# Melanotan 2 Dosage in Research: Doses Studied, Routes, and Half-Life > Melanotan 2 dosage as reported in the research literature: the Phase I doses studied, routes including injections, the half-life question, and stability — research context only, no human dosing. The doses, routes, and pharmacokinetics described in the published studies — reported as research facts, with no human dosing recommendation. ## Read this first This page describes **Melanotan 2 dosage** strictly as it appears in published research — what was given to which subjects, at what amount, by which route, in specific studies. It is **not** a dosing guide. No human dose is recommended here, because Melanotan 2 is not approved for human use and there is no safe, established dose for it. The numbers below come from small Phase I human studies and from rodent experiments. They are reported the way a literature review reports them: as facts of a study's design. Where a figure is a per-kilogram amount or a brain-microinjection amount, it tells you how an experiment was run — not what anyone should take. Pharmacokinetics — how fast the body clears the peptide, the **melanotan 2 half life** question — are covered below, and they are genuinely unsettled for this compound. ## Doses reported in the research literature In the **human pilot Phase I pigmentation study**, subcutaneous Melanotan 2 was escalated from 0.01 to 0.025-0.03 mg/kg and dosed every other weekday for two weeks; 0.025 mg/kg/day was the amount the authors recommended for subsequent Phase I work, and dose-limiting somnolence appeared at 0.03 mg/kg [2]. In the **controlled erectile-dysfunction crossover study**, the dose was 0.025 mg/kg subcutaneously [3]. The preclinical doses are not comparable to human use and are included only to characterize the research. In the mouse appetite study, Melanotan 2 was microinjected directly into a brain region (the nucleus accumbens) at 0.1-1 nmol per side — an intracerebral research technique, not a route any person uses [37]. In the female-rat sexual-behavior study, the dose was 1-3 mg/kg intravenously [39]. These cross routes and species and cannot be converted into a human figure. Again: these are study-design facts, not recommendations. ## Melanotan 2 half life and pharmacokinetics **No validated human pharmacokinetic half-life has been published for Melanotan 2 itself.** This is an important and often-misstated point. The half-life figures that circulate are extrapolated — from rodent data and from the related linear analog Melanotan 1. A rat intravenous study showed biphasic, rapid multi-compartment plasma clearance for Melanotan 2 [37]. For the related Melanotan 1 in humans, subcutaneous dosing gave an absorption half-life of roughly 0.07-0.79 hours and a terminal-phase half-life of roughly 0.8-1.7 hours [4]. A practical consequence holds across both compounds and is frequently misunderstood: **pigmentation persists for weeks after the peptide has cleared the blood**, because melanin synthesis continues downstream long after the signaling molecule is gone [4]. A short plasma half-life therefore does not mean a short-lived effect. ## Melanotan 2 injections and other routes studied Subcutaneous **injection** is the primary route used in both the human research and in self-administration; the controlled human studies used the subcutaneous route exclusively [2][3]. The injectable route is also where much of the documented harm originates — not only the compound's effects but the risks of unregulated, potentially non-sterile product and of needle sharing, which regulators have specifically flagged [29]. Other routes appear in the literature: intravenous and intracerebral microinjection in rodent studies [37][39], an intranasal spray documented in self-administration case reports (and unlicensed), and oral dosing, which is impractical because bioavailability is very low. None of these is an approved route, because Melanotan 2 has no approved use [32]. The deeper point for any reader: route does not rescue an unapproved, unregulated compound from the harms documented on [the effects page](/effects). ## Stability and handling, as reported The research literature describes Melanotan 2 as a lyophilized (freeze-dried) powder that is stable when kept cold and dry [1]. Its lactam-bridged cyclic structure gives it greater resistance to enzymatic breakdown than linear alpha-MSH, which is part of why it is more potent and longer-acting at the receptor than the natural hormone [1]. Preformulation work reported its acid-base properties (pKa values of 6.54 for histidine and 11.72 for arginine) and a log partition coefficient of 2.82 [1]. These are physicochemical facts from the characterization literature, included to round out the research picture. They describe how the molecule behaves in a laboratory, not a protocol for use — and they do not bear on the central reality that the compound is unapproved and its long-term human safety is unknown [32]. --- A direct reading of the Melanotan 2 photoprotection literature — the eumelanin science and the documented harms set out side by side and cited, with no clinic, no product, and no dose behind the name.