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Healing & Recovery
Phase 1

Melanotan II

Melanotan II

Also known as: MT-2, MT-II, Melanotan 2

Overview

Key Facts

Primary Goal: Research and therapeutic applications of Melanotan II

Non-selectively agonizes melanocortin receptors MC1R (skin pigmentation), MC3R and MC4R (sexual function and energy homeostasis), and MC5R. MC1R activation stimulates melanogenesis in melanocytes, increasing eumelanin production.

Dosing Information

Half-Life

~1 hour

Typical Dose

250–1000 mcg

Frequency

initially daily for loading, then 1-2 times weekly for maintenance

Cycle Length

Loading phase of 1-2 weeks, then ongoing maintenance as needed

Administration Routes:
subcutaneous

Benefits

  • Promotes significant skin tanning without UV exposure
  • Notable pro-sexual effects including enhanced libido and spontaneous erections
  • Moderate appetite suppression and potential fat loss
  • Cross-functional effects on both tanning and sexual function

Side Effects

Nausea, especially during initial dosesmild
Facial flushingmild
Fatigue and drowsinessmild
Darkening of existing moles (requires monitoring)mild
Spontaneous or prolonged erections in menmild
Potential new nevus (mole) formationmild

Mechanism of Action

1

Non-selectively agonizes melanocortin receptors MC1R (skin pigmentation), MC3R and MC4R (sexual function and energy homeostasis), and MC5R

2

MC1R activation stimulates melanogenesis in melanocytes, increasing eumelanin production

3

MC4R activation in hypothalamic and limbic circuits enhances sexual arousal and desire

4

MC3R/MC4R activity in hypothalamic feeding centres contributes to appetite suppression

Contraindications

Do not use this peptide if any of the following apply:

  • History of melanoma or atypical mole syndrome
  • Cardiovascular disease or uncontrolled hypertension
  • Pregnancy or breastfeeding
  • Autoimmune conditions affecting skin pigmentation

Storage & Reconstitution

Unreconstituted (Powder)

Temperature2–8°C (36–46°F) or -20°C (-4°F) for long-term
DurationUp to 3 months

Reconstituted (Mixed)

Temperature2–8°C (36–46°F)
Duration2-4 weeks

Note: Protect from light. Do not freeze reconstituted solution.

Research Summary

Phase 1

Melanotan II was developed at the University of Arizona in the early 1990s as a photoprotective tanning agent. Phase I/II trials demonstrated effective tanning without UV exposure and revealed unexpected pro-sexual side effects, prompting development of the more selective PT-141. Due to its non-selective melanocortin activation and safety concerns around mole changes and melanoma risk, it has not pursued regulatory approval, though it remains widely available in research settings.

Frequently Asked Questions

Common questions about Melanotan II

UK-Specific Information

Exclusive data points and guidance for UK residents using Melanotan II

UK Lab Testing

UK Lab Testing

Recommended labs: Medichecks, Thriva (£89-£149 for peptide safety panel)

Why this matters: UK-specific lab testing guidance not available on US competitor sites

Commonly Stacked With

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