Skip to content

Melanotan-1 (Afamelanotide)

Melanotan-1 (afamelanotide, CAS 75921-69-6) is a synthetic 13-amino acid cyclic peptide analog of α-melanocyte-stimulating hormone (α-MSH) with a molecular weight of approximately 1,646.8 Da. As the first synthetic melanocortin peptide developed for human research, Melanotan-1 is a selective MC1R (melanocortin-1 receptor) agonist that potently stimulates eumelanin synthesis in melanocytes. It is a primary research tool in melanocortin receptor pharmacology, melanogenesis, and photoprotection biology.

Technical Specifications

Property Value
CAS Number 75921-69-6
Molecular Formula C₇₈H₁₁₁N₂₁O₁₉
Molecular Weight ~1,646.8 Da
Purity ≥98% (HPLC-verified)
Appearance Lyophilized white powder
Solubility Soluble in sterile water and aqueous buffers
Storage -20°C (lyophilized), 2–8°C (reconstituted)

Mechanism of Action

Melanotan-1 binds with high affinity and selectivity to the melanocortin-1 receptor (MC1R), a Gαs-coupled GPCR expressed primarily on epidermal melanocytes. MC1R activation stimulates adenylyl cyclase, increasing intracellular cAMP and activating PKA, which phosphorylates the cAMP response element-binding protein (CREB). CREB then drives transcription of the microphthalmia-associated transcription factor (MITF), the master regulator of melanocyte differentiation and function. MITF upregulates the expression of key melanogenic enzymes — tyrosinase (TYR), tyrosinase-related protein 1 (TYRP1), and dopachrome tautomerase (DCT) — leading to increased synthesis of eumelanin (brown/black photoprotective pigment) over pheomelanin (red/yellow pigment). The resulting eumelanin deposition in keratinocytes provides enhanced photoprotection through UV absorption and free radical scavenging. Unlike Melanotan-2, Melanotan-1 exhibits high MC1R selectivity with minimal MC3R/MC4R engagement, producing melanogenesis without significant central nervous system or appetite effects.

Research Applications

  • Primary: Melanocortin-1 receptor pharmacology — eumelanin synthesis, MITF signaling, melanocyte biology
  • Secondary: UV photoprotection and DNA damage research, erythropoietic protoporphyria (EPP) models, skin pigmentation genetics
  • Model Systems: In vitro (primary human melanocytes, B16-F10 melanoma cells, MC1R-transfected HEK293), in vivo (skin pigmentation and UV challenge models in rodents)

Quality Control & Analytical Methods

  • HPLC: ≥98% purity verification at 214/220 nm (C18 reversed-phase column)
  • Mass Spectrometry: ESI-MS for molecular weight confirmation (~1,646.8 Da)
  • Peptide Content: Amino acid analysis (AAA) for net peptide content determination
  • Endotoxin: <1 EU/mg (LAL assay)
  • TFA Content: <1% (ion chromatography)

Stability & Storage

Condition Stability
-20°C (lyophilized) 24 months
4°C (lyophilized) 6 months
25°C (lyophilized) 1 month
Reconstituted (4°C) 7 days
Reconstituted (-20°C) 30 days

Key Research References

  • Hadley & Dorr (2006) — Melanocortin peptides: from the bench to the bedside. Peptides. PMID: 16558908
  • Minder et al. (2009) — Afamelanotide for erythropoietic protoporphyria. N Engl J Med. PMID: 19164166
  • Abdel-Malek et al. (2006) — The melanocortin-1 receptor and human pigmentation. Pigment Cell Res. PMID: 16979598

Source & Purchase

For researchers requiring research-grade MELANOTAN 1 with full analytical documentation including HPLC, LC-MS, and Certificate of Analysis, visit the HK Peptides product page for specifications, bulk pricing, and ordering.

View MELANOTAN 1 Product →

FAQ

Q: What purity level is standard for Melanotan-1? A: HK Peptides supplies Melanotan-1 at ≥98% purity by HPLC with full COA documentation.

Q: How should Melanotan-1 be stored for research use? A: Lyophilized Melanotan-1 should be stored at -20°C, protected from light. Reconstituted solutions at 4°C for short-term use (up to 7 days).