Melanotan 2 Dosage in the Research: Doses Studied, Routes, and Half-Life
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This page reports the doses of Melanotan 2 that researchers gave in published studies, to specific people or animals, for specific experiments. That is all it is — a record of what was studied. It is not a protocol, not a recommendation, and not instructions, and Melanotan 2 is not approved for human use anywhere.
In plain terms: the small human studies used very low amounts measured against body weight, given as injections under the skin. Most of the detailed dose work is in rats and mice. There is no proper human half-life number — how long the drug stays in the body has only been measured in animals, and the tan itself outlasts the drug because the pigment, once made, takes weeks to fade. Wherever a number appears below, read it as 'this is what a study used,' not 'this is what to take.'
Doses used in the human studies
The human pilot Phase I dose escalation used subcutaneous Melanotan 2 from 0.01 to 0.03 mg/kg/day, dosed every other weekday, with 0.025 mg/kg/day recommended for subsequent Phase I work [1]. The controlled erectile-dysfunction studies used a single subcutaneous dose of 0.025 mg/kg [2]. These are the only controlled human dose figures that exist, drawn from studies of three to twenty subjects, and they are reported here strictly as study-design facts. No Phase II or Phase III trial has ever set a therapeutic dose, because none has been completed.
Doses used in animal research
The rodent literature explored a wider range. Appetite studies microinjected 0.1-1 nmol per side directly into the nucleus accumbens of mice [35]. A rat peripheral-nerve-regeneration study found 20 ug/kg subcutaneously every 48 hours effective while 2 and 50 ug/kg were not — a bell-shaped dose-response in which more was not better. Female-rat sexual-behavior work used 1-3 mg/kg intravenously. These doses were chosen for laboratory questions in animals and have no human equivalent; they are recorded only to show the research context.
Melanotan 2 half life: what is and is not known
There is a real gap here, and it is worth stating plainly. No validated human pharmacokinetic half-life has been published for Melanotan 2 half life itself. A rat intravenous study showed biphasic, rapid multi-compartment plasma clearance. The closely related linear analog Melanotan I (afamelanotide), measured in humans, had an absorption half-life of roughly 0.07-0.79 hours and a terminal half-life of roughly 0.8-1.7 hours after subcutaneous dosing. Any half-life figure circulating for Melanotan 2 is therefore extrapolated from rodent data or from the related analog, not measured in humans. Critically, pigmentation persists for weeks after the peptide has cleared, because melanin synthesis continues downstream long after the signal is gone.
Melanotan 2 injections and routes studied
Melanotan 2 injections under the skin are the primary route in both research and unsupervised use. Other routes appear in the literature: intravenous in rodent pharmacokinetic and behavioral studies, intracerebral and intracerebroventricular microinjection in rodent appetite and energy work, and intranasal spray documented in self-administration case reports (unlicensed). Oral dosing is impractical — bioavailability was only about 4.6% in rats. This site does not describe how to reconstitute or inject the compound; that is outside its editorial remit, and the unregulated-product and contamination problems documented elsewhere on the melanotan 2 side effects page apply to any injected material of unknown origin.
Stability as reported
The compound is described as a lyophilized (freeze-dried) powder that is stable kept cold and dry; reconstituted solutions are typically refrigerated near 4 C per general peptide-laboratory practice. The lactam-bridged cyclic structure gives it greater enzymatic resistance than linear alpha-MSH. Preformulation work reported pKa values of 6.54 (histidine) and 11.72 (arginine) and an octanol/water log partition coefficient of 2.82 [34]. These are physical-chemistry facts about handling the substance in a laboratory, not guidance for use.