Doses studied
Thymosin Alpha-1 Dosage, As Studied — Not As Advised
What was administered, to whom, by which route, and how the body clears it. No recommendations.
Read this first
This page describes Thymosin Alpha-1 dosage only as it appears in published studies and in countries where the drug (thymalfasin) is approved. It is not a recommendation, and it contains no instructions to follow. In approved hepatitis use, the common regimen is a small subcutaneous (under-the-skin) injection of 1.6 mg twice a week. Sepsis and COVID-19 trials used more frequent schedules over a week or so. The peptide clears the body quickly — its half-life (the time for blood levels to halve) is about two hours — which is why standard regimens repeat it. Everything below is third person and study-attributed: "studied at X mg in Y population by Z route," never "take X." For who has a reason to be cautious, see the effects page.
Thymosin alpha 1 dosage: the ranges studied
Across four decades of literature, Thymosin Alpha-1 dosage clusters around a small subcutaneous dose. A comprehensive review reports single subcutaneous doses studied across a 0.8–6.4 mg range, with multiple-dose regimens of 1.6–16 mg given over five to seven days [4]. The long-standing chronic-hepatitis regimen is 1.6 mg subcutaneously twice weekly. In the ETASS and TESTS sepsis trials, the protocol was 1.6 mg every 12 hours for five to seven days [2][3]. COVID-19 cohort studies used 1.6 mg subcutaneously daily [6]. These are reported trial protocols in defined patient populations — not doses for general use.
Thymosin alpha 1 injection: route and handling
In essentially every clinical trial, the Thymosin alpha 1 injection route is subcutaneous — a small injection into the fat layer under the skin. The peptide is highly acidic (isoelectric point around 4.2), does not bind plasma proteins extensively, and is degraded by tissue and circulating aminopeptidases; it is supplied lyophilized (freeze-dried) and reconstituted before use, and its N-terminal acetyl cap is required for activity [4]. Because the molecule is cleared quickly, the studied regimens rely on repeat dosing rather than a single administration. The most common reported issue with the injection itself is a mild local reaction at the site [15].
Half-life and clearance
Human pharmacokinetic work puts the elimination half-life at roughly two hours after subcutaneous injection, with peak blood levels reached within about one to two hours and a return toward baseline within roughly 24 hours; the volume of distribution is consistent with the peptide spreading through extracellular fluid [4]. This short half-life is the practical driver behind the twice-weekly chronic regimen and the once- or twice-daily acute-care schedules — and it is exactly why recent formulation research is pursuing long-acting depots that could stretch release out to two weeks [17].
Why none of this is a protocol
The doses above come from approved-abroad clinical settings and controlled trials in specific patient groups. Extrapolating them to unregulated or self-administered use is not supported by the evidence and falls outside any approved indication. The most rigorous outcome trial in sepsis was null [3], so even within studied settings a dose is not a guarantee of benefit. This page documents what researchers administered; it does not tell anyone what to do.