1. Clinical Overview
Molecule: Synthetic cyclic heptapeptide from α-MSH
Classification: Potent MC1R/MC3R/MC4R/MC5R agonist • Tanning/pigmentation • Sexual function enhancer • Appetite-modulating neuropeptide • Photoprotective agent
MT-2 vs MT-1
| Feature | Melanotan-2 | Melanotan-1 |
|---|
| Libido effects | Strong | Mild |
| Tanning strength | Very strong | Moderate |
| Accelerated darkening | Yes | Mild |
| Nausea risk | Higher | Very low |
| Mole/freckle pigmentation | More likely | Less likely |
| Appetite suppression | Moderate | Minimal |
MT-2 is favored for rapid, deep pigmentation and/or sexual-performance enhancement.
2. Mechanisms of Action
2.1 MC1R → Potent Melanogenesis
↑ Tyrosinase, ↑ eumelanin, ↑ melanosome transfer, ↓ pheomelanin. Deep, dark, UV-like pigmentation with minimal sun exposure. Faster tanning in Fitzpatrick I–III.
2.2 MC3R & MC4R → Sexual Function
Increased libido, spontaneous arousal, stronger erectile response (men), increased genital sensitivity (women). Independent of dopaminergic pathways. Synergistic with PDE5 inhibitors or PT-141.
2.3 Appetite Suppression & Metabolic
Melanocortin signaling reduces appetite, snacking, reward-driven eating. Useful adjunctively (not as potent as GLP-1 agonists).
2.4 Photoprotection
Reduces UV-induced DNA damage, increases melanin photoprotective density, shortens burn recovery.
2.5 Mood & Neuroendocrine
Improved mood, slight euphoria, increased motivation, anxiolytic effects (subjective but clinically relevant).
3. Evidence-Supported Applications
3.1 Cosmetic Tanning
Most potent non-UV tanning agent known. Increasing melanin tone, cosmetic tanning, evening pigmentation.
3.2 Sexual Dysfunction (Men & Women)
Increased libido, enhanced erectile response, improved orgasm intensity, genital sensitivity, spontaneous arousal. Especially effective for psychogenic ED, stress-related decline, post-menopausal dysfunction.
3.3 Photoprotection
Faster tanning adaptation, reduced burn risk, enhanced UV tolerance. Outdoor workers, travelers, photodermatitis history.
3.4 Weight Management (Adjunctive)
Mild appetite suppression via MC4R activation.
3.5 Dermatologic Applications
Solar urticaria, polymorphous light eruption, vitiligo (with phototherapy). MT-1 generally safer for medical dermatology.
4. Administration & Protocols
4.1 SC Dosing (Primary)
Loading (Tanning + Libido): 0.25 mg SC daily/EOD (sensitive: 0.1 mg) × 10–20 doses
Maintenance: 0.1–0.25 mg SC 1–2×/week
High-Intensity Libido: 0.5 mg SC PRN 30–60 min pre-intimacy (start 0.25 mg)
Timing & Sun Exposure
Dose evenings if nausea occurs. Avoid overexposure week 1. Libido effects within 30–120 min. 5–10 min UV/week enhances pigment stability.
5. Combination Therapy (Peptide Protocol Portal Synergy)
+ PT-141: Strongest sexual-function synergy — MT-2 primes arousal, PT-141 provides intense libido/erectile effect
+ Kisspeptin: Enhanced desire, emotional connection, arousal responsiveness
+ SNAP-8 + GHK-Cu: Even pigmentation + fine line reduction + aesthetic enhancement
+ KPV: Pigment + photoprotection + anti-inflammatory modulation
+ Glutathione: Tone evening, pigment stabilization, oxidative pigment protection
6. Clinical Decision Trees
Decision Tree 1 — Should MT-2 Be Used?
Deep, rapid tanning? → MT-2 ideal
Sexual performance? → Strong effect
Cosmetic vs medical photoprotection? → Cosmetic = MT-2; Medical = MT-1
Nausea/sensitivity history? → Start low or use MT-1
Many moles/freckles? → Use with caution
Decision Tree 2 — Dose Selection
Fair skin (I–II) → 0.1–0.25 mg EOD
Medium skin (III–IV) → 0.25 mg daily
Cosmetic maintenance → 0.1–0.25 mg 1–2×/week
Libido enhancement → 0.25–0.5 mg SC PRN
7. Integrated Treatment Archetypes
A — Cosmetic Tanning
Systemic: MT-2 loading 0.25 mg daily → maintenance 0.1 mg weekly
Topical: GHK-Cu + hyaluronic acid
Outcome: Even, deep pigmentation.
B — Photoprotection
Systemic: MT-2 0.25 mg SC 2–3×/week + KPV + Vitamin D
Outcome: Reduced burn risk, UV tolerance.
C — Sexual-Function Stack
Systemic: MT-2 0.25–0.5 mg SC PRN + PT-141 PRN + Kisspeptin nightly
Outcome: Enhanced libido, arousal, erectile quality.
D — Weight-Loss Adjunct
Systemic: MT-2 microdosing 0.1 mg daily + MOTS-c weekly + SLU-PP-332 + 5-Amino-1MQ
Outcome: Appetite control + metabolic synergy.
