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Melanotan II

A synthetic melanocortin peptide studied for tanning, sexual function, and appetite suppression. Not FDA-approved; the FDA has issued public warnings against its use.

EmergingUse Caution

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This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician

What is Melanotan II?

Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH). It was originally developed at the University of Arizona as a potential sunless tanning agent. It activates melanocortin receptors broadly, which is why it affects multiple systems including skin pigmentation, sexual function, and appetite. The FDA has issued explicit warnings against the use of Melanotan II, citing safety concerns including unpredictable pigmentation changes, mole changes that may complicate skin cancer screening, and reports of serious adverse events. It is not recommended for any use outside of supervised research settings.

Why People Talk About It

Skin tanning without UV exposure

Emerging

Sexual function enhancement (PT-141/bremelanotide is the FDA-approved derivative for this use)

Emerging

Appetite suppression

Preliminary

How It Works

Melanotan II activates the same receptors that natural melanocyte-stimulating hormone uses. These receptors control skin pigmentation (tanning), sexual arousal, and appetite. Because it activates multiple receptor subtypes, it has broad effects — which is both its appeal and its risk.

Common Questions

Safety Information

Important Safety Notes

Common Side Effects

NauseaFacial flushingFatigueDarkening of molesNew mole formationSpontaneous erections

Cautions

  • FDA has issued warnings against use
  • May complicate skin cancer screening
  • Unpredictable pigmentation changes
  • Not approved for any medical use
  • Quality control concerns with unregulated sources

What We Don't Know

Long-term effects on melanocyte biology and skin cancer risk are not well characterized. This is a significant concern given the mechanism of action.

Published Research

31 studies

Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II

Clinical TrialPMID: 11035391

Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study

Clinical TrialPMID: 9679884

Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction

Clinical TrialPMID: 11018622

Nanostructured porous silicon microparticles enable sustained peptide (Melanotan II) delivery

Comparative StudyPMID: 20965250

The use of telemetry technology to test the proerectile effect of melanotan-II (MT-II) in conscious rats

Comparative StudyPMID: 15967265

Exploring the site of anorectic action of peripherally administered synthetic melanocortin peptide MT-II in rats

Comparative StudyPMID: 12834882

Extensive structure-activity studies of lactam derivatives of MT-II and SHU-9119: their activity and selectivity at human melanocortin receptors 3, 4, and 5

Comparative StudyPMID: 14531843

A comparison of HPLC and bioassay methods for plasma melanotan-II (MT-II) determination: application to a pharmacokinetic study in rats

Comparative StudyPMID: 7981427

Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review

ReviewPMID: 28266027

Changes in Oral Mucosa Associated with Melanotan II Injections: A Case Report

Case ReportPMID: 41752902

Melanotan II nasal spray: a possible risk factor for oral mucosal malignant melanoma?

Case ReportPMID: 40210573

The unregulated use of melanotan-II is of public health interest to Australian dermatologists

Case ReportPMID: 28905366

Eruptive naevi and darkening of pre-existing naevi 24 h after a single mono-dose injection of melanotan II

Case ReportPMID: 24334249

[Eruptive nevi after injection of drugs marketed as melanotan II. The first two Swedish cases described]

Case ReportPMID: 23451671

Melanotan II injection resulting in systemic toxicity and rhabdomyolysis

Case ReportPMID: 23121206

[Dermoscopic changes in melanocytic nevi during use of melanotan II]

Case ReportPMID: 23052015

Melanotan II: a possible cause of renal infarction: review of the literature and case report

Case ReportPMID: 31953620

5-Hydroxypyrroloindoline Affords Tryptathionine and 2,2'-bis-Indole Peptide Staples: Application to Melanotan-II

PreclinicalPMID: 38285527

Antidepressant-like and antistress effects of the ACTH(4-10) synthetic analogs Semax and Melanotan II on male rats in a model of chronic unpredictable stress

PreclinicalPMID: 39442746

Melanotan-II reverses memory impairment induced by a short-term HF diet

PreclinicalPMID: 37478579

CLIPSing Melanotan-II to Discover Multiple Functionally Selective hMCR Agonists

PreclinicalPMID: 35188390

Melanocortin receptor agonist melanotan-II microinjected in the nucleus accumbens decreases appetitive and consumptive responding for food

PreclinicalPMID: 36155088

LC-HRMS characterization of the skin pigmentation and sexual enhancers melanotan II and bremelanotide sold on the black market of performance and image enhancing drugs

PreclinicalPMID: 33245851

Melanotan II, a melanocortin agonist, partially rescues the impaired thermogenic capacity of pituitary adenylate cyclase-activating polypeptide deficient mice

PreclinicalPMID: 33332767

Combining MALDI mass spectrometry imaging and droplet-base surface sampling analysis for tissue distribution, metabolite profiling, and relative quantification of cyclic peptide melanotan II

PreclinicalPMID: 32674774

Melanotan-II reverses autistic features in a maternal immune activation mouse model of autism

PreclinicalPMID: 30629642

Melanotan II causes hypothermia in mice by activation of mast cells and stimulation of histamine 1 receptors

PreclinicalPMID: 29812984

Effect of Melanotan-II on Brain Fos Immunoreactivity and Oxytocin Neuronal Activity and Secretion in Rats

PreclinicalPMID: 28009464

Identification and characterization by LC-UV-MS/MS of melanotan II skin-tanning products sold illegally on the Internet

PreclinicalPMID: 24771717

Melanotan II User Experience: A Qualitative Study of Online Discussion Forums

Qualitative StudyPMID: 34464955

Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study

Clinical Trial, Phase IPMID: 8637402

Always consult a qualified clinician

This information is for educational purposes. Peptide therapy should be guided by a licensed healthcare provider. Connect with a Noho clinician

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Quick Facts

Class
Melanocortin Agonist
Evidence
Emerging
Safety
Use Caution
Updated
Jan 2026
Citations
31PubMed

Also known as

MT-IIMT2

Tags

SkinSexual WellnessAppetiteMelanocortin

Evidence Score

Overall Confidence35%

Clinical Trials

View Clinical Trials

Links to ClinicalTrials.gov for reference. Listing does not imply endorsement.

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