Melanotan 2 dosage: what studies used, nothing more.

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This page lists doses that appear in published Melanotan 2 studies. Every figure is a study-design fact — what researchers gave to which species, by which route. None of it is a recommendation, a protocol, or a how-to. Melanotan 2 is not approved for human use anywhere ^[4], and this site gives no human dosing.

In plain terms: a few small human pilots used roughly hundredths of a milligram per kilogram of body weight, injected under the skin. Rodent studies used micrograms per kilogram, or tiny amounts injected straight into the brain to study the brain effects. There is no validated human half-life (how long it stays active) for Melanotan 2 itself — that number is borrowed from rat data and from a related compound. The terms below are glossed as they appear.

Doses used in the studies

Research-context only — not a dosing guide.

• Human pilot (pigmentation), Dorr 1996: subcutaneous Melanotan II escalated from 0.01 to 0.025-0.03 mg/kg/day, dosed every other weekday for two weeks. 0.025 mg/kg/day was the dose suggested for further Phase I work ^[1]. Somnolence was dose-limiting at 0.03 mg/kg.
• Human erectile-dysfunction studies, Wessells 1998: a single 0.025 mg/kg subcutaneous dose in men with psychogenic ED ^[2].
• Rat nerve regeneration, Ter Laak 2003: 20 ug/kg subcutaneous every 48 hours was effective; 2 and 50 ug/kg were not — a bell-shaped dose-response where more is not better ^[7].
• Mouse appetite (brain), Eliason 2022: 0.1-1 nmol microinjected directly into the nucleus accumbens ^[5].

The pattern across the controlled human work: low subcutaneous doses produced measurable effects, with nausea that was dose-related and severe in roughly 13% of subjects at 0.025 mg/kg ^[2].

Melanotan 2 half life

There is no validated human pharmacokinetic half-life published for Melanotan 2 itself. A rat intravenous study showed biphasic, rapid multi-compartment plasma clearance. The closely related linear analog Melanotan I (afamelanotide) in humans showed 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.

The key point for the melanotan 2 half life question: the peptide clears fast, but the visible effect does not. Pigmentation persists for weeks after the compound is gone, because melanin synthesis continues downstream once the receptors have been switched on. A 2026 case report tracked this directly — oral pigment from self-administration was still partly present at 3 months after stopping ^[31].

Routes and melanotan 2 injections

Routes documented in the literature, listed as study facts:

• Subcutaneous injection — the primary research and self-administration route. When people search melanotan 2 injections, this is the route the studies and case reports describe. The peptide is not orally practical: rat bioavailability by mouth is roughly 4.6%.
• Intravenous — used in rodent pharmacokinetic and behavioral studies ^[8].
• Intracerebroventricular and intracerebral microinjection — used in rodent appetite, energy, and thermogenesis research to isolate brain effects ^[5].
• Intranasal spray — documented in self-administration case reports; unlicensed and unstudied for safety ^[31].

Reported as a lyophilized (freeze-dried) powder, stable kept cold and dry; reconstituted solutions are typically refrigerated per general peptide-laboratory practice. The lactam bridge — an internal chemical link that closes the peptide into a ring — makes it more resistant to enzyme breakdown than linear alpha-MSH. None of this is reconstitution or injection instruction; it is a summary of how the published studies handled the compound.