Peptide Protocol

Melanotan II: broad-spectrum melanocortin — tan, libido, appetite.

Non-selective MC1–4R agonist. Potent tanning, sexual arousal (MC4R), and appetite suppression. Significant side effect profile.

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0.25–1 mg
Per Dose
2–4 weeks on / 4 off
Cycle
SubQ
Route
Daily or as needed
Frequency
Overview

What is Melanotan II?

Melanotan II was developed at the University of Arizona as a potent melanocortin agonist, initially with the goal of producing a 'sunless tan' for photoprotection. Its cyclic structure (cyclo[Nle4, Asp5, D-Phe7, Lys10]-α-MSH(4-10)) confers exceptional potency and receptor breadth — activating all four melanocortin receptors (MC1–4R) with high affinity.

MC4R activation produces its well-known sexual arousal effects (spontaneous erections in males, increased sexual desire), while MC3R activation is associated with appetite suppression and MC1R drives melanogenesis. These combined effects have generated significant research interest for erectile dysfunction, female sexual arousal disorder, and melanogenesis — but also account for its significant side effect profile.

🎨
MC1R Melanogenesis
Activates MC1R on melanocytes to drive eumelanin synthesis and rapid skin darkening — produces tan within days of starting research protocols.
❤️
MC4R Sexual Arousal
MC4R activation in the hypothalamus and spinal cord produces sexual arousal, spontaneous erections in males, and increased libido in females.
🍽️
MC3R Appetite Suppression
MC3R/4R activation reduces appetite and food intake through hypothalamic mechanisms — studied for obesity but complicated by other receptor effects.
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Non-Selective Profile
Broad receptor activation produces predictable side effects: nausea (nausea center MC1R/4R), facial flushing, and spontaneous erections.
Dosing Protocol

Dosing Schedule

Parameters documented in published preclinical and clinical research.

⚠️ Research use only. The following documents parameters from published preclinical and clinical research. Not medical advice. Not for human consumption. Consult a licensed healthcare professional before any use.
PhaseDoseFrequencyDurationNotes
Start0.25 mgDaily SubQ (evening)Days 1–5Very low starting dose to assess nausea and flushing tolerance.
Loading0.5–1 mgDaily SubQWeeks 1–4Increase gradually per tolerance. Take before sleep to sleep through nausea.
Maintenance0.5 mgEvery 2–3 daysPer protocolLower-frequency maintenance once target pigmentation achieved.
Acute use0.5–1 mg1–2h before activityAs neededPre-activity dosing for sexual arousal effect research.
Safety Profile

Safety & Side Effects

✓ Generally Well Tolerated
Rapid tanning effect — photoprotective melanogenesis within days
Potent erectogenic effects studied for ED research (led to PT-141 development)
Short half-life — effects resolve quickly if dose is reduced
Appetite-suppressing effects of interest for metabolic research
⚠ Potential Concerns
Nausea common — especially at higher doses
Spontaneous, unwanted erections at working doses in males
Facial flushing and yawning common
Not FDA-approved — no quality-controlled pharmaceutical supply
⚠️
Research use onlyThis page is an educational reference. None of this constitutes medical advice. Consult a qualified professional before any use. All compounds are for research purposes only.
Evidence Base

Academic References

  1. [1]
    Dorr RT, et al. (1996). Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 58(20):1777–84. PubMed ↗
  2. [2]
    Wessells H, et al. (1998). Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction. Urology. 51(6):1024–7. PubMed ↗
  3. [3]
    Hadley ME, Dorr RT. (2006). Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization. Peptides. 27(4):921–30. PubMed ↗
  4. [4]
    King SH, et al. (2007). Melanotan II treatment and penile erection in rats with a cavernous nerve crush injury. J Urol. 177(1):362–6. PubMed ↗
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