What was studied
Melanotan 2 Dosage in the Research: Doses, Routes and Half-Life
What doses appeared in the studies, by which route, and what little is known about how long the peptide lasts — reported as research facts, never as guidance.
Read this first
This page explains what Melanotan 2 dosage looked like in the research — and only that. Every figure here is a study-design fact: the dose a researcher gave to a person or animal in a published experiment. None of it is a recommendation, a protocol, or a how-to, and Melanotan 2 is not approved for human use anywhere.
The short version: the small human studies used very low subcutaneous (under-the-skin) doses, around 0.025 mg/kg, given every other day. Animal studies used a wide range by various routes. No reliable human half-life has ever been published, so claims about 'how long it lasts' are extrapolated, not measured. We lay out the numbers below so you can read the studies accurately — not so you can copy them.
Melanotan 2 injections: the routes studied
Across the literature, Melanotan 2 has been studied by several routes. Subcutaneous injection is the main one in both research and self-administration. Intravenous dosing appears in animal pharmacokinetic and behavior studies. Direct brain microinjection (into the ventricles or specific regions) is used in rodent appetite and energy research. Intranasal sprays are documented in self-administration case reports but are unlicensed. Oral dosing is impractical — bioavailability in rats was only about 4.6%.
So when people discuss melanotan 2 injections, they are describing the subcutaneous route the human pilot study used (Dorr 1996) [1]. We describe that as a research method, not an instruction; this site gives no reconstitution or injection how-to.
The doses that appeared in the human studies
Two small human studies anchor the human dose figures, both reported here strictly as research facts. The 1996 pilot Phase I pigmentation study escalated subcutaneous Melanotan 2 from 0.01 to 0.025-0.03 mg/kg, dosed every other weekday for two weeks, and the authors recommended 0.025 mg/kg/day for future Phase I work (Dorr 1996) [1]. The 1998 erectile-function crossover study used a single subcutaneous dose of 0.025 mg/kg (Wessells 1998) [32].
That 0.025 mg/kg figure is the most-cited human study dose. Notably, the studies recorded that nausea was dose-related and that the highest dose (0.03 mg/kg) caused dose-limiting daytime sleepiness [1]. These are observations from controlled experiments — described, not endorsed.
The doses that appeared in animal studies
Animal research used a much wider range, by route, because the questions were different. Appetite studies microinjected 0.1-1 nmol per side into the nucleus accumbens of mice (Eliason 2022) [37]. A rat nerve-regeneration study found 20 ug/kg every 48 hours effective, while 2 and 50 ug/kg were not — a bell-shaped dose-response where more is not better. Female-rat sexual-behavior work used 1-3 mg/kg intravenously.
The takeaway from the animal dosing is not a number to copy — it is that the dose-response is not simple, and that the effective window in one model does not translate to another, let alone to a person. This is exactly why the research framing matters and why we publish no human protocol.
Melanotan 2 half life: what is and isn't known
Here is an honest answer to a common question. No validated human pharmacokinetic half-life has ever been published for Melanotan 2 itself [3]. Anyone quoting a precise human half-life for it is extrapolating.
What does exist: a rat intravenous study showed rapid, multi-compartment plasma clearance. The closely related linear analog Melanotan I, measured in humans, had an absorption half-life of roughly 0.07-0.79 hours and a beta-phase half-life of roughly 0.8-1.7 hours after subcutaneous dosing [33]. So the peptide family clears within hours. Critically, the visible tan persists for weeks regardless, because melanin synthesis continues downstream long after the peptide is gone — the half-life of the drug and the duration of the effect are two very different things.
How much melanotan 2 to inject — why this site won't tell you
People search how much melanotan 2 to inject, so let us be direct about why you will not find a number-to-use here. Melanotan 2 is not approved for human use by the FDA or any other regulator, no human dosing has been established through completed trials, and the products sold online have repeatedly been found mislabeled, contaminated, or wrongly concentrated [5][6]. A 'dose' calculated from an unverified vial is meaningless.
On top of that, the documented harms — kidney injury, priapism, brain-swelling, and melanoma case reports — are real and serious [2][24][28][21]. The responsible thing a research digest can do is report the study doses as historical facts and point you to the full effects and safety record. That is editorial commentary on the science, not a green light to inject anything.