Melanotan-2 (MT-2) — Compound Overview
A researcher-focused overview of Melanotan-2: its chemistry as a cyclic α-MSH analogue, its place in melanocortin research, and how each batch is documented.
Last updated: 2026-08-21 · By: Index Peptides technical team
Key facts about Melanotan-2
| Compound | Melanotan-2 |
|---|---|
| CAS number | 121062-08-6 |
| Molecular formula | C50H69N15O9 |
| Molecular weight | 1024.2 g/mol |
| Sequence | cyclo Ac-Nle-[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂ |
| Listed formats | 10mg per vial |
| Intended use | In-vitro laboratory research only |
What is Melanotan-2?
Melanotan-2 (MT-2) is a cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH). Cyclisation through a lactam bridge between aspartate and lysine side chains constrains the peptide's conformation and increases its potency at melanocortin receptors relative to linear analogues. PT-141 (bremelanotide) is its free-acid derivative.
Chemistry and structure
Melanotan-2 carries CAS registry number 121062-08-6, molecular formula C50H69N15O9 and a molecular weight of approximately 1024.2 g/mol (cyclo Ac-Nle-[Asp-His-D-Phe-Arg-Trp-Lys]-NH₂).
Regulatory status — read carefully
Melanotan-2 is not an approved medicine in any jurisdiction. UK and EU regulators have issued public warnings about consumer 'tanning' products containing it. Index Peptides supplies Melanotan-2 strictly for in-vitro laboratory research — never for tanning or any human use — and support cannot discuss such uses.
Melanotan-2 in the research literature
Melanotan-2 is a long-standing tool compound in melanocortin-receptor pharmacology, used in receptor-binding, selectivity and signalling studies across the MC1–MC5 receptor subtypes. The literature is preclinical and pharmacological in nature.
Form, handling and storage
Supplied as a lyophilised powder (acetate salt) in a sealed vial. Store at -20°C, desiccated and protected from light, per the batch record.
Batch documentation at Index Peptides
Review the published certificate for the exact lot, including the laboratory, report date and analytical results actually reported. HPLC purity alone does not confirm LC-MS identity. Contact us before ordering if a required result is not published.
Frequently asked questions
Is Melanotan-2 legal as a tanning product?
Melanotan-2 is not an approved medicine, and regulators including the MHRA have warned against consumer products containing it. Index Peptides supplies it strictly for in-vitro laboratory research, never for tanning or human use.
What is the difference between MT-2 and PT-141?
PT-141 (bremelanotide) is the free-acid derivative of Melanotan-2 — the C-terminal amide is replaced by a carboxylic acid, giving a different CAS number, mass and pharmacological profile.
How is each batch verified?
Reversed-phase HPLC for purity and LC-MS for identity, with the COA published on the product page and batch lookup by lot number.
How do I reconstitute Melanotan-2?
Reconstitution is a laboratory handling procedure, not a use instruction. Our documentation-led reconstitution guide covers the mechanics of dissolving lyophilised peptide powders: https://indexpeptides.uk/guides/peptide-reconstitution-guide. Handling is the responsibility of the qualified researcher.
What is the shelf life of Melanotan-2?
As supplied (lyophilised powder in a sealed vial), Melanotan-2 is stored at -20C, desiccated and protected from light. Long-term stability is documented per batch on the certificate of analysis; treat the batch record as the authoritative shelf-life reference for that lot.
What is the difference between the sizes?
The difference is the nominal peptide content per vial. Melanotan-2 is supplied as 10mg vials. Every format carries the same batch documentation and purity testing.
What does the certificate of analysis show?
Review the published certificate for the exact lot, including the laboratory, report date and analytical results actually reported. HPLC purity alone does not confirm LC-MS identity. Contact us before ordering if a required result is not published.
How does Melanotan-2 compare with Melanotan-1?
See our comparison of Melanotan-2 vs Melanotan-1: https://indexpeptides.uk/guides/melanotan-1-vs-melanotan-2
References
Research use only. Not for human or animal consumption.