# Melanotan 2 Dosage Research, Injections & Half-Life | Melanotan 2

> Melanotan 2 dosage in the research context: the doses, routes (including injections), and half-life reported in studies of Melanotan II — study facts only, never a dosing recommendation.

What was administered, to which species, by which route — reported as research facts, not as guidance for anyone to follow.

## The short version

This page reports the doses, routes, and timing used in Melanotan 2 studies. It is not a how-to. Melanotan 2 is not approved for human use anywhere, there is no established human dose, and nothing here should be read as a recommendation to use it.

With that said, the research record is specific. The few human studies used very small subcutaneous (under-the-skin) injections, scaled to body weight. Rodent studies used a wider range and several routes, including injections straight into the brain to study appetite. One striking finding is that more is not better: a rat nerve study found a middle dose worked while both lower and higher doses did nothing. No one has ever published a reliable measurement of how long Melanotan 2 stays in the human body. What we have is rat data and figures borrowed from its close cousin. Every number below comes from a named study.

## Doses used in the human studies

Human exposure to Melanotan 2 has only ever been studied at small scale. The 1996 pilot Phase I study escalated subcutaneous doses from 0.01 to 0.025–0.03 mg/kg, dosed every other weekday for two weeks, and recommended 0.025 mg/kg/day for future Phase I work [2]. The controlled erectile-dysfunction study used a single subcutaneous dose of 0.025 mg/kg [3].

These are reported strictly as the doses investigators administered in supervised research — they are study-design facts, not dosing recommendations, and Melanotan 2 is not approved for human use [4]. No larger trial has ever established a human dose [4].

## Melanotan 2 injections and other routes studied

Subcutaneous injection is the primary route in both research and unsanctioned self-administration [2]. Rodent pharmacology has used additional routes that do not translate to people: intravenous dosing in pharmacokinetic and behavioral studies, and intracerebroventricular or direct intracerebral microinjection to probe appetite and energy circuits — for example, 0.1–1 nmol microinjected into the nucleus accumbens in mouse appetite studies [39].

Dose-response is not always linear. In a rat peripheral-nerve-regeneration study, 20 µg/kg every 48 hours was effective while 2 and 50 µg/kg were not — a bell-shaped curve in which the middle dose worked and the extremes did not. Oral dosing is impractical: bioavailability is very low, so the peptide is not meaningfully absorbed by mouth. Unlicensed nasal sprays appear in self-administration case reports but are not a validated route [11].

## Melanotan 2 half-life and stability

There is a persistent question about Melanotan 2 half life, and the honest answer is that no validated human pharmacokinetic half-life has been published for Melanotan 2 itself. A rat intravenous study showed biphasic, rapid multi-compartment plasma clearance, but that is rodent data.

The most-cited figures actually come from the closely related linear analog, Melanotan I (afamelanotide), measured in humans: complete subcutaneous bioavailability relative to intravenous, an absorption-phase 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, with no detectable levels after oral dosing [14]. In both compounds, the visible effect outlasts the molecule by weeks: pigmentation persists long after the peptide has cleared because melanin synthesis continues downstream [14]. As a lyophilized (freeze-dried) powder, Melanotan 2 is reported as stable when kept cold and dry, with reconstituted solutions typically refrigerated per general peptide-laboratory practice; the cyclic lactam-bridged structure gives it more enzymatic resistance than linear alpha-MSH [1].

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A comparative reading of the Melanotan 2 record set beside its melanocortin cousins — the approved photoprotection and sexual-function analogs cited where their trials hold, the parent peptide's tiny old human data and documented mole, kidney, and priapism harms kept in plain view, and the community reports pinned to one side as anecdote; no clinic behind the name and nothing here dosed, sourced, prescribed, or sold.