MT-2

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Also seen as: Melanotan II, melanotan 2

The Dose Guy’s verdict

Sep 1, 2026
3 sources

MT-2 works. A small dose tans you from the inside, real melanin, and the community has been running it for well over a decade. The trade is real too: new moles and darkening freckles, a pigment system you are actively pushing. Run it low, skip the loading protocols, and keep tabs on your skin. At a sensible dose the tan is worth it.

Would I take it?Yes, and I do. Keep the dose low.

What it is

A cyclic peptide that mimics alpha-MSH, your body’s tanning signal. MT-2 binds melanocortin receptors on melanocytes and tells them to produce melanin, the same pathway the sun triggers, just fired from below the skin instead of above. The tan is real pigment, not a dye, and it builds over the first few weeks with some UV exposure.

MT-2 is non-selective, meaning it hits melanocortin receptors beyond MC1R. The MC4R hit is why it raises libido and can trigger spontaneous erections, the same receptor PT-141 works through. MT-1 is the linear analog, designed to tan without the off-target effects, but in practice the selectivity mostly means it is weaker at tanning, not cleaner on the pigment side. My honest take after trying both: a low dose of MT-2 gets you further than MT-1 does, with the same mole trade per unit of tan.

What the research shows

The clinical program is old and small, but it is real, and the mechanism is confirmed in people:

In three healthy men given escalating subcutaneous doses from 0.01 to 0.025-0.03 mg/kg, two had increased pigmentation of the face, upper body, and buttocks one week after dosing ended.Life Sci 1996 · phase 1 · n=3

In 20 men with erectile dysfunction, increased sexual desire followed 13 of 19 MT-2 doses versus 4 of 21 placebo doses, p<0.01.IJIR 2000 · double-blind crossover · n=20

A 39-year-old man injected 6 mg of confirmed MT-2 and ended up in intensive care: heart rate hit 146 bpm, creatine phosphokinase rose to 17,773 IU/L. Three days to stabilize. That is what a reckless dose looks like.Clin Tox 2012 · confirmed exposure case

Realistic protocols

Forget the loading protocol. The old advice, 500 mcg a day for a week or two to “load,” was built for a time when supply was scarce and people wanted results fast. It also front-loads the nausea and the moles. Start at a normal dose, let the tan build with some UV, and then hold at the lowest amount that keeps it.

You need UV for MT-2 to work. The peptide primes your melanocytes, but melanin production still needs a light trigger. Some natural sun or a few minutes in a low-pressure bed around each dose is enough. You do not need to bake.

The libido effect arrives on its own. If you are running MT-2 for the tan, the MC4R activation comes included, and most people are happy to keep it.

Weeks 1–4250 mcg 2–3x/wkSub-q. Get some UV within a day of each dose to activate the tan.

Maintenance100–250 mcg 1–2x/wkOnce your base tan is set, drop to the minimum that holds it.

Side effects

Nausea up front, moles over time, and a pigment system you need to watch:

commonNausea after injection, worst in the first sessions and at higher doses. An antihistamine 30 minutes before helps most people get through it.

anecdotalFacial flushing and warmth right after the shot, usually gone in 20 minutes.

monitorNew moles and darkening freckles. This is the real cost, and it scales with cumulative dose. Get a baseline skin check and flag anything that changes shape or color.

commonSpontaneous erections and increased libido, dose-dependent. Welcome for most, inconvenient for some.

monitorMelanoma case reports exist in the literature, including an oral mucosal melanoma in a nasal-spray user. No proven causal link, but a peptide that drives melanocyte activity paired with aggressive UV is not a combination to dismiss.