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SkinUnapproved — safety warnings issuedLimited human evidence

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)
No FDA-approved drug label exists for “Melanotan II”. This peptide is not currently approved by the FDA as a finished pharmaceutical product. Any commercial product claiming FDA approval should be treated with suspicion.

Doses studied in research

Source: Published clinical trial

What published trials tested or FDA-approved labels specify. Reporting research facts — not a SmartPeptide recommendation.

⚠ HAZARD WARNING — read before considering doses below

FDA HAS ISSUED WARNINGS AGAINST SELLING MELANOTAN II. Multiple peer-reviewed case reports link MT-II use to new or atypical melanocytic lesions (potential melanoma signal). Any prior or current use should prompt a baseline full-body dermatology check + annual follow-up. SmartPeptide displays this data only for harm-reduction (people will use it regardless) and strongly advises consulting a dermatologist who knows the published case-report literature.

Community-anecdotal range — NOT a SmartPeptide recommendation

The doses below are aggregated from research-peptide community forums (Reddit, biohacker discussions). They are NOT supported by clinical trials, NOT FDA-approved, and NOT a SmartPeptide recommendation. Source purity, dose accuracy, and user-reported outcomes are unverifiable. We display this only because the information is publicly available elsewhere — visitors should absolutely consult a licensed clinician familiar with experimental peptides before any use.

Community-anecdotal — not evidence-basedTanning / 'optimization' community forums (FDA HAS WARNED AGAINST)
Indication studied: Community-discussed for skin pigmentation (FDA has issued warnings against)
Loading
250µg
daily during 1-2 week loading · subcutaneous

Most-discussed loading phase

Open calculator
Maintenance
500µg
2-3x per week after loading · subcutaneous

Most-discussed maintenance

Open calculator

Notes from the source: Heavy nausea is the most common reported effect. Spontaneous erections, blood pressure changes, and headache are also common.

Important framing: The numbers above are what published trials tested or what FDA-approved labels specify. They are NOT a SmartPeptide recommendation for you. Trial doses come paired with screening, monitoring, and clinician oversight. Always consult a licensed clinician before any peptide use.

How clinicians typically protocol this

Third-party reference · not our recommendation

Dosing phases, cycle lengths, and administration timing as listed in a compounding-pharmacy clinician reference guide. Shown so you can see what a real protocol looks like — and bring informed questions to a licensed clinician.

Third-party protocol referenceCompounding-pharmacy clinician protocol reference (Nov 2025)

Dose numbers, frequencies, and cycle lengths in this panel are extracted from a clinician-facing reference protocol distributed by a US-based compounding pharmacy in November 2025. SmartPeptide has paraphrased all descriptive text and adds no endorsement. Always consult a licensed clinician.

Additional caution for Melanotan II

FDA has warned against Melanotan II. Case reports link use to darkening/changes of moles and melanoma. See hazard warning above.

Aesthetic

Cyclic α-MSH analog activating MC1R–MC5R; the reference lists this for pigmentation and libido effects.

Protocol phases

Loading
0.25–0.5 mgdaily × 5–10 days
subcutaneous

or until desired pigmentation

Maintenance
0.5–1 mgper week (may split into 2 injections)
subcutaneous
Reported side effects
NauseaFlushingIncreased libidoUneven color in some users
Reconstitution calculator Storage & reconstitution guide
Not medical advice. SmartPeptide does not prescribe, diagnose, or treat. The protocol above reproduces dose figures from a third-party clinician reference so you can see what compounding-pharmacy guidance typically looks like — it is not a recommendation for you, and it has not been validated against peer-reviewed dose-ranging trials. Many of these compounds are not FDA-approved for human use. Work with a licensed clinician familiar with peptide therapy before considering anything here.

FDA enforcement & recalls

Live · openFDA Drug Enforcement API
Total actions
2
recalls + withdrawals
Ongoing
0
not yet completed
Class I (serious)
0
health hazard / death risk
  • Class IITerminated· Voluntary: Firm initiated
    FDA 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 initiated
    FDA 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
FDA classifications: Class I = reasonable probability of serious adverse health consequences or death. Class II = temporary or medically reversible adverse consequences. Class III = unlikely to cause adverse health consequences.

Mechanism & targets

ChEMBL · UniProt · Open Targets

Molecule (ChEMBL)

View on ChEMBL
Formula
C50H69N15O9

Protein targets (UniProt)

  • Melanocortin receptor 4
    P32245gene: 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 · OpenAlex
PubMed papers
242
total
Human studies
0
MeSH: humans
Clinical trials
0
published
Active trials
1
1 total registered

Europe PMC — 759 additional records

Includes EU/UK studies and PubMed Central full-text articles. Often surfaces research weeks before PubMed indexes it.

Human clinical evidence

Semantic Scholar · AI TLDRs · influence-ranked
Semantic Scholar API is currently rate-limited.

Human-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 registry

NIH-funded research

U.S. National Institutes of Health
Funded projects
41
all years
Top award sum
$11.4M
aggregate USD
Years covered
19
research span
Largest active / recent grants

Publication landscape

CrossRef · DOI registry
Indexed works (CrossRef)
1,860,494
all DOIs registered
Retracted papers
0
no retractions on record
Top funders of indexed research
  • National Natural Science Foundation of China23,412 works
  • National Science Foundation3,716 works
  • National Institutes of Health2,736 works
  • National Key Research and Development Program of China2,449 works
  • Deutsche Forschungsgemeinschaft2,363 works
  • Japan Society for the Promotion of Science2,326 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 PMC

Preprints have NOT been peer-reviewed. They are early research shared by authors before formal validation. Treat findings as preliminary.

Showing 2 of 2 preprints indexed by Europe PMC.

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
Reports filed
9
FAERS, all years
Serious reports
8
89% of reports
Top reporting countries
  • AU4
  • SE3

Most-reported reactions

  • Renal Artery Thrombosis
    5
  • Renal Infarct
    3
  • Melanocytic Naevus
    1
  • Product Advertising Issue
    1
  • Product Use Issue
    1
  • Skin Texture Abnormal
    1

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?

Editorially curated references

Discussions about Melanotan II

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