MT-2 · MT2 · Melanotan II · Melanotan 2
Melanotan II (MT-II) is a synthetic cyclic heptapeptide analog of alpha-melanocyte stimulating hormone (alpha-MSH) that activates melanocortin receptors (MC1R through MC5R) with broad affinity. Its cyclic disulfide bridge structure (between positions 4 and 10) enhances stability and receptor binding compared to linear alpha-MSH. MT-II stimulates melanogenesis (skin darkening via melanocyte activation), suppresses appetite, and enhances sexual arousal through central melanocortin signaling. The tanning effect occurs with or without UV exposure but is significantly enhanced by sun/UV. MT-II is used at very low doses (100-250 mcg) and requires solo administration due to its complex receptor pharmacology.
Evening dosing before bed. Loading phase first (1-2 weeks daily), then maintenance 2x/week. Nausea common initially - start low.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
MT-II binds melanocortin receptors throughout the body. MC1R activation on melanocytes stimulates melanogenesis (eumelanin production), darkening skin and providing UV protection. MC3R and MC4R activation in the hypothalamus suppresses appetite and enhances sexual arousal and erectile function. The cyclic disulfide bridge between Cys4 and Cys10 constrains the peptide into a bioactive conformation with enhanced receptor binding affinity and enzymatic stability compared to linear MSH analogs. Effects on pigmentation are cumulative and persist for weeks after discontinuation due to melanin turnover kinetics.
Days 1-7: Nausea and facial flushing after injection. Mild skin darkening may begin. Libido enhancement possible within first few doses.
Weeks 2-4: Significant skin darkening, especially with UV exposure. Appetite suppression. Sexual function enhancement established.
Weeks 4+: Maintenance phase. 1-2x weekly dosing sustains pigmentation. Monitor moles. Color fades over 4-8 weeks if discontinued.
Each reference below was re-fetched from its PubMed record, and the quoted sentence was confirmed to appear in that abstract and to support the claim it sits under. Follow any of them to read the source.
Evidence boundary from the checked abstract: In the absence of sexual stimulation, Melanotan II led to penile erection in 17 of 20 men.
In the absence of sexual stimulation, Melanotan II led to penile erection in 17 of 20 men.
Evidence scope. This entry supports only the exact statement quoted from the live abstract; it does not independently verify OnePin's displayed dose, route, frequency, formulation, population, or broader mechanism.
Claims we could not support
No abstract we checked supports these for this molecule at this route. That is not the same as saying they are false — it marks where the evidence is missing.
Dose/route: 100-250 mcg; SubQ injection; 1-2 times weekly for maintenance. No checked live PubMed abstract verified this exact displayed dose, route, and frequency for the same molecule/formulation and relevant population.
Primary safety claim: No primary safety text present in source JSON. No checked live PubMed abstract directly verified this source-JSON safety claim at the displayed formulation, route, and regimen.
Tanning without UV
Confirmed. MT-II increases melanin production independent of UV exposure. UV exposure accelerates and enhances the effect but is not required.
Confirmed in human studies. MC3R/MC4R activation in hypothalamus enhances libido and erectile function. PT-141 (Bremelanotide) was derived from MT-II and is FDA-approved for this purpose.
MT-II stimulates all melanocytes including those in moles. New mole formation and darkening of existing moles is documented. Direct melanoma causation is not proven but theoretical risk warrants monitoring.
Two different questions: what is documented about running these together, and what is documented about drawing them into the same syringe. A good pharmacological partner can still have to be pinned separately.
Check any specific pair in the Stack & Interaction Checker, which answers both questions separately. Absence of a documented conflict is not evidence of safety.
SubQ
(acute effects); melanogenesis persists for days to weeks
Enzymatic degradation (peptidases); cyclic structure slows degradation
Storage. Cyclic disulfide bridge provides enhanced stability. 28-42 day reconstituted shelf life at 2-8C. Small doses mean vials last many weeks. Protect from light. Do not freeze after reconstitution.
Not FDA-approved. PT-141 (derived from MT-II) is FDA-approved for HSDD. WADA prohibited under S2. Available through research and compounding channels. Multiple countries have issued warnings about unregulated MT-II use.
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Open MT-II straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.
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