Thymosin Alpha-1 Dosage in the Research Literature

Before the details

This page reports Thymosin Alpha-1 doses exactly as they appear in published studies — what was given, to whom, and how. Nothing here is a recommendation, an instruction, or a protocol to follow. The peptide is given as a shot under the skin (subcutaneous, often shortened to SC) in essentially every clinical trial. Doses are measured in milligrams (mg). Across the literature, single doses studied have ranged from about 0.8 to 6.4 mg, and the long-used hepatitis regimen is 1.6 mg twice a week. It clears the blood fairly quickly — roughly a 2-hour half-life (the time for blood levels to fall by half). Because it is not approved in the US, there is no official label dose here; everything below is third-person research data, and any decision about a real human belongs with a qualified clinician, not a website.

Thymosin alpha 1 dosage: the ranges studied

A comprehensive review of four decades of clinical literature reports the standard single subcutaneous dose ranging from 0.8 to 6.4 mg, with multiple-dose regimens of 1.6 to 16 mg over five to seven days ^[4]. The most established regimen — the long-standing chronic hepatitis B and C protocol — is 1.6 mg subcutaneously twice weekly ^[4].

Trial protocols by setting, reported as research data:

• Sepsis (ETASS, TESTS): 1.6 mg subcutaneous every 12 hours for five to seven days ^[2][3].
• COVID-19 cohorts: 1.6 mg subcutaneous daily ^[6].
• Cancer-adjuvant protocols: 1.6 mg subcutaneous twice weekly in combination regimens ^[7].

These figures describe what investigators administered to defined patient populations under medical supervision. They are not a guide for personal use.

Doses studied by population — read as a record, not a menu

The clearest way to understand Thymosin Alpha-1 dosing is to see that it tracks the diagnosis, not the person. Across the published record, the same peptide was given at different frequencies for different conditions, always under medical supervision:

• Chronic hepatitis B/C: 1.6 mg subcutaneous twice weekly — the long-standing, most-established regimen ^[4].
• Severe sepsis (ETASS): 1.6 mg subcutaneous every 12 hours for five days, then once daily for two days ^[2].
• Sepsis (phase-3 TESTS): 1.6 mg subcutaneous every 12 hours for seven days ^[3].
• Severe COVID-19 cohorts: 1.6 mg subcutaneous daily ^[6].
• Cancer-adjuvant combination protocols: 1.6 mg subcutaneous twice weekly ^[7].

Notice the recurring 1.6 mg unit dose and the way only the frequency and duration change. That pattern is a feature of how the drug was studied in regulated settings abroad; it is descriptive history, not a template for anyone to copy. The single biggest caveat belongs right here: the every-12-hour sepsis regimen above is exactly the protocol that, at full phase-3 scale, produced no mortality benefit ^[3].

Thymosin alpha 1 injection: route, half-life and handling

Subcutaneous injection is the primary clinical route in essentially every trial; mechanistic work also used in-vitro and mouse models ^[4]. After a subcutaneous dose in human volunteers, the peptide reaches peak levels in roughly one to two hours and has an elimination half-life of about two hours, with blood levels returning toward baseline within about 24 hours; its distribution is consistent with extracellular fluid. That short half-life is part of why the studied regimens dose repeatedly — twice weekly for chronic settings, every 12 hours for acute ones — rather than once and done.

It is a highly acidic peptide (isoelectric point around 4.2) that does not extensively bind plasma proteins and is broken down by tissue and circulating aminopeptidases ^[4]. It is supplied lyophilized (freeze-dried), and its N-terminal acetyl group is required for activity ^[1]. The freeze-dried form is part of why community users report uncertainty about reconstitution and sterile handling — a usability issue, not a property that changes the molecule's biology. Because research-grade material sits outside any regulated drug-quality chain, the actual content and identity of a given vial are not guaranteed, which compounds the problem of reasoning about dose from an unverified product ^[4].

Why no human dose is given here

Thymosin Alpha-1 (thymalfasin) is approved abroad but not in the United States, and the doses above come from supervised clinical and trial settings tied to specific diagnoses. Extrapolating approved-abroad clinical dosing to unregulated or self-administered use is not supported by the evidence and falls outside any approved indication. This digest therefore reports doses only as 'studied at X mg in [population] by [route].' For the human-experience layer and the cited cautions, see the Thymosin Alpha-1 effects page.