MECHANISM OF ACTION
Melanotan II is a modified version of a natural hormone (alpha-MSH) that your skin normally uses to produce melanin (the pigment that makes skin darker). By directly activating the melanin-production switch, it triggers tanning without sunlight. But it doesn't stop there, it also activates other receptors (the same family of switches) that are found in the brain. One of these controls sexual arousal and appetite. This is the same receptor that the FDA-approved drug Bremelanotide (PT-141) acts on, and PT-141 was actually developed from Melanotan II research. Because it activates multiple receptor types non-selectively, it also comes with a stronger side effect profile (nausea, flushing, spontaneous erections) compared to more targeted compounds.
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.