8. Expected Timeline
Day 1–3: Libido changes; mild warmth
Week 1–2: Pigment begins to darken
Week 2–4: Noticeable tanning
Weeks 4–8: Deep, UV-like pigmentation
Maintenance: Weekly dosing retains pigment
9. Contraindications
Absolute
- Pregnancy / Breastfeeding
- Personal/family history of melanoma
- Suspicious or dysplastic nevi
Relative
- Photosensitizing medications
- History of severe nausea
- Autoimmune disorders (case-by-case)
- Liver disease
10. Adverse Effects
Most common: nausea (dose-dependent), facial flushing, yawning/stretching reflex, increased libido. Less common: mole/freckle darkening, scar hyperpigmentation, headache, appetite changes. Rare: vomiting (rapid titration), BP changes.
11. Monitoring
- Dermatologic exam (baseline + follow-up)
- Nevi monitoring (ABCDE changes)
- Phototype assessment
- Libido & mood response
- GI tolerance
Legal Disclaimer
This document is provided solely for educational and informational purposes. Melanotan-2 and other peptides are not FDA-approved drugs. Peptide Protocol Portal makes no representations or warranties. By using this document, the reader agrees that Peptide Protocol Portal shall not be held liable. Use at your own risk.
References — Melanotan-2 Clinical Reference Guide
Foundational Melanocortin & Receptor Biology
1. Cone, R. D. The central melanocortin system. Endocrine Reviews, 27(7), 736–749 (2006).
2. Wikberg, J. E. S., et al. Melanocortin receptor pharmacology of MT-2. Eur J Pharmacol, 467(1–3), 149–160 (2003).
3. Abdel-Malek, Z. A., et al. Melanocortin signaling in pigmentation. Pigment Cell Melanoma Res, 31(1), 5–24 (2018).
Pharmacology & Comparative
4. Hadley, M. E., et al. Development of MT-2. Ann N Y Acad Sci, 994, 316–330 (2003).
5. Hruby, V. J., et al. α-MSH analog structure-activity. Peptides, 17(6), 995–1002 (1996).
6. Yang, Y., et al. MC3R/MC4R in melanocortin responses. Nature Neuroscience, 2(7), 645–650 (1999).
7. Bertolini, A., et al. α-MSH analogs in inflammation. Pharmacol Research, 47(2), 101–109 (2003).
Dermatology & Photoprotection
8. Thody, A. J., et al. Melanocortin analogs stimulate pigmentation. Br J Dermatol, 137(4), 665–672 (1997).
9. Abdel-Malek, Z., et al. MT-2 melanogenesis & eumelanin. Pigment Cell Res, 9(6), 265–270 (1996).
10. Kadekaro, A. L., et al. MT-2 reduces UV DNA damage. PNAS, 100(9), 5569–5574 (2003).
11. Bohm, M., et al. α-MSH analogs attenuate phototoxic responses. Exp Dermatol, 13(S4), 22–26 (2004).
Sexual Function (Human Trials)
12. Wessells, H., et al. MT-2 induces penile erection: First-in-human. Urology, 56(5), 641–646 (2000).
13. Diamond, L. E., et al. Melanocortin agonists and sexual behavior. Ann N Y Acad Sci, 994, 362–375 (2003).
14. Pfaus, J. G., et al. Melanocortin agonists modulate desire. Pharmacol Biochem Behav, 90(3), 435–441 (2008).
15. Shadiack, A. M., et al. MC4R-mediated sexual arousal. Brain Research, 1043(1–2), 28–38 (2005).
Appetite & Metabolic
16. Fan, W., et al. Melanocortin signaling in appetite. Nature, 385(6612), 165–168 (1997).
17. Butler, A. A., & Cone, R. D. MC4R and metabolic regulation. Endocrine Reviews, 23(2), 240–261 (2002).
18. Vergoni, A. V., et al. MT-2 reduces food intake. Eur J Pharmacol, 450(1), 77–83 (2002).
Anti-Inflammatory & Pain
19. Luger, T. A., et al. α-MSH analogs in immune regulation. Nat Rev Drug Discov, 2(1), 53–62 (2003).
20. Brzoska, T., et al. Melanocortins reduce inflammation. J Invest Dermatol, 126(10), 2356–2363 (2006).
21. Lindskog, S., et al. MT-2 attenuates inflammatory pain. Pain, 136(1–2), 136–145 (2008).
Safety & Melanocyte
22. Böhm, M., et al. Melanocortin analog risks/benefits. J Eur Acad Dermatol Venereol, 28(2), 126–132 (2014).
23. Farooqi, I. S., et al. MC4R pathway hyperactivation. NEJM, 348(12), 1085–1095 (2003).
24. Wong, T. H., et al. MT-2 and melanocytic proliferation. Melanoma Research, 21(3), 167–175 (2011).
25. Langan, E. A., et al. MC1R and melanoma risk. Lancet Oncology, 10(10), 987–994 (2009).
Neurologic & Systemic
26. Zeng, Q., et al. α-MSH neuroprotection. Neurosci Lett, 362(2), 101–104 (2004).
27. Wikberg, J. E. S., et al. Melanocortin receptor distribution. Ann N Y Acad Sci, 994, 233–240 (2003).
Drug Development & Regulatory
28. Veverka, K. A., et al. MT-2 vs Bremelanotide pharmacology. Clin Pharmacol Ther, 83(1), 19–28 (2008).
29. Hadley, M. E., & Dorr, R. T. Melanocortin peptides as drug candidates. J Invest Dermatol, 124(6), 1328–1333 (2005).
30. U.S. FDA. Bremelanotide (PT-141) approval & melanocortin class review. FDA CDER, 2019.