Thymosin Alpha-1
10mg
Thymosin alpha-1 is a 28 amino acid peptide first isolated from thymic tissue, corresponding to the N-terminal region of prothymosin alpha. Research has examined its reported effects on T-cell maturation and function, dendritic cell activity and cytokine regulation, and it holds pharmaceutical licences in several countries for immunomodulatory indications. Supplied as lyophilised powder, supplier-tested, with the certificate published on this page and independent third-party verification pending.
Published research on Thymosin Alpha-1 is indexed on PubMed.
Intended Use: Strictly for in-vitro laboratory research. Not for use in humans or animals. Not to be used in foods, drugs, or medical diagnostics. This product has not been evaluated by the MHRA or FDA. Buyer assumes full responsibility for safe handling and regulatory compliance.
99.76%
Purity
LAB
Certified
SAME
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Quantity
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Bacteriostatic Water 10ml
Required to reconstitute lyophilised peptides.
Research Use Only
This product is intended strictly for research and laboratory use only. Not for human consumption, medical use, or diagnostic purposes.
Certificate of Analysis
Third-party tested
Lyophilised Stability
24 months
Sealed at -20°C, light-protected
Reconstituted Stability
Up to 3 months
Stored at 2-8°C after mixing
Cold-Chain Shipping
Always
Dry-cold pack, Royal Mail Tracked 24
Important Notice
All compounds are sold individually and do not include research supplies. Products are provided in lyophilised (powder) form and require proper reconstitution before use in research settings.
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Thymosin Alpha-1 Price (UK)
Thymosin Alpha-1 10mg is £44.99 per vial, supplied from stock in the UK with a third-party HPLC certificate published on this page. UK delivery is £4.50 by Royal Mail Tracked 24, or free once your basket reaches £45 (£0.01 away at this price). Orders placed before 2pm on a working day are dispatched the same day.
| Vial | Price | Cost per mg | Availability |
|---|---|---|---|
| Thymosin Alpha-1 10mgThis page | £44.99 | £4.50 | In stock |
Prices are in GBP and shown per vial as supplied, lyophilised, for in-vitro laboratory research only. Cost per mg is given so researchers can compare vial sizes on a like-for-like basis. Stock and pricing on this table are read live from our inventory, so they match the basket. See our FAQ for delivery and payment options, and quality & testing for how each batch is verified.
Product Specifications
Research Overview
Thymosin alpha-1, also written thymosin α1 or TA1, and known by its INN thymalfasin, is a 28-residue peptide with an acetylated N-terminus, sequence Ac-Ser-Asp-Ala-Ala-Val-Asp-Thr-Ser-Ser-Glu-Ile-Thr-Thr-Lys-Asp-Leu-Lys-Glu-Lys-Lys-Glu-Val-Val-Glu-Glu-Ala-Glu-Asn (Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN), molecular formula C₁₂₉H₂₁₅N₃₃O₅₅, molecular weight 3108.28 g/mol and CAS number 62304-98-7. It is the N-terminal 28-residue fragment of prothymosin alpha, the acidic nuclear protein from which it is released by proteolysis, and it was first isolated from bovine thymus — specifically from calf thymosin fraction 5 — and sequenced by Goldstein and colleagues (Proc Natl Acad Sci USA, 1977). The N-terminal acetylation is the molecule's defining chemical feature: it blocks aminopeptidase degradation and is considered necessary for full activity. The sequence contains no cysteine and no methionine, so TA1 carries no disulfides and is spared the methionine-oxidation liability that dominates handling guidance for many other research peptides; what it does carry is a C-terminal asparagine, which makes deamidation the principal degradation route to design against.
The regulatory history is unusual for a peptide in this catalogue and worth stating precisely. Under the brand name Zadaxin, developed by SciClone Pharmaceuticals, thymosin alpha-1 (thymalfasin) is licensed as a prescription medicine in more than 35 countries, principally in Asia and the Middle East, for immunomodulatory indications most notably including chronic hepatitis B. The evidence base includes randomised controlled trials such as Chien and colleagues' 98-patient trial in chronic hepatitis B (Hepatology, 1998), and the history is reviewed by Camerini and Garaci (Expert Opin Biol Ther, 2015). It has never been licensed in the United Kingdom, the European Union or the United States. That asymmetry matters for researchers: a compound with a genuine pharmaceutical dossier in some jurisdictions remains an unlicensed substance in others, and no thymosin alpha-1 product is an approved medicine in the UK.
Mechanistically, the most cited modern work centres on toll-like receptor signalling rather than a classical single receptor. Romani and colleagues reported in Blood (2004) that thymosin alpha 1 activates myeloid dendritic cells for Th1-type responses through a TLR9-dependent, MyD88-mediated signalling pathway, an observation that reframed TA1 as an endogenous regulator of innate immune sensing rather than a simple T-cell maturation factor. Around that anchor sit the older T-cell literature — maturation, differentiation and function of thymocytes and peripheral T cells — alongside reports of natural killer cell activity and broad cytokine regulation, reviewed by Garaci (Ann N Y Acad Sci, 2007). The most active current direction is oncology: recent studies examine TA1 in combination with immune checkpoint inhibitors, including a 2025 retrospective analysis in platinum-resistant recurrent ovarian cancer (Wang et al., Cancer Manag Res, 2025).
The honest position on evidence follows. The licensed indications for Zadaxin are prescription medicine uses in specific jurisdictions, and nothing on this page describes or endorses any human use; the material supplied here is for in-vitro laboratory research only. Much of the older immunology literature is small, heterogeneous and in places unreplicated, and the recent checkpoint-inhibitor combination data are largely retrospective. Thymosin alpha-1 is supplied as lyophilised powder, batch UKPL-9504, at 99.76% purity by HPLC with the supplier certificate of analysis, published on the product page, with independent third-party verification pending.
