Melanotan 2 dosage: what was administered in the research

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This page describes the Melanotan 2 dosage amounts used in published experiments. It is not a guide, a protocol, or a recommendation, and it never tells anyone how much to use. Melanotan 2 is not approved as a medicine in any country, so there is no official approved dose and no medically established safe amount in humans.

Most dosing data come from animals, where researchers gave precise amounts by weight (for example, micrograms per kilogram) or injected tiny amounts straight into the brain to study specific circuits. The few human numbers come from two small, decades-old studies. Where a dose appears below, it is a fact about a specific experiment in a specific species — read it that way, not as something to copy.

Doses used in the human studies

Only two small human studies report doses. In the Phase I tanning pilot, three healthy men received escalating subcutaneous doses from 0.01 up to 0.025–0.03 mg/kg, given every other weekday over two weeks; pigmentation appeared after just five low doses, and 0.025 mg/kg/day was the dose recommended for any future Phase I work ^[1]. The same study saw dose-limiting drowsiness at 0.03 mg/kg.

In the erectile-dysfunction crossover study, 10 men each received a single 0.025 mg/kg subcutaneous dose, which produced clinically apparent erections in 8 of them ^[2]. Nausea was dose-related and was reported as severe in roughly 13% of subjects at 0.025 mg/kg across the controlled studies. These are the only controlled human dose figures that exist, and both studies are from the 1990s with fewer than 20 people combined.

Doses used in the animal research

The animal literature uses a much wider range, matched to each study's question. For appetite research, mice received 0.1, 0.3, or 1 nanomole per side injected directly into the nucleus accumbens — vanishingly small amounts placed precisely in a brain reward region ^[5]. For sexual-behavior work, female rats received 1 and 3 mg/kg intravenously ^[37]. Metabolic and thermogenesis studies used central (into-the-brain) infusions in rats and mice at low and high doses ^[8][10][11].

These routes — direct brain injection and intravenous infusion — are laboratory techniques used to isolate where and how the peptide acts. They are not the routes people use, and the doses are not translatable to a person.

Melanotan 2 injections and routes studied

When people discuss melanotan 2 injections, they almost always mean subcutaneous injection — under the skin — which is the primary route in both the human studies and in self-administration ^[1][2]. The research literature also documents intravenous dosing (used in rodent pharmacokinetic and behavioral studies), and direct brain administration (intracerebroventricular and intracerebral microinjection) used to study appetite, energy, and thermogenesis ^[5][8].

Two other routes appear in the record. Intranasal sprays are documented in self-administration case reports but are unlicensed. The oral route is impractical: bioavailability is very low (around 4.6% in rats), so swallowing it does not work ^[3]. None of this is instruction — it is a description of how the compound has been delivered in studies and in undocumented self-use.

Melanotan 2 half life

The melanotan 2 half life is genuinely uncertain because no validated human pharmacokinetic study of Melanotan 2 itself has ever been published. The closest data are a rat intravenous study, which showed rapid, biphasic, multi-compartment clearance from plasma ^[36], and human data on the related linear analog, which had 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 ^[35].

The practical point is that the peptide leaves the blood quickly — within hours — but its effects outlast it. Pigmentation in particular persists for weeks after the peptide has cleared, because melanin synthesis continues downstream long after the drug is gone ^[35]. Any 'half-life' figure you see quoted for Melanotan 2 is extrapolated from rodent data or from the linear analog, not measured directly in humans.

Stability and handling in the literature

Published preformulation work describes Melanotan 2 as a freeze-dried (lyophilized) powder that is stable when kept cold and dry, with reconstituted solutions typically refrigerated at about 4°C per general peptide-laboratory practice. Its ring-closed (lactam-bridged) structure makes it more resistant to enzymatic breakdown than the natural linear alpha-MSH, which is part of why it is so much more potent. Reported physical constants include pKa values of 6.54 (histidine) and 11.72 (arginine) and an octanol/water log partition coefficient of about 2.82. These are laboratory storage and chemistry facts, not preparation instructions.