What is the half-life of Melanotan II?

Melanotan II has a half-life of ~1 hour, which is why it's typically administered initially daily for loading, then 1-2 times weekly for maintenance for optimal therapeutic effect.

How do I reconstitute Melanotan II?

Add bacteriostatic water to the peptide vial slowly down the side. Typical reconstitution uses 2-3ml of water for a 5mg vial. Gently swirl, do not shake.

Healing & Recovery

Phase 1

Melanotan II

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

Overview

Key Facts

Primary Goal: A synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that activates multiple melanocortin receptors

A synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that activates multiple melanocortin receptors. Originally developed for skin tanning, it was found to produce significant pro-sexual effects, leading to the development of PT-141 (bremelanotide) as a more targeted derivative. 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

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

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.