Product Specifications
Laboratory Handling
- Store lyophilised vials at -20°C, protected from light and moisture. Reconstituted solution should be held at 2-8°C and used within 4 weeks.
- Reconstitute with bacteriostatic water introduced slowly down the inner glass wall, never directly onto the lyophilised cake. Swirl gently until fully dissolved; never shake or vortex.
- Work under aseptic conditions with sterile syringes and alcohol-swabbed stoppers. The sequence contains no cysteine or methionine, so no disulfide or oxidation-specific handling is required.
- Protect the C-terminal asparagine from deamidation: keep reconstituted solutions cold, minimise time at room temperature, and prepare single-use aliquots rather than repeatedly accessing one vial.
Frequently Asked Questions
What is Thymosin Alpha-1?
Thymosin alpha-1 (TA1), INN thymalfasin, is a 28-residue peptide with an acetylated N-terminus, sequence Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN, molecular weight 3108.28 g/mol, CAS 62304-98-7. It was first isolated from bovine thymus as a component of thymosin fraction 5 and characterised by Goldstein and colleagues (Proc Natl Acad Sci USA, 1977), and it corresponds to the N-terminal fragment of prothymosin alpha, the acidic nuclear protein from which it is proteolytically derived. The acetylated N-terminus is chemically significant: it blocks aminopeptidase attack and is generally considered to be required for full biological activity. The sequence contains no cysteine and no methionine, so the molecule carries no disulfides and is spared the oxidation liabilities that dominate handling guidance for many other research peptides; the residue to watch is instead the C-terminal asparagine, which deamidates in solution. Unlike most of this catalogue, TA1 has an extensive pharmaceutical history rather than a purely preclinical one — as Zadaxin (SciClone) it is licensed as a prescription medicine in more than 35 countries for immunomodulatory indications including chronic hepatitis B, though it has never been licensed in the UK, the EU or the United States. Supplied here as lyophilised powder for in-vitro laboratory research use only.
Thymosin Alpha-1 vs TB-500
The two compounds share a name and a tissue of origin, and essentially nothing else. Thymosin alpha-1 is a 28-residue, N-terminally acetylated peptide of 3108.28 g/mol whose literature concerns the immune system: toll-like receptor signalling on dendritic cells (Romani et al., Blood, 2004), T-cell maturation and cytokine regulation. TB-500 is the research-market name for a synthetic fragment of thymosin beta-4, a 43-residue acetylated polypeptide of 4963.4 g/mol (CAS 77591-33-4) whose literature concerns actin: G-actin sequestration, cell migration and angiogenesis, with the LKKTETQ actin-binding motif at its core (Philp et al., FASEB J, 2003). The two act through entirely different pharmacology — TA1 signals through TLR-mediated pathways on antigen-presenting cells, whereas thymosin beta-4 works intracellularly on the actin cytoskeleton with no dedicated cell-surface receptor — and their papers cite different literatures, immunology versus cell-motility and wound models. A researcher choosing between them is choosing between an immunology tool and a cytoskeletal tool, not between two members of one family.
Thymosin Alpha-1 Research Applications
Thymosin alpha-1 is studied as an immune-modulatory peptide across four overlapping areas. First, T-cell biology: the early literature, reviewed historically by Garaci (Ann N Y Acad Sci, 2007), describes effects on T-cell maturation, differentiation and function in thymocyte models. Second, innate immunity: Romani and colleagues (Blood, 2004) showed that TA1 activates dendritic cells through TLR9-dependent, MyD88-mediated toll-like receptor signalling, with downstream Th1 cytokine induction, and related work reports natural killer cell activation. Third, cytokine regulation: TA1 is used to probe IL-2, interferon-gamma and other cytokine networks in cell-culture systems. Fourth, oncology: recent literature studies TA1 in combination with immune checkpoint inhibitors, including a 2025 retrospective analysis in platinum-resistant recurrent ovarian cancer by Wang and colleagues (Cancer Manag Res, 2025). The honest boundaries: the licensed indications are prescription medicine uses in specific jurisdictions; this material is supplied strictly for in-vitro laboratory research; and much of the older literature consists of small, heterogeneous studies whose findings have not all been reproduced.
Reconstitution Guide
Allow the vial to reach room temperature, then sterilise the rubber stopper of both the peptide vial and the bacteriostatic water vial with an alcohol swab. Draw the bacteriostatic water into a sterile syringe and inject it slowly down the inner glass wall of the peptide vial, never directly onto the lyophilised powder. Swirl gently in a slow circular motion until fully dissolved; the solution should be clear and colourless. Do not shake or vortex. The sequence contains no cysteine, so no disulfide handling is required, and no methionine, so oxidation is a lesser concern than for many peptides — but the C-terminal asparagine is deamidation-prone, so reconstitute promptly, avoid introducing excess air, and refrigerate immediately after labelling the vial with the reconstitution date.
See our full peptide reconstitution guide and reconstitution calculator for step-by-step protocol.
Storage Instructions
Lyophilised vials should be stored at -20°C, protected from light and moisture, and remain stable for up to 24 months. Once reconstituted with bacteriostatic water, store the solution at 2-8°C (standard refrigerator) and use within approximately 4 weeks. For longer storage, prepare single-use aliquots at -20°C and avoid repeated freeze-thaw cycles. The degradation route to design against is deamidation of the C-terminal asparagine, which is accelerated in solution at higher pH and temperature — keep the solution cold, minimise time at room temperature, and never store the vial in contact with alkaline solutions. Handle under sterile laboratory conditions throughout.
Frequently Asked Questions
Research References
Related Research Compounds
Thymosin Alpha-1
10mg · £44.99