Research review / Doses studied
Melanotan 2 in the Dose Literature: What Was Administered, to What
The doses, routes, and pharmacokinetics recorded in the published studies — strictly as study-design facts, never as guidance. Melanotan 2 is not approved for human use.
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This page reports what researchers gave, to whom, and by what route — as recorded in published studies. It is not a guide, a protocol, or a recommendation, and it contains no instructions. Melanotan 2 is approved nowhere for human use, so there is no labeled dose to cite. Where a number appears, it is a study-design fact about a specific experiment.
A recurring search is the melanotan 2 half life. The honest answer is that no validated human half-life has been published for Melanotan 2 itself. The numbers people pass around are extrapolated from rodent data and from the related linear analog. The one thing the literature is clear on: the tan persists for weeks regardless, because pigment synthesis continues long after the peptide has cleared the blood. So 'how long it lasts' splits into two different questions — how long the molecule lingers, and how long the color does — with very different answers.
Doses recorded in the studies
In the human pilot Phase I study, subcutaneous Melanotan 2 was escalated from 0.01 to 0.025-0.03 mg/kg/day across a five-dose escalation, with 0.025 mg/kg/day recommended for subsequent Phase I work [1]. The controlled human erectile-dysfunction studies used 0.025 mg/kg subcutaneously [2]. These are the only human figures, and they come from small studies that were never followed by later-phase trials — a study-design fact, not a dose to follow.
The rodent figures are not convertible to human use and are reported only for completeness. Appetite microinjection studies used 0.1-1 nmol delivered directly into the nucleus accumbens of mice [5]. Across the broader rodent literature, doses were chosen per experiment to probe receptor pharmacology, not to model a human regimen [10][13]. Route matters as much as amount: the same molecule behaves differently injected under the skin, given intravenously, or microinjected into the brain.
Routes studied and the melanotan 2 half life question
Routes documented in the literature include subcutaneous injection (the primary research and self-administration route), intravenous (rodent pharmacokinetic and behavioral studies), and intracerebroventricular or intracerebral microinjection (rodent appetite, energy, and thermogenesis work) [1][2][5]. Self-administration case reports also document unlicensed intranasal sprays; oral bioavailability is low (around 4.6% in rats) and not a practical route.
On the melanotan 2 half life: no validated human pharmacokinetic half-life exists for Melanotan 2. A rat intravenous study showed biphasic, rapid multi-compartment plasma clearance, and the closely related linear analog Melanotan 1 (afamelanotide) 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 [3]. For both compounds, pigmentation persists for weeks after the peptide has cleared because melanin synthesis continues downstream [9]. The cyclic lactam structure confers greater enzymatic resistance than linear alpha-MSH, which is part of why the molecule was engineered as a ring in the first place [3].
Why no human guidance follows
The dose literature cannot be turned into guidance for three reasons. First, the human data is tiny — fewer than two dozen subjects across two small studies — and was never validated in the larger trials that establish a safe range [1][2]. Second, online product is unregulated: forensic analyses repeatedly find inaccurate labeling and variable content, so even a number from a study cannot be reliably reproduced from a purchased vial [30][31]. Third, the dose-related adverse effects are real: nausea was dose-related and was severe in roughly 13% of subjects at 0.025 mg/kg in controlled studies, and the serious case reports include events after apparent overdose [2][18].
The responsible reading is that the published doses describe experiments, not practice. For the documented effects and harms that accompany use, see Melanotan 2 effects; for the full study record, see the Melanotan 2 research page.