What Is Melanotan 1 (MT-1)?
Melanotan 1, also known as afamelanotide, is a linear tridecapeptide analogue of alpha-melanocyte stimulating hormone (ฮฑ-MSH). It was developed at the University of Arizona in the 1980s as part of a research program to create photoprotective agents. Unlike the naturally occurring ฮฑ-MSH, MT-1 has a significantly longer half-life โ approximately 60 times longer โ due to amino acid substitutions that increase resistance to enzymatic degradation.
MT-1 has reached clinical drug status in some regions. The European Medicines Agency (EMA) approved afamelanotide (brand name Scenesse) in 2014 for the prevention of phototoxicity in adults with erythropoietic protoporphyria (EPP), making it the first approved melanocortin receptor agonist drug.
Mechanism of Action
MC1R Agonism
MT-1 acts primarily as an agonist at Melanocortin Receptor 1 (MC1R), which is highly expressed on melanocytes โ the cells responsible for melanin production. Upon MC1R activation, intracellular cAMP levels rise, triggering the tyrosinase enzyme cascade that converts tyrosine to melanin. The predominant melanin produced under MT-1 stimulation is eumelanin (dark pigment) rather than phaeomelanin (light/red pigment).
Photoprotection Research
The clinical approval of afamelanotide for EPP is directly predicated on its ability to increase skin eumelanin density before UV exposure, effectively increasing the skin's natural photoprotective capacity. Research suggests that eumelanin provides approximately 100x more UV protection per unit than phaeomelanin.
Research Summary
| Area | Model | Key Observation |
|---|---|---|
| Melanin Production | Human melanocytes, in vivo | Significant increase in eumelanin density |
| EPP Photoprotection | Human clinical (EMA-approved) | Reduced phototoxic reactions |
| UV Protection | Human skin biopsies | Elevated eumelanin-to-phaeomelanin ratio |
| Vitiligo Research | Clinical | Pigmentation stimulation in depigmented areas |
MT-1 vs MT-2: Key Differences
| Property | MT-1 (Afamelanotide) | MT-2 (Melanotan 2) |
|---|---|---|
| Structure | Linear peptide | Cyclic peptide |
| Primary receptor | MC1R | MC1R, MC3R, MC4R, MC5R |
| Melanin focus | Eumelanin dominant | Broader melanin stimulation |
| Clinical status | EMA-approved (EPP) | Research only |
| Selectivity | More selective | Broader multi-receptor activity |
Storage
Store lyophilized MT-1 at โ20ยฐC, protected from light. After reconstitution with bacteriostatic water, refrigerate at 2โ8ยฐC and use within 30 days.
For research use only. Not for human or animal use. Order MT-1 here.