PeptiDex
Peptide Research Index
Research-backed
Peptide Research Index
⚠️ Educational only · Not medical advice · Consult a doctor · Most peptides are research-only / not FDA-approved for human use
⚠️ Educational only · Not medical advice · Consult a doctor · Most peptides are research-only / not FDA-approved for human use
Also: MT-II, MT-2
🎨Melanocortin AgonistMC4R activation. Non-selectively activates melanocortin receptors to stimulate melanin production, suppress appetite, and increase sexual arousal.
Dorr et al. (J. Investigative Dermatol.): Phase I trial in normal male volunteers confirming tanning activity and spontaneous penile erections. Side effects: nausea, somnolence.
moderateWessells et al. (J. Urology): Double-blind study showing MT-II initiates erection in men with erectile dysfunction even without sexual stimulation.
moderateHadley & Dorr (Peptides): Review of MT-II as potential chemopreventive agent for UV-induced skin cancer through enhanced eumelanin synthesis.
preclinicalHruby et al. describe development of functionally selective melanocortin receptor agonists derived from MT-II to separate desired from unwanted pharmacological effects.
preclinicalNausea common; research-only. SIGNIFICANT SAFETY CONCERNS: changes to moles, elevated BP. Actively warned against by FDA/TGA.
⚠️ For educational purposes only. Not medical advice. Consult a healthcare professional before using any peptide.
Loading: 250mcg/day for 7-10 days. Maintenance: as needed for UV exposure. START LOW.
Last updated: 2026-01 · Laws change frequently. Verify current status in your jurisdiction.
Week 1
Nausea common during initial dose; spontaneous erections in men; early tanning begins
Weeks 2-4
Significant skin pigmentation; libido effects
Long-term
Persistent tan maintained with UV exposure; long-term safety concerns with mole changes
| Side Effect | Incidence | Severity |
|---|---|---|
Nausea Most common side effect; dose-dependent | ~45% of users | moderate |
Facial flushing | ~30% of users | mild |
Fatigue | ~15% of users | mild |
Spontaneous erections (men) | ~20% of men | mild |
Mole changes (darkening) Monitor moles carefully; can mask melanoma | Variable | uncommon |
Incidence rates sourced from published clinical trial data where available; otherwise based on community research observations.
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