Melanotan II Guide

Melanotan II at a glance

What it is

Synthetic cyclic heptapeptide, a non-selective melanocortin receptor (MC1R–MC5R) agonist

Researched for

Melanogenesis (skin pigmentation) in early research; MC4R-linked effects on libido and appetite reported

Commonly reported range

~250–500 mcg per dose in community reports

Route reported

Subcutaneous injection

Reported frequency

Daily during a loading phase, then 1–3x weekly for maintenance

Reported cycle

~1–2 week loading, then intermittent maintenance in community protocols

Plasma half-life

Reported short, roughly 30 minutes to ~1 hour

Regulatory status

Not FDA-approved for any use; sold as research-only; unapproved in US/UK/EU

Reported ranges from research/community — examples, not recommendations.

What it is / mechanism

Melanotan II is a synthetic cyclic analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts as a non-selective agonist across the melanocortin receptor family (MC1R through MC5R). Its best-characterized action is at MC1R on melanocytes, where receptor activation raises intracellular cyclic AMP and upregulates tyrosinase, the rate-limiting enzyme of melanin synthesis, in reported research this drives increased eumelanin production and skin darkening. Because it is non-selective, it also engages MC3R and MC4R in the central nervous system, and this MC4R activity is the reported basis for the appetite-suppressing and sexual-arousal effects that distinguish it from the more MC1R-selective afamelanotide (Melanotan I). The related fragment bremelanotide (PT-141) was developed specifically around this MC4R sexual-response pathway. These are described mechanisms from preclinical and early research, not established therapeutic outcomes.

Researched effects

In research and community reports, Melanotan II is associated with increased skin pigmentation (tanning) with reduced UV exposure, and, via central melanocortin activity, reported appetite suppression and increased sexual arousal. These are research findings and community-reported observations, not guaranteed outcomes, and human data are limited and largely uncontrolled. Individual responses reportedly vary widely with skin type, dose, and UV exposure.

Dosage — reported ranges (overview)

The figures below are examples of what is reported in community protocols and vendor literature, not a recommendation and not a personal dose. Reported protocols commonly describe a loading phase of roughly 250 mcg per subcutaneous dose daily for about 1–2 weeks, sometimes titrated toward 500 mcg if tolerated, followed by a maintenance phase of about 500 mcg one to three times per week. Because MT-II can cause nausea and other effects, community reports frequently mention starting low. These are descriptions of reported practice for educational context only.

The full step-by-step protocol examples, titration, and printable protocol sheet are planned for a future paid Protocol Playbook module.

Reconstitution — bac-water math

Melanotan II ships as a lyophilized powder that is reconstituted with bacteriostatic water and measured on a U-100 insulin syringe, where 100 units = 1 mL. For a mcg-dosed peptide, the key figure is concentration in mcg/mL: with a V-mg vial and W mL of water, concentration = (V x 1000) / W mcg/mL, and the units to draw for a dose of D mcg = round(D / concentration x 100). Worked example: a representative 10 mg vial reconstituted with 2 mL of bacteriostatic water gives (10 x 1000) / 2 = 5,000 mcg/mL; a 500 mcg example dose is then 500 / 5000 x 100 = 10 units on a U-100 syringe. This is concentration math only, not a personal dose.

This is concentration math, not a dose recommendation.

Injection / administration basics

In reported protocols, Melanotan II is administered subcutaneously using a small insulin syringe, typically into the fat of the abdomen with the site rotated between injections. Bacteriostatic water is the commonly described diluent, added slowly against the vial wall rather than directly onto the powder, and the vial is gently swirled rather than shaken. This describes reported handling practice for research context and is not medical or administration advice.

Half-life & frequency rationale

Melanotan II is reported to have a short plasma half-life, with sources citing roughly 30 minutes to about 1 hour. This short duration is the reason daily dosing appears in loading-phase community protocols, while the pigmentation effect itself is reported to persist much longer because melanin, once produced, remains in the skin.

Stacking — overview

Because it is non-selective across melanocortin receptors, Melanotan II is most often discussed in the community alongside compounds that target overlapping pathways or complementary goals. The pairings below reflect commonly reported combinations for educational context only, not recommendations, and combining unapproved compounds adds unknown risks.

Storage & handling

• Lyophilized (powder): store sealed and protected from light; refrigeration is commonly recommended, and cool freezer storage is reported for long-term stability before reconstitution.
• Reconstituted (in bacteriostatic water): keep refrigerated (about 2–8 C), protect from light, and use within a few weeks per common handling guidance.

Guide FAQ

Quick answers about guide scope, access, and educational use context.