Research Use Only
Thymosin beta-4
· Reviewed by Aydan Myers, Lead Chemist · Evidence tier B
Thymosin beta-4 (timbetasin; CAS 77591-33-4) is the 43-residue N-acetyl protein (average MW 4963). It is not Costides SKU TB5. TB-500 (SKU TB5) is the synthetic N-acetyl heptapeptide Ac-LKKTETQ (CAS 885340-08-9; average MW 889.0), corresponding to residues 17–23 of thymosin beta-4. Research use only; not for human or veterinary use.
Synonyms and vendor codes indexed here include TB4, Tβ4, Timbetasin, Fx peptide. This page does not describe administration or dosing.
TB-500 research · TB5 catalog listing
Key facts
| CAS Registry Number | 77591-33-4 |
|---|---|
| Molecular formula | C212H350N56O78S |
| Average molecular weight | 4963 Da |
| PubChem CID | 45382195 |
| InChIKey | UGPMCIBIHRSCBV-UHFFFAOYSA-N |
| Page type | Research identity monograph |
| Intended use | Research Use Only (reference) |
| Synonyms | TB4, Tβ4, Timbetasin, Fx peptide |
| Research notes | actin-sequestering peptide studied in tissue repair models |
| Evidence tier | B |
| Last verified | 2026-08-29 |
Is Thymosin beta-4 for human use?
No. Thymosin beta-4 (TB4) pages on Costides are Research Use Only reference materials. They are not medical advice and do not describe administration or dosing.
What is the CAS number of Thymosin beta-4?
The CAS number of Thymosin beta-4 (TB4) is 77591-33-4. Formula and molecular weight appear in the identity table when retrieved.
What is the molecular weight of Thymosin beta-4?
The average molecular weight of Thymosin beta-4 (TB4) listed on Costides is 4963 Da.
Chemical identity table
| CAS Registry Number | 77591-33-4 |
|---|---|
| Molecular formula | C212H350N56O78S |
| Average molecular weight | 4963 Da |
| PubChem CID | 45382195 |
| InChIKey | UGPMCIBIHRSCBV-UHFFFAOYSA-N |
| Synonyms | TB4, Tβ4, Timbetasin, Fx peptide |
Frequently asked questions
- What is Thymosin beta-4?
- Thymosin beta-4 (timbetasin; CAS 77591-33-4) is the 43-residue N-acetyl protein (average MW 4963). It is not Costides SKU TB5. TB-500 (SKU TB5) is the synthetic N-acetyl heptapeptide Ac-LKKTETQ (CAS 885340-08-9; average MW 889.0), corresponding to residues 17–23 of thymosin beta-4. Research use only; not for human or veterinary use. Research Use Only. Not for human or veterinary use.
- What is the CAS number of Thymosin beta-4?
- The CAS number of Thymosin beta-4 (TB4) is 77591-33-4. Formula and molecular weight appear in the identity table when retrieved.
- Is Thymosin beta-4 for human use?
- No. Thymosin beta-4 (TB4) pages on Costides are Research Use Only reference materials. They are not medical advice and do not describe administration or dosing.
- What is the molecular weight of Thymosin beta-4?
- The average molecular weight of Thymosin beta-4 (TB4) listed on Costides is 4963 Da.
- Can I buy Thymosin beta-4 from Costides?
- No. Costides does not sell the 43-residue protein timbetasin (CAS 77591-33-4). SKU TB5 is TB-500, the 7-aa fragment Ac-LKKTETQ (CAS 885340-08-9). Research use only; not for human or veterinary use.
- Where does identity data for Thymosin beta-4 come from?
- Costides indexes registry and bibliographic sources (PubChem, CAS Common Chemistry, PubMed permalinks) when available. Outcome or efficacy claims are not restated on this page.
Citations
- PubChem CID 45382195
- CAS Common Chemistry 77591-33-4
- Dysregulation of circulating damage-associated molecular patterns in diabetic foot syndrome. PMID 42440461
- DOI for PMID 42440461 PMID 42440461
- Understanding the effects of ciprofloxacin on corneal epithelial cells: a study using electric cell-substrate impedance sensing (ECIS) technology. PMID 42431294
- DOI for PMID 42431294 PMID 42431294
- PEGylated thymosin β4 is a thiol-site-specific prodrug treating myocardial infarction in vivo. PMID 42394899
- DOI for PMID 42394899 PMID 42394899