Melanotan I (Afamelanotide) Research Guide: MC1R Agonist Data & Mechanism
What Is Melanotan I?
Melanotan I (also known as Afamelanotide, MT-1, or NDP-α-MSH) is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH). It is a linear tridecapeptide designed for greater metabolic stability and higher binding affinity than native α-MSH. In research contexts, Melanotan I is studied primarily as a selective melanocortin-1 receptor (MC1R) agonist and as a tool for investigating melanogenesis pathways.
Unlike its more widely known counterpart Melanotan II (MT-2), which is a cyclic peptide with broad melanocortin activity, Melanotan I is more selective for MC1R, making it a valuable comparator in receptor-specificity studies.
Mechanism & Research Background
Melanotan I acts as an agonist at the MC1R, a G-protein-coupled receptor expressed on melanocytes. Receptor activation elevates intracellular cyclic AMP (cAMP), which upregulates microphthalmia-associated transcription factor (MITF) and downstream enzymes such as tyrosinase, driving eumelanin synthesis. Because MC1R signaling is central to the skin’s pigmentation and photoprotective response, Melanotan I has been used in laboratory models examining melanogenesis, oxidative stress in melanocytes, and melanocortin receptor pharmacology.
The [Nle4, D-Phe7] substitutions that define the NDP-α-MSH structure confer resistance to enzymatic degradation and substantially increase potency relative to endogenous α-MSH, which is why the molecule is a preferred reference agonist in in-vitro receptor assays.
Technical Data
| Compound | Melanotan I / Afamelanotide / NDP-α-MSH |
| CAS Number | 75921-69-6 |
| Molecular Formula | C₄₃H₁₁₁N₂₁O₁₉ |
| Molecular Weight | ~1646.9 g/mol |
| Sequence | Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH₂ |
| Form | Lyophilized powder |
| Target | Melanocortin-1 receptor (MC1R) agonist |
Handling & Storage
Store lyophilized Melanotan I at −20 °C, protected from light and moisture. Once reconstituted in sterile or bacteriostatic water, keep refrigerated at 2–8 °C and use within the working window typical for reconstituted peptides. Avoid repeated freeze-thaw cycles, which can degrade peptide integrity. For reconstitution, bacteriostatic water is commonly used in laboratory settings.
Frequently Asked Questions
How does Melanotan I differ from Melanotan II?
Melanotan I (NDP-α-MSH) is a linear peptide with greater MC1R selectivity, while Melanotan II is a cyclic peptide with broader melanocortin receptor activity, including MC3R and MC4R.
Is Melanotan I the same as Afamelanotide?
Yes — Afamelanotide is the international nonproprietary name for the same NDP-α-MSH molecule studied under the Melanotan I designation.
What receptor does it target?
Primarily the MC1R, where it acts as a potent agonist driving cAMP-mediated melanogenesis pathways in research models.
Buy Melanotan I for Research
Zama Biosciences offers Melanotan I (MT-1) 10mg for laboratory research. Related melanocortin research compounds include Melanotan II (MT-2) and PT-141 (Bremelanotide). Browse the full Peptide Research Library for related mechanism guides.
Research Use Only. All products sold by Zama Biosciences are intended strictly for in-vitro laboratory research and are not for human or veterinary use, consumption, or diagnostic purposes. The information on this page is provided for educational purposes and does not constitute medical advice.