Last reviewed: October 2026 · Cleared Peptides research team
Thymosin Alpha-1 (Tα1, thymalfasin) is a 28-amino-acid, N-terminally acetylated peptide first isolated from thymosin fraction 5, a calf-thymus extract, by Allan Goldstein and colleagues in 1977. It is a widely used reference peptide in immunology research.
Thymosin Alpha-1 Structure and Identifiers
| Name | Thymosin Alpha-1 |
|---|---|
| Synonyms | Tα1; thymalfasin |
| CAS number | 62304-98-7 |
| PubChem CID | 16130571 |
| Molecular formula | C129H215N33O55 |
| Molecular weight | ≈3108.3 g/mol |
| Length | 28 amino acids, N-acetylated |
| Form | Lyophilized powder |
Structure
Tα1 is derived from the N-terminus of prothymosin α. It is highly acidic and largely unstructured in water, adopting helical conformations in membrane-mimetic environments — a property studied in peptide–membrane interaction research.
Published In-Vitro Research Areas
- Toll-like receptor (TLR) signaling in dendritic cells and macrophages
- T-cell maturation and differentiation assays
- Cytokine-expression studies
Compare with Thymalin, a thymus-derived peptide complex.
This summary describes laboratory research only and makes no claim about effects in humans or animals.
Purity Testing and Storage
Every lot of Thymosin Alpha-1 supplied by Cleared Peptides is tested by an independent laboratory for identity and purity (or composition, for multi-component preparations), and the lot Certificate of Analysis is published on our COA page. Store lyophilized Thymosin Alpha-1 at −20 °C, sealed, dry and protected from light. Allow the vial to reach room temperature before opening and minimize freeze–thaw cycles. Handle according to your institution’s chemical-hygiene procedures.
Research materials referenced in this guide
Frequently Asked Questions
Is Thymosin Alpha-1 the same as thymalfasin?
Yes. Thymalfasin is the nonproprietary name for synthetic Thymosin Alpha-1 (CAS 62304-98-7).
Is Thymosin Alpha-1 related to TB-500?
Both are thymosins, but Tα1 (28 aa) and Thymosin Beta-4/TB-500 (43 aa) are unrelated in sequence and function.
Is Thymosin Alpha-1 for human use?
No. Cleared Peptides supplies Thymosin Alpha-1 for laboratory research use only; it is not for human or veterinary use.
Selected References
Peer-reviewed literature on the compounds discussed in this guide, listed as scientific background for laboratory researchers. Citation does not imply endorsement by the authors or any use other than in-vitro research.
- Cheng Y, et al. Identification and determination of structurally related peptide impurities in thymalfasin by liquid chromatography-high-resolution mass spectrometry. Anal Bioanal Chem. 2022;414(28):8035-8045. PubMed 36207535 · DOI
- Hoch K, et al. Structures of Thymosin Proteins. Vitam Horm. 2016;102:1-24. PubMed 27450728 · DOI
Laboratory note: solubility depends on salt form and solvent. This guide does not state a single solubility figure. Handling of lyophilized material is described in the peptide storage guide.
Research Use Only Notice
This guide is provided for educational and laboratory reference purposes. It summarizes published, primarily in-vitro and structural research literature and does not describe, recommend or imply any use in humans or animals. Products sold by Cleared Peptides are for laboratory research use only; they are not drugs, foods, cosmetics or dietary supplements, are not FDA-approved, and are not intended to diagnose, treat, cure, mitigate or prevent any disease. No dosing, administration or therapeutic information is provided.
