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Melanotan II

Cyclic synthetic alpha-MSH analogue and melanocortin receptor agonist

Melanocortin-agonist research focused on pigmentation, with additional effects on sexual function observed.

Limited Human Evidence

Route

Subcutaneous research use.

Common format

10 mg vial

Research focus

melanogenesis

Evidence level

Limited Human Evidence

Typical cycle

6–8 weeks (loading)

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Melanotan II in 30 seconds

Atlas Fast Read

What it is

Cyclic synthetic alpha-MSH analogue and melanocortin receptor agonist

Why people care

Melanocortin-agonist research focused on pigmentation, with additional effects on sexual function observed.

Human evidence

Limited Human Evidence — Human interventional or clinical data exist, but studies are small, early-phase, mixed, indirect, route-specific, or not confirmatory.

Biggest misconception

Key gaps include larger independent trials, clearer dose-response data, long-term safety, clinically meaningful endpoints, and evidence that findings generalize beyond the narrow populations or routes already studied.

Bottom line

Melanotan II has a real human signal or documented human pharmacology, but evidence is too small, mixed, route-specific, or indication-specific to justify broad claims.

Overview

What is Melanotan II?

Melanotan II is cyclic synthetic alpha-MSH analogue and melanocortin receptor agonist. Melanocortin-agonist research focused on pigmentation, with additional effects on sexual function observed.

Melanotan analogues were developed from alpha-MSH research at the University of Arizona in the 1980s–1990s. Melanotan II was investigated for pigmentation and sexual effects but was never approved as a tanning drug.

Mechanism

How it works

Activates multiple melanocortin receptors, especially MC1R for melanogenesis and central MC3R/MC4R pathways that influence appetite and sexual arousal. Its broad receptor activity explains both desired and adverse effects.

Research areas

melanogenesissexual arousalappetitemelanocortin biology

Evidence

What does the evidence actually say?

Limited Human Evidence

Human interventional or clinical data exist, but studies are small, early-phase, mixed, indirect, route-specific, or not confirmatory.

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Preclinical Evidence

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Limited Human Evidence

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Strong Human Evidence

Human evidence

Small human studies demonstrated melanogenesis and sexual effects, but Melanotan II was never approved as a tanning or sexual-health drug. Unregulated use has outpaced the quality of controlled long-term safety data.

Preclinical evidence

Animal and early human pharmacology established broad melanocortin-receptor agonism affecting pigmentation, appetite, and sexual behavior. Preclinical data also explain cardiovascular and autonomic side effects.

Knowledge gaps

Key gaps include larger independent trials, clearer dose-response data, long-term safety, clinically meaningful endpoints, and evidence that findings generalize beyond the narrow populations or routes already studied.

Protocol

Research protocol

DoseFrequencyTimingCycle

Dose

Community research reference: 250 mcg/day titrating to 1 mg/day during loading, then 0.5–1 mg one to two times weekly for maintenance. There is no approved tanning dose.

Frequency

Daily during loading; 1–2 times weekly maintenance in the community protocol.

Timing

Timing relative to UV exposure is commonly discussed but not clinically validated; UV exposure itself carries cancer risk.

Route

Subcutaneous research use.

Cycle length

6–8 weeks (loading)

Reconstitution

Community reference: 1 mL bacteriostatic water per 10 mg vial = 10 mg/mL.

Storage

Community reference: lyophilized frozen; reconstituted 2–8 °C and use within 1–2 weeks.

Monitoring

Blood pressure, nausea, sexual side effects and careful skin/mole surveillance. New or changing pigmented lesions require clinical evaluation.

Protocols vary widely between sources. Investigational compounds are not approved therapies, and approved products should follow their official labeling. Nothing here is medical advice.

Safety

Safety, side effects, and precautions

Side effects

Reported effects include nausea, flushing, appetite suppression, spontaneous erections/increased libido, fatigue, headache and darkening of freckles/moles. Priapism and concerning pigment changes are important red flags.

Contraindications

No approved contraindication profile exists. Avoid in pregnancy/breastfeeding and use particular caution with melanoma/atypical-nevus history, uncontrolled cardiovascular disease or priapism risk.

Interactions

Formal interaction studies are lacking. Additive blood-pressure/autonomic effects with vasoactive drugs and additive sexual effects with erectile-dysfunction therapies are plausible concerns.

Stacks

Common stacks

No well-supported stack is highlighted for this peptide yet.

Questions

FAQ

References

Sources

Atlas

The Atlas verdict

Melanotan II has a real human signal or documented human pharmacology, but evidence is too small, mixed, route-specific, or indication-specific to justify broad claims. The most defensible use of the literature is to separate what has actually been measured in people from what is still extrapolated from mechanism or animal work.

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