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.

Melanotan-2 (MT-2)