Melanotan 2 Dosage: What the Studies Used

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This page reports the Melanotan 2 doses that appear in published studies. It is not a how-to and not a recommendation. Melanotan 2 is not approved for human use anywhere, so there is no medically endorsed dose, and nothing here should be read as one. Researchers report doses in milligrams (mg) or micrograms (ug) per kilogram of body weight, and by route — usually subcutaneous (a shallow injection under the skin) in humans, and various routes in animals.

A quick note on the numbers below: the human figures come from two small Phase I studies, and the rest come from rodents, where doses don't translate to humans at all. We include them so the literature is transparent, with each tied to its study. We do not describe how to mix, measure, or inject anything, and we never say "you should."

Doses reported in human studies — melanotan 2 injections

All human Melanotan 2 dosing on record comes from small Phase I work, given by subcutaneous injection.

• Pigmentation pilot (Dorr et al., 1996): three healthy men, escalated from 0.01 to 0.025-0.03 mg/kg per day, dosed every other weekday for two weeks. The 0.025 mg/kg/day level was the one suggested for future Phase I work; 0.03 mg/kg caused dose-limiting drowsiness ^[4].
• Erectile-dysfunction crossover (Wessells et al., 1998): 10 men, a single 0.025 mg/kg subcutaneous dose versus placebo ^[5].

That's the entire controlled human dosing record. No Phase II or Phase III trial has ever been completed for Melanotan 2, so doses beyond these small studies are undocumented in any trial setting ^[3].

Doses reported in animal studies

Animal doses span a wide range and different routes, because researchers were probing different systems:

• Appetite (mice): 0.1-1 nmol microinjected directly into the nucleus accumbens, a brain reward region ^[6].
• Pharmacokinetics (rats): intravenous dosing in a method-comparison study that tracked how fast the peptide cleared the blood ^[48].

These routes (into the brain, into a vein) and tiny molar amounts have no relationship to how the compound is used outside the lab, and cannot be converted to a human dose.

Half-life and clearance — melanotan 2 half life

There is no validated human pharmacokinetic half-life published for Melanotan 2 itself. A rat intravenous study showed rapid, biphasic, multi-compartment plasma clearance — meaning the peptide leaves the bloodstream quickly and in more than one phase ^[48]. The closely related linear analog afamelanotide (Melanotan I) in humans showed a beta-phase half-life of roughly 0.8-1.7 hours after subcutaneous dosing, used here only as a family comparison ^[49].

Here's the catch that confuses people: the tan long outlasts the peptide. Because melanin synthesis continues downstream after the molecule is gone, pigmentation persists for weeks even though the compound itself clears in hours. So "how long it stays in you" and "how long you stay dark" are two very different questions. Any half-life figure you see attached to Melanotan 2 is extrapolated from rodent data or from the related Melanotan I, not measured in humans on Melanotan 2.

Routes and stability reported in the literature

Studies and case reports document several routes: subcutaneous injection (the primary research and self-administration route), intravenous (rodent studies), intracerebral microinjection (rodent appetite/energy work), intranasal spray (in unlicensed self-administration case reports), and oral — which is impractical given the roughly 4.6% oral bioavailability measured in rats ^[43].

On handling, the literature describes Melanotan 2 as a lyophilized (freeze-dried) powder, with the lactam-bridged cyclic structure giving it more enzyme resistance than linear alpha-MSH; preformulation data report pKa values of 6.54 and 11.72 and an octanol/water log partition coefficient of 2.82 ^[43]. These are physicochemical facts from characterization studies, not preparation instructions.