Thymosin Alpha-1

Immune Modulation

aka Tα1 · Thymalfasin · Zadaxin

Compare

Formula

MW (Da)

Half-life

~2 hours

Saves

Overview

Thymosin alpha-1 (thymalfasin / Zadaxin) is a synthetic 28-amino-acid peptide identical to the endogenous form. International monographs describe use in chronic hepatitis B and as an immunomodulator. It is NOT FDA-approved — the FDA's 2024 compounding briefing explicitly states no Tα1 drug products are approved in the U.S.

Mechanism

Reviews describe Thymosin Alpha-1 as an immunomodulator that enhances T-cell, dendritic-cell, and antibody responses, modulates cytokines and chemokines, and can block steroid-induced apoptosis in thymocytes. The clearest label-backed indication is chronic hepatitis B; broader literature discusses viral and oncologic adjunctive uses with regulatory acceptance varying by country.

0

Vendors

—

no vendors yet

Lowest price

—

Reported benefits

Chronic hepatitis B response advantage in pooled Zadaxin trials

The Zadaxin monograph summarizes pooled and individual trial response advantages versus placebo after 1.6 mg subcutaneous dosing twice weekly for 6 months in chronic hepatitis B.

[thymosin-zadaxin-monograph]

clinical

Broader immunomodulatory and adjunctive uses (varies by country)

Literature discusses viral and oncologic adjunctive uses, but regulatory acceptance varies by country and indication. NOT FDA-approved in the U.S.

[thymalfasin-pubchem]

clinical

Reported side effects

Drug-related adverse events under 1% in monograph dataset
clinical
The Zadaxin monograph describes Tα1 as well tolerated, with fewer than 1% drug-related adverse events across more than 2,000 individuals.
Mostly local injection-site discomfort; rare other effects
clinical
Reported effects are mainly local injection-site discomfort, with rare erythema, transient muscle atrophy, polyarthralgia with hand edema, and rash.

Dosing notes

Per monograph (chronic hepatitis B): 1.6 mg subcutaneously twice weekly, with doses separated by 3 or 4 days, for 6 months. In the U.S. these are NOT FDA-approved dosing standards because no Tα1 product is FDA-approved.

Research use only. Information on this page is editorial reference, not medical or dosing advice. Always consult qualified medical guidance before use.

Storage

Per Zadaxin monograph: store at 2–8 °C and use immediately after reconstitution.

Vendors carrying Thymosin Alpha-1

No approved vendors are listing this peptide yet. Check back later or browse the full vendor directory.

Discussion

Ask, answer, and vote on questions about Thymosin Alpha-1.

No questions yet. Be the first to ask.

References

[thymalfasin-pubchem]
Thymalfasin (Thymosin Alpha-1) compound entry
PubChem (NIH) · PubChem
Source
[thymosin-zadaxin-monograph]
Zadaxin (Thymosin Alpha-1) Indonesia BPOM assessment report and monograph
Indonesia BPOM · BPOM (Indonesia FDA equivalent) assessment
Source