Melanotan II
Synthetic analog of α-melanocyte-stimulating hormone (α-MSH). Binds melanocortin receptors (notably MC1R for tanning and MC4R for sexual function). Originally researched for therapeutic skin pigmentation; abandoned in clinical development. Sold heavily as a grey-market 'tanning peptide.' Significant safety concerns — Class A action by some regulators.
Educational only — not medical advice. SmartPeptide does not prescribe, diagnose, or treat. Always consult a licensed healthcare provider before using any peptide, supplement, medication, or protocol.
What the research shows
Demonstrated melanocortin receptor agonism and skin pigmentation effects in human research. Clinical development as a therapeutic was abandoned due to side-effect profile. Multiple case reports link Melanotan II use to new or atypical melanocytic lesions — causation debated but signal exists.
What's still experimental
Use is entirely outside FDA-approved channels. Long-term cancer-risk profile is unclear but the mole-darkening / new-mole signal is concerning.
Anecdotal / community reports
Heavy 'tanning enhancement' use. Users routinely report side effects (nausea, mole changes) that align with the published case-report literature.
Anecdotal reports are NOT scientific evidence. They reflect personal experience and may not generalize.
FDA approval status
Source: openFDA + DailyMed (NIH/NLM)Doses studied in research
No established dose rangeWhat published trials tested or FDA-approved labels specify. Reporting research facts — not a SmartPeptide recommendation.
This is the honest answer for peptides like BPC-157, IGF-1 LR3, MOTS-c, Epitalon and similar research compounds — robust human dose- ranging studies have not been published. Always work with a licensed clinician familiar with experimental peptides if you are considering any use.
FDA enforcement & recalls
Live · openFDA Drug Enforcement API- Class IITerminated· Voluntary: Firm initiatedFDA record
Melanotan II 1 mg/mL (10 mL) Injection, 10mL vials, Rx only, Farmakeio 1736 N Greenville Ave Richardson, TX 75081 USA
Reason: Lack of Assurance of Sterility: deviations from Current Good Manufacturing Practices (CGMP) that call into question the sterility of products intended to be sterile.
Apr 5, 2022·North American Custom Laboratories, LLC dba FarmaKeio Superior Custom Compounding - Class IITerminated· Voluntary: Firm initiatedFDA record
Melanotan II, 10mg injection, Rx Only, Promise Pharmacy Compounding Specialists 31818 US Hwy 19N, Palm Harbor, FL 34684
Reason: Lack of sterility assurance.
Dec 17, 2018·Promise Pharmacy, LLC
Mechanism & targets
ChEMBL · UniProt · Open TargetsMolecule (ChEMBL)
View on ChEMBLProtein targets (UniProt)
- Melanocortin receptor 4P32245gene: MC4RHomo sapiens· 332 aaReviewed
G protein-coupled receptor that binds melanocyte-stimulating hormones (alpha- and beta-MSH) and corticotropin/ACTH, which are peptide products of the POMC precursor (PubMed:12646665, PubMed:14764818, PubMed:25163632, PubMed:32327598, PubMed:33858992, PubMed:8392067). Functions as a central component of the leptin-melanocortin pathway, which is essential for maintaining energy homeostasis (PubMed:32327598, PubMed:33858992). Upon activation, couples to G(s) protein, stimulating adenylate cyclase a…
Live research
PubMed · ClinicalTrials.gov · Europe PMC · OpenAlexClinical trials (ClinicalTrials.gov)
- Melanotan II (MT-II) as an Adjunct to NB-UVB Phototherapy for Repigmentation in Stable Nonsegmental VitiligoRECRUITINGNCT07437560 · PHASE2 · n=60 · 2026-02-02
Europe PMC — 754 additional records
Includes EU/UK studies and PubMed Central full-text articles. Often surfaces research weeks before PubMed indexes it.
