Thymosin Alpha-1
Naturally occurring 28-amino-acid acetylated peptide (synthetic form)
Also known as Tα1, Thymalfasin, Zadaxin (proprietary name of a licensed product)
A thymic peptide studied for immunomodulatory activity. Its synthetic form, thymalfasin, is licensed in a number of countries (not the UK or US) as an adjunct in hepatitis B and other indications.
Technical information
Values are shown with their status. “Verified” means the value has been checked against a primary database such as PubChem.
- Classification
- Naturally occurring 28-amino-acid acetylated peptide (synthetic form)
- CAS number
- 62304-98-7 Pending
- Molecular formula
- C129H215N33O55 Pending
- Molecular weight
- 3108.3 g/mol Pending
- Sequence / structure
- Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN Pending
Some values are still being checked and should be treated as provisional until marked verified.
How this compound is tested
LC-MS identity (acetylated N-terminus) and HPLC purity; water content and counter-ion are relevant for net peptide content.
Research background
Thymosin α1 was isolated from thymosin fraction 5 in the 1970s and later found to be derived from prothymosin α. Thymalfasin (synthetic Tα1) is approved in more than 30 countries, mainly in Asia and Latin America, for chronic hepatitis B and as a vaccine adjuvant, but not by the UK MHRA, EMA or US FDA. Research interest concerns innate and adaptive immune modulation.
Mechanisms investigated in published research
These are the mechanisms examined in the cited literature. Describing them is not a claim that the compound produces any effect in humans.
- Toll-like receptor signalling (TLR2/TLR9) in dendritic cells, reported in cell and mouse studies.
- Enhancement of T-cell maturation and natural-killer-cell activity in animal models.
Summary of evidence
Laboratory and animal findings are kept separate from human clinical evidence.
Preclinical findings
Mouse infection and tumour models and in-vitro immune cell studies.
Human clinical evidence
Clinical trials of thymalfasin in chronic hepatitis B and as an adjuvant exist and underpin approvals in some jurisdictions. Trials during the COVID-19 pandemic reported mixed results. These data concern the licensed product only.
Limitations and open questions
- Not licensed by major Western regulators.
- Heterogeneous trial quality across jurisdictions.
- Peptide is highly acidic and hygroscopic; net content differs from purity.
Scientific references
Publications cited on this page. Links open the publisher or PubMed record.
No references have been published for this entry yet.
Research use only
Thymosin Alpha-1 is described here for laboratory research. It is not approved for human or veterinary use unless a regulator has said otherwise, and nothing on this page is medical advice or guidance on administration. A disclaimer does not by itself make any activity lawful. Full disclaimer.
Contact options
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