MECHANISM OF ACTION
Melanotan II (MT-II) is a cyclic lactam analogue of α-MSH, non-selectively agonising MC1R (melanogenesis), MC3R (energy homeostasis), MC4R (sexual function, satiety), and MC5R (exocrine). MC1R constitutive activation increases melanin production without UV exposure. The related compound PT-141 (Bremelanotide) received FDA approval for HSDD via its MC4R activity - validating the receptor mechanism that MT-II first demonstrated.
RESEARCH APPLICATIONS
- Melanogenesis and photoprotection (Melano Glow)
- MC4R sexual dysfunction models
- Energy homeostasis and lipolysis (MC3R/MC4R)
- Melanoma and UV-damage protection
- Appetite suppression via central MC4R
RESEARCH HIGHLIGHTS
Tanning Without UV - Phase II
1991RCT (n=30, phototypes I–II): significant Fitzpatrick skin type shift after 2-week MT-II vs. placebo without UV exposure, confirming MC1R-mediated melanogenesis.
Ref: Dorr et al., JAMA
MC4R Erectile Function
1998Crossover RCT: MT-II SC produced erection (rigidity >80%) in 17/20 psychogenic ED subjects vs. 5/20 placebo.
Ref: Wessells et al., J Urology
RESEARCH PROTOCOL NOTES
Chemical Identity
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Storage & Stability
Lyophilised: -20°C or 2–8°C. Reconstituted: 2–8°C, 21 days. Light sensitive.
Regulatory Status
No regulatory approval. Related analogue Bremelanotide (PT-141) = FDA approved for HSDD. MT-II = research only. Not explicitly WADA prohibited.