- Five primary melanomas in situ in a patient with recent tanning bed use, melanotan exposure, and anabolic hormone useVadner DJ, Smith S. · 2026Open access
- Injuries, Injections, and Internet Forums: A Qualitative Study of Reddit User Perspectives on Peptide Therapy After Orthopaedic SurgeryRosenberg AE, Taylor B, Rasquinha RD, et al. · 2026
- Neural Melanocortin Receptors in Fish: Insights into Growth Regulation and Aquaculture Advancement· 2026Open access
- Discovery of TYR inhibitors from de novo molecular generation to dual-track lead optimization: "Competition" between AI and chemistsSun Y, Wang J, Chen W, et al. · 2026Open access
Research volume (OpenAlex topic graph)
Human clinical evidence
Semantic Scholar · AI TLDRs · influence-rankedHuman-study summaries for “melanotan II OR melanotan-II” are available on Semantic Scholar but the shared free-tier API quota is exhausted right now. Try refreshing in a few minutes, or check the PubMed and Europe PMC panels above for the same literature.
Research funding & verification
NIH RePORTER · CrossRef DOI registryNIH-funded research
U.S. National Institutes of Health- 5P50MH100023-10$858KOxytocin-dependent Social Salience Network Activity evoked by targeting melanocortin receptorsLarry J Young · EMORY UNIVERSITY · FY2022
- 5R01HL163076-03$588KCardiac protective mechanisms of melanocortin system activationJussara M. Do Carmo · UNIVERSITY OF MISSISSIPPI MED CTR · FY2025
- 1R01HL163076-01A1$586KCardiac protective mechanisms of melanocortin system activationJussara M. Do Carmo · UNIVERSITY OF MISSISSIPPI MED CTR · FY2023
- 5R01HL163076-04$576KCardiac protective mechanisms of melanocortin system activationJussara M. Do Carmo · UNIVERSITY OF MISSISSIPPI MED CTR · FY2026
Publication landscape
CrossRef · DOI registry- National Natural Science Foundation of China23,013 works
- National Science Foundation3,676 works
- National Institutes of Health2,723 works
- National Key Research and Development Program of China2,384 works
- Deutsche Forschungsgemeinschaft2,342 works
- Japan Society for the Promotion of Science2,287 works
Funder diversity is a credibility signal. Research concentrated in a single drug company's funding warrants more scrutiny than research funded across NIH, charities, and academic grants.
Preprints — cutting edge
bioRxiv · medRxiv · via Europe PMCPreprints have NOT been peer-reviewed. They are early research shared by authors before formal validation. Treat findings as preliminary.
- PreprintMelanocortin receptor agonist melanotan-II microinjected in the nucleus accumbens decreases appetitive and consumptive responding for foodEliason N, Martin L, Low MJ, et al. · 2022-04-14
- PreprintHypothalamic C2-domain protein involved in MC4R trafficking and control of energy balanceGavini CK, Cook TM, Rademacher DJ, et al. · 2019-10-03
Known risks
Nausea (very common during dosing), spontaneous erections, darkening + emergence of new moles (concerning melanoma signal), blood pressure changes, facial flushing. The FDA has issued warnings against MT-II. Source quality is highly variable.
Reported side effects
Nausea (common, often dose-limiting), flushing, decreased appetite, darkening of existing moles, new mole formation, spontaneous erections, headache, fatigue.
FDA adverse event reports (FAERS)
Updated quarterly by FDA- AU4
- SE3
Most-reported reactions
- Renal Artery Thrombosis5
- Renal Infarct3
Counts from FDA Adverse Event Reporting System (FAERS). Voluntary reports — they show what was reported, not whether the drug caused the event. Many reports lack confirmation. FAERS docs
What requires medical supervision
FDA has explicitly warned against. Dermatologic monitoring is critical for anyone who has used it — annual full-body skin checks. Discuss with a dermatologist who knows the literature.
Questions for your clinician
- I've used / am considering Melanotan II — when should I get a baseline full-body skin check?
- What's the rational alternative for sun protection / pigmentation concerns?
- Are there warning signs in my moles I should watch for?