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Sexual Health

Melanotan II peptide reference

Melanocortin agonist used for tanning and libido. Significant safety concerns.

Last reviewed May 6, 2026 Human data Not FDA approved
Peppi reviewing Melanotan II notes
Default dose label500 mcg
Preferred routeSubQ
Frequency labelDaily during loading, then 1–2× weekly maintenance
Storage window30 days mixed

Evidence snapshot

Human data

Evidence maturityHuman data
Limited human studies; not approved for human use anywhere

Research chemical / banned in many jurisdictions

Route map

How records are usually labeled

1 SubQ

Rotate sites — repeated injection in one area can cause local hyperpigmentation.

Vial timeline

Storage cues to log

Before mixRefrigerate 2–8 °C; freeze long-term.
After mixRefrigerate 2–8 °C, use within 30 days.
Use-by cue30 days after mixing
Mixed vial window30 days
Use this as a record-keeping cue, not a replacement for product labeling.

Peppi workflow

From vial to review

Vial 10 mg vial
Dose 500 mcg
Route SubQ
Review 30d storage

Peppi turns scattered dose, vial, route, storage, note, and report details into one record trail.

Educational reference only

This page helps you understand what to track for Melanotan II. It is not medical advice, a prescription, or a recommendation to use this peptide. Discuss dose, route, timing, storage, and safety with a qualified healthcare professional.

Overview

Melanotan II is a synthetic cyclic heptapeptide and non-selective melanocortin receptor agonist. Originally developed at the University of Arizona in the 1980s as a sunless tanning agent, it activates MC1R for melanin production and MC4R for sexual response. It is not approved by the FDA or any major regulator — sold as research-only in most jurisdictions, with notable safety concerns including mole darkening and possible melanoma risk.

Also known as: MT-II, MT2.

Cosmetic tanning enhancementLibido researchErythropoietic protoporphyria research (related: afamelanotide / Scenesse)

Mechanism and timing snapshot

Non-selective MC1R/MC3R/MC4R/MC5R agonist. MC1R activation drives melanogenesis; MC4R drives appetite suppression and sexual response.

Onset label30 min
Catalog onset field, when available.
Half-life label1 hr
~33–60 min plasma half-life
Duration label6 hr
Catalog duration field, when available.
subQ High
oral Negligible

Tracking defaults

These values come from Peppi's catalog so records can be prefilled consistently. They should be reviewed against your clinician's instructions before logging real-world use.

Catalog default dose500 mcg
Catalog dose range250 mcg - 1 mg
Default routeSubQ
Frequency labelDaily during loading, then 1–2× weekly maintenance
Best time labelEvening before bed (nausea typically peaks 30–60 min after dosing).
Food noteNone significant; appetite suppression is a normal effect.

Catalog protocol note

Loading: 250–500 mcg subQ daily until desired tan develops (typically 2–3 weeks). Maintenance: 500 mcg 1–2× weekly with sun exposure.

Routes and site notes

Available route labelsSubQ
Preferred route labelSubQ
Common site labelsAbdomen, Thigh
Site rotation noteRotate sites — repeated injection in one area can cause local hyperpigmentation.

Chemistry

SequenceAc-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Amino acids7
Molecular formulaC50H69N15O9
Molecular weight1024.18 Da

Vial, reconstitution, and storage

Supply formLyophilized powder
Typical vial size10 mg
DiluentBacteriostatic water
Diluent volume2 mL
Concentration note10 mg in 2 mL → 0.10 mL = 500 mcg (10 units on a 100-unit insulin syringe).
Before reconstitutionRefrigerate 2–8 °C; freeze long-term.
After reconstitutionRefrigerate 2–8 °C, use within 30 days.
Reconstituted shelf life30 days
Light sensitiveYes
Freeze/thaw warningYes

Safety notes

Common and rare side effects listed in the catalog

  • Nausea (~50% first doses)
  • Facial flushing
  • Spontaneous erections in men
  • Decreased appetite
  • Yawning
  • Darkening or new moles
  • Atypical melanocytic lesions
  • Priapism (medical emergency)
  • Blood pressure changes

Contraindications and warnings

  • Personal/family history of melanoma
  • Atypical mole syndrome
  • Pregnancy
  • Pre-existing darkly pigmented skin (less needed and harder to gauge)
  • Multiple case reports of melanoma diagnoses in users.
  • Have any new or changing moles examined by a dermatologist promptly.

Other considerations

  • Check moles before starting and every 3–6 months while using.
  • Tolerance to nausea develops over the first few doses.
  • Sunscreen use is still essential — tanning effect does not equal UV protection.

Evidence and regulatory context

Evidence levelLimited human studies; not approved for human use anywhere
FDA approvedNo
Regulatory statusResearch chemical / banned in many jurisdictions
Prescription requiredNo
Approved countriesNot listed

Stacking and cycle notes

Stacks well withNot listed
Avoid combining notePT-141 (redundant melanocortin activity)
Typical cycle label2–3 (loading)
Typical break labelContinuous low-dose maintenance, or off-cycle in winter
Cycle guidanceFront-load to desired tan, then taper to maintenance with sun exposure. Consider seasonal cycling.

Tracking tips

  • Photograph existing moles before starting and compare every 3 months.
  • Start with very low doses (100 mcg) to gauge nausea before scaling up.
  • If you develop priapism (>4h erection), seek emergency care.

References

Track it in Peppi

Keep Melanotan II records organized.

Use Peppi for dose logs, vial inventory, storage dates, reminders, journal notes, photos, and clinician-ready reports.

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FAQ

What should I track for Melanotan II?

Track the peptide name, dose amount and unit, route, vial label, timing, reconstitution or expiration dates, storage notes, and any symptoms or questions for clinician review.

Does Peppi tell me how to use Melanotan II?

No. Peppi organizes educational reference and your own records. Protocol decisions should come from a qualified healthcare professional.

Can I export Melanotan II records?

Peppi is designed to keep dose logs, vial inventory, journal notes, and reports easier to review and export.

Last reviewed: May 6, 2026