Melanotan 1 Research: What the Studies Show
Melanotan 1 — scientifically afamelanotide, or [Nle4, D-Phe7]-α-MSH — is the one melanocortin analogue whose research programme carried it from a synthetic tanning peptide through to an approved photoprotective medicine. Unlike Melanotan 2, it is highly selective for the melanocortin-1 receptor.
Mechanism of action
Melanotan 1 is a linear analogue of α-melanocyte-stimulating hormone with two substitutions (Nle at position 4, D-Phe at position 7) that make it far more stable and potent than the natural hormone.
It is selective for the melanocortin-1 receptor (MC1R) on melanocytes, which is what separates it from the broader, less selective Melanotan 2.
MC1R activation drives eumelanin synthesis independent of sunlight, so pigmentation develops without the DNA damage signal that normally initiates tanning.
Because eumelanin absorbs and scatters ultraviolet and visible light, the resulting pigment acts as physical photoprotection — the basis of its approved clinical indication.
The studies
The first two entries are early human pharmacology; the CUV029/CUV039 programme is the pivotal Phase 3 evidence that led to regulatory approval; the vitiligo work is Phase 2. Regulatory status is summarised at the end.
Early human pharmacology
Dose-finding trials — establishing 0.16 mg/kg
Finding the optimal subcutaneous human dose for sunless skin darkening.
Open-label dose-finding study (Dorr et al.) · escalating subcutaneous daily doses
- 0.16 mg/kg/day
- Optimal dose
- 10 days
- Duration
- Face & neck
- Most responsive sites
Forehead, cheeks, neck
- 0.16 mg/kg per day for 10 days was identified as the optimal regimen for sunless darkening.
- Lower doses produced less pigment; higher doses caused pronounced gastrointestinal distress and fatigue without increasing pigment yield.
- Response was regional — forehead, cheeks and neck darkened most readily.
Synergistic UV-B radiation trials
Safety and effect of combining Melanotan 1 with standard UV-B radiation or natural sunlight.
Three Phase 1 randomised controlled trials · peptide plus UV-B/sunlight versus light alone
- 50% less
- Sun exposure needed
- 47% fewer
- Sunburn cells
- +3 weeks
- Tan persistence
for identical pigment depth
versus controls
- The peptide acted synergistically with light rather than replacing it — tans were deeper and lasted at least three weeks longer than in controls.
- Participants needed 50% less sun exposure time to reach the same pigment depth.
- Histology showed 47% fewer sunburn cells, the marker of UV-induced keratinocyte damage.
- Reported side effects were limited to transient facial flushing and mild nausea.
Pivotal Phase 3 programme
CUV039 & CUV029 — erythropoietic protoporphyria
Whether a slow-release afamelanotide implant increases pain-free light exposure in erythropoietic protoporphyria (EPP), a genetic condition in which visible light causes severe burning pain.
Multi-centre, double-blind, placebo-controlled · 16 mg slow-release subcutaneous implant (Scenesse) · 6-month observation
- 69.4 h
- Pain-free light exposure
- 40.8 h
- Placebo comparison
- ~50% fewer
- Severe phototoxic reactions
median over 6 months
- Treated patients recorded a median 69.4 hours of pain-free sun exposure over six months versus 40.8 hours on placebo.
- The total count of severe phototoxic skin reactions fell by roughly half.
- These results are the evidence base on which the implant was approved for adult EPP patients.
Dermatology beyond EPP
Vitiligo combination therapy with narrowband UV-B
Whether monthly afamelanotide implants improve repigmentation over narrowband UV-B phototherapy alone.
Open-label Phase 2 · monthly implants plus NB-UVB versus NB-UVB alone · generalised vitiligo · 168 days
- 48.6%
- Combination therapy
- 33.2%
- NB-UVB alone
- Fitzpatrick IV–VI
- Best responders
repigmentation by day 168
- Combination therapy produced faster, deeper and more uniform repigmentation than phototherapy alone.
- The effect was strongest in darker skin types (Fitzpatrick IV–VI).
- In very fair skin the approach was less practical, because surrounding healthy skin tanned strongly and increased contrast.
Regulatory status
Approved status — FDA and EMA
How the Phase 3 outcomes translated into approved medicines, and what remains unapproved.
Marketing authorisations for Scenesse (afamelanotide) 16 mg controlled-release implant
- Approved
- U.S. FDA
- Approved
- EMA
- Every 60 days
- Dosing interval
Adult EPP
Year-round EPP protection
- Scenesse — a 16 mg controlled-release implant given once every 60 days — is approved exclusively for adult EPP patients.
- The European Medicines Agency authorised it for year-round photoprotection in EPP.
- Injectable liquid and nasal-spray products sold online as "Melanotan 1" are unregulated, unapproved research chemicals and are not the approved implant.
Storage & handling
Melanotan 1 is supplied as a lyophilised powder. Keep sealed vials refrigerated or frozen, protected from light and moisture.
Reconstitute with bacteriostatic water directed slowly down the inner wall of the vial and swirl gently until clear. Do not shake.
Store reconstituted solution at 2-8 °C, shielded from light, and use within the stability window set by your lab's standard operating procedures.
All information on this page is provided for laboratory and educational reference only. Peptides Lab SA (PTY) Ltd supplies compounds strictly for in-vitro research use. Nothing here is medical advice, a dosing recommendation, or a claim of human safety or efficacy.