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Cosmetic & Dermal

Melanotan II Protocol

Dosing & Research

Last Updated: September 4, 2026

Chemical Identity
Amino Acid Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2
Molecular Formula
C50H69N15O9
Molecular Weight
1024.18 g/mol
CAS Number
121062-08-6

Tanning and melanocortin signaling, Libido research, Appetite suppression studies, Melanogenesis

Evidence Level
Mixed Evidence
Species Studied
Human • Rat • Mouse
Half-Life
~1 Hour
Administration
Subcutaneous
Frequency
Daily for 1 week (loading); 2x weekly (maintenance)

How It Works

  • Tanning and melanocortin signaling
  • Libido research
  • Appetite suppression studies
  • Melanogenesis

Dosing Structure

Dose
250 mcg
Frequency
Daily for 1 week (loading); 2x weekly (maintenance)
Notes
Loading (week 1): Start At 50mcg/Day And Titrate Up To 200mcg/Day Based On Tolerance. Adjust Based On Pigment Changes. Maintenance: 50–100mcg 2x Per Week. Metabolic Support: 50mcg Per Day, Expect Some Pigmentation. Cycle: 4–6 Weeks With 4 Week Minimum Break. Do Not Stack With Melanotan I. Do Not Use If At Risk Of Melanoma Or Other Skin Cancer. Inject: Abdomen (preferred), Thigh, Upper Arm. Break: 4 Weeks Minimum.

Example Protocols

Dose: 250 mcg
Frequency: Daily for 1 week (loading); 2x weekly (maintenance)
Duration: 6-8 weeks
Off Period: Not listed
Calculate dosing →

Find Research Grade Melanotan II

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Protocol Notes

•
Loading (week 1): Start at 50mcg/day and titrate up to 200mcg/day based on tolerance.
•
Adjust based on pigment changes.
•
Maintenance: 50–100mcg 2x per week.
•
Metabolic Support: 50mcg per day, expect some pigmentation.
•
Cycle: 4–6 weeks with 4 week minimum break.
•
Do not stack with Melanotan I.
•
Do not use if at risk of melanoma or other skin cancer.
•
Inject: Abdomen (preferred), thigh, upper arm.
•
Break: 4 weeks minimum.

What Is Melanotan II?

Melanotan II (MT-II) is a non-selective synthetic melanocortin agonist that simultaneously activates multiple melanocortin receptors: MC1R (pigmentation), MC3R and MC4R (sexual function, appetite, energy homeostasis). It produces robust skin tanning without UV exposure, potent pro-erectile effects, appetite suppression, and a range of CNS effects. It is not approved by any regulatory body and is sold exclusively as a research chemical.

Research Observations - Not Medical Claims
  • ▸Tanning: MT-II at 0.025 mg/kg SubQ produced darkening across all skin phototypes; Type I subjects showed the most dramatic melanin response. Tanning appeared within 5–10 days without UV exposure (PMID: 9665198).
  • ▸Erectile function: Phase 1 data showed 17 of 19 men with psychogenic ED achieved erections after MT-II 0.025 mg/kg SubQ - with a median latency of ~25 min post-injection (PMID: 8641826).
  • ▸Appetite suppression: MT-II activates MC4R, which powerfully suppresses appetite and increases energy expenditure - researchers use this to model MC4R biology in metabolic disease.
  • ▸Spontaneous erections: The most reported side effect at research doses - prominent and dose-dependent activation of MC4R in spinal and limbic circuits produces erections without sexual stimulation.
  • ▸PT-141 derivation: PT-141 (bremelanotide, FDA-approved) was developed from MT-II by removing the lactam ring - retaining MC4R sexual effects while eliminating some melanin-activating activity.

Evidence Summary

Mixed EvidenceNot approved by any regulatory authority - Research Chemical only
Evidence StrengthPreliminary
PreliminaryModerateStrong
Curated Citations2
Largest Study (n)20
Most Recent Study2023
Species Studied
HumanRatMouse

Commonly Researched With

PT-141
PT-141 is derived from MT-II with a more selective profile - researchers compare outcomes between these two melanocortin agonists.
Melanotan I
Melanotan I is the MC1R-selective variant - researchers compare specificity, side effects, and tanning outcomes between MT-I and MT-II.
GHK-Cu
GHK-Cu's collagen and skin quality effects are sometimes studied alongside melanocortin-mediated tanning in dermal research protocols.

Research & Studies

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