# Melanotan 2 Dosage in the Research: Doses Studied, Routes, and Half-Life > Melanotan 2 dosage as documented in the research literature: the doses studied by route and species, the half-life data, and stability notes. Not a dosing guide. What was administered, to which species, by which route — and the half-life data. A reading of the literature, not a protocol. ## Read this first This page describes the doses of Melanotan 2 that appear in published studies. It is not a dosing guide, it makes no recommendation, and it gives no instructions for use. Melanotan 2 is not approved for human use anywhere, and the only controlled human studies ever done used three and ten subjects. Doses here are facts of those experiments — 'a Phase I study administered X mg/kg subcutaneously' — and nothing more. Reading them tells you what researchers gave laboratory animals and a handful of volunteers; it does not tell you what is safe, and the unregulated product sold online has no verified dose at all. Where numbers are precise, they are precise because the study reported them. Where the human pharmacokinetics are unknown, the page says so plainly. ## Doses recorded in the studies In the human pilot Phase I dose escalation, subcutaneous Melanotan 2 ran from 0.01 to 0.03 mg/kg/day, dosed every other weekday, with 0.025 mg/kg/day recommended for later Phase I work [1]. The controlled human erectile-dysfunction study used 0.025 mg/kg subcutaneously [2]. In rodent appetite work, 0.1-1 nmol was microinjected directly into the nucleus accumbens [5]. In the diet-induced obesity study, the agonist was delivered centrally to rats [6]. These are not comparable to one another — a microgram-per-kilogram subcutaneous human dose and a nanomole intracerebral rodent dose live in different worlds — and none translates to a use recommendation. ## Melanotan 2 half life No validated human pharmacokinetic half-life has been published for Melanotan 2 itself. A rat intravenous study showed biphasic, rapid, multi-compartment plasma clearance [32] — the peptide leaves the blood quickly. By contrast, pigmentation persists for weeks after the peptide has cleared, because melanin synthesis continues downstream long after the signal is gone. Half-life figures circulated online are extrapolations from rodent data and from the related linear analog, not measured human values for Melanotan 2. The honest statement is the precise one: human pharmacokinetics for Melanotan 2 have not been characterized [1]. ## Melanotan 2 injections: routes studied Subcutaneous injection is the primary research and self-administration route, reflecting the peptide's poor oral bioavailability of about 4.6% in the rat [7]. Intravenous dosing appears in rodent pharmacokinetic and behavioral work [32]. Intracerebroventricular and intracerebral microinjection were used in rodent appetite, energy, and behavior studies [5]. Intranasal sprays are documented in self-administration case reports but are unlicensed and uncharacterized. The lactam-bridged ring confers greater enzymatic resistance than linear alpha-MSH, which is part of why the molecule survives injection at all [7]. Describing these routes is not endorsing them — the safety record on the [Melanotan 2 effects](/effects) page applies to every route. ## Stability, as the literature notes it Melanotan 2 is reported as a lyophilized (freeze-dried) powder that is stable kept cold and dry, with reconstituted solutions typically refrigerated at about 4 degrees Celsius per general peptide-laboratory practice. Preformulation data report dissociation constants of pKa1 6.54 (histidine) and pKa2 11.72 (arginine) and an octanol/water log partition coefficient of 2.82 [7]. These are bench characterizations of the molecule, recorded for completeness — not handling instructions for any reader. --- A cinematic reading of one peptide's published record — its light and its shadow, cited; not a clinic, not a vendor, not a prescription.