Melanotan and melanocortin: research peptides

BritishPeps research team · Updated 18 July 2026 · ~6 min read

The melanocortin system is a receptor family studied in pigmentation research and related fields, and a small group of peptides serves as its reference compounds. This guide introduces Melanotan 1, Melanotan 2 and PT-141. It is informational only: all are supplied exclusively for in-vitro laboratory research and are not intended for human or veterinary use.

The melanocortin pathway

Melanocortin receptors respond to α-MSH (alpha-melanocyte-stimulating hormone) and related signals. Different receptor subtypes are associated with different themes in the literature, including pigmentation (melanogenesis) and other melanocortin-pathway questions. The compounds below are studied as analogues or agonists within this system.

Melanotan 1

Melanotan 1 (afamelanotide) is a linear α-MSH analogue studied in research on melanogenesis and UV photoprotection pathways. It is the more selective of the two Melanotan compounds.

Melanotan 2

Melanotan 2 is a cyclic melanocortin-receptor agonist studied in pigmentation research and in melanocortin signalling more broadly. Its cyclic structure makes it a distinct reference compound from Melanotan 1.

PT-141

PT-141 (bremelanotide) is a cyclic melanocortin-receptor agonist derived from α-MSH, studied specifically in melanocortin-pathway research away from pigmentation. It is included here because it shares the same receptor family.

Related compounds in cosmetic research

Researchers working on skin and cosmetic questions often study the melanocortin compounds alongside the copper peptide GHK-Cu and the expression-line peptide SNAP-8. Our GHK-Cu guide covers the copper-peptide side in more depth.

Frequently asked questions

Are these compounds for human use?

No. Melanotan 1, Melanotan 2 and PT-141 are supplied exclusively for in-vitro laboratory research and are not intended for human or veterinary use.

What is the difference between Melanotan 1 and Melanotan 2?

Melanotan 1 is a linear α-MSH analogue and is more selective; Melanotan 2 is a cyclic melanocortin-receptor agonist with broader receptor activity. They are distinct reference compounds.

How should they be stored?

Keep the lyophilised vials at −20 °C, protected from light. After reconstitution, keep them refrigerated at 2–8 °C.

For research use only. This content is informational. The products mentioned are supplied exclusively for scientific and in-vitro laboratory research, not for human, veterinary or cosmetic use. You must be 18 or over to place an order.