TB-500: compound identifiers, research literature, and verified purity
99.402%assayed by HPLC at Janoshik
TB-500 is sold here as thymosin beta-4 (TB4), the full-length N-acetylated 43-residue peptide, CAS 77591-33-4, which is the name the Janoshik report for this listing gives the sample. Ouralus supplies it as a lyophilized powder for laboratory research use only. The Janoshik report assayed 99.402% by third-party HPLC, and that report is published here with a key you can confirm with the laboratory yourself.
Compound identifiers
- CAS
- 77591-33-4
- Molecular formula
- C212H350N56O78S
- Molar mass
- 4963 g/mol
- Sequence
- Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser-OH
- PubChem CID
- 16132341
- UNII
- 2D5MRE3SSY
Also known asTB-500 · TB500 · TB4 · Thymosin beta-4 · Thymosin β4 · Timbetasin
What the research literature covers
The characterization below reflects published research literature only. It describes what that literature examines; it is not a statement about use in people. TB-500 is investigational research material and is not an approved product.
Thymosin beta-4 (TB4) is an N-acetylated 43-residue peptide of the beta-thymosin family, characterized in the literature as a G-actin–sequestering peptide. The name "TB-500" is used commercially for it and, by some suppliers, for a seven-residue fragment of it; this listing is the full-length peptide named on its Janoshik report.
Published work on thymosin beta-4 concerns its actin binding, its posttranslational modifications and the structural biology of the beta-thymosin family. Ouralus supplies it as a lyophilized powder for laboratory research use only.
- Extracellular matrix
TB-500 and BPC-157, side by side
These two are frequently discussed together. They are different molecules, with different sequences and different molar masses. The table states what each one is and what its latest published report assayed. It does not say which is preferable for any purpose, and nothing on this site does.
| Property | TB-500 | BPC-157 |
|---|---|---|
| What it is | Thymosin beta-4 (TB4), full-length 43-residue peptide | Synthetic 15–amino-acid peptide (pentadecapeptide) |
| Sequence | Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser-OH | Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val |
| CAS | 77591-33-4 | 137525-51-0 |
| Molar mass | 4963 g/mol | 1419.5 g/mol |
| Research areas in the literature | Extracellular matrix | Angiogenesis, Cytoprotection, Extracellular matrix |
| Assayed purity, latest report | 99.402% | 99.497% |
| Verify key | PDXV8UJEL1G4 | RMAIPH836PXJ |
Why compound identifiers matter here
The Janoshik report for this listing (task #92009) names the sample "TB-500 (TB4)" and states its measured content and HPLC purity. It prints no separate identity result, so the TB4 name on this page is the name on the report, not an identity assay.
Purity, and how to check it yourself
Purity here is a measurement, not a position. A report from Janoshik, an independent laboratory, is published for TB-500: assayed purity and net content. We do not test our own material.
- Lot
- White
- Analysed
- December 8, 2025
- Assayed purity
- 99.402%
- Testing laboratory
- Janoshik
- Verify key
- PDXV8UJEL1G4
Enter that key at janoshik.com/verify and the laboratory returns the report it issued for this batch. You are confirming the result with them, not with us. The full certificate is published as a report image on the TB-500 certificate page.
We report assayed purity and net content only. We do not run heavy-metal, microbial, endotoxin, or sterility analysis, and we do not claim it anywhere on this site.
Handling and stability
- Lyophilized
- −20°C · 24 months (sealed, desiccated)
Questions
What is TB-500?
On this listing, TB-500 is thymosin beta-4 (TB4): the full-length, N-acetylated 43-residue peptide, CAS 77591-33-4, as named on its Janoshik report. Ouralus supplies it as a lyophilized powder for laboratory research use only.
Is TB-500 the same as thymosin beta-4?
The name is used in the market both for full-length thymosin beta-4 and for a seven-residue fragment of it. The Janoshik report for this listing names the sample "TB-500 (TB4)", meaning full-length thymosin beta-4. The report prints content and purity, not a separate identity result.
Is TB-500 third-party tested?
Yes. A report from Janoshik, an independent laboratory, is published for TB-500; it prints an assayed purity of 99.402%. Its batch field matches the lot currently shipping. The certificate carries verify key PDXV8UJEL1G4, which you can confirm directly at janoshik.com/verify.
Is TB-500 an approved product?
No. TB-500 is supplied strictly as a research chemical for laboratory research use only. It is not a drug, not a supplement, and not a