades in minutes; Melanotan II's cyclic lactam bridge locks its active conformation into a shape enzymes struggle to attack. That single design change turned a fragile hormone into a durable laboratory tool with broad agonism across the melanocortin receptor family — and spawned derivatives, most notably PT-141.

What researchers study it for

MT-II's home turf is melanogenesis and pigmentation-signalling research, where it is the standard receptor agonist. Beyond that, it serves as the benchmark against which selective melanocortin ligands are compared — including the narrower probes at both ends of the family, from its own derivative PT-141 to the minimal α-MSH fragment KPV. If a protocol touches melanocortin receptors, MT-II is usually somewhere in the comparison table — see PT-141 vs Melanotan II and the melanocortin family guide.

Working with research-grade Melanotan II

REPRIME supplies Melanotan II as a lyophilized 10 mg vial, HPLC-verified per batch with a public COA and first-scan verification code. See the Melanotan II product page. Research use only.

Frequently asked questions

What is Melanotan II?

A cyclic synthetic analog of α-MSH with broad melanocortin-receptor agonism — the reference agonist in melanogenesis and receptor-pharmacology research.

Why is Melanotan II more stable than α-MSH?

Its cyclic lactam bridge locks the peptide's conformation, resisting the enzymatic degradation that clears the linear native hormone within minutes.

How is research-grade Melanotan II supplied?

As a lyophilized 10 mg vial with batch HPLC verification, a public COA, and a verification code — see the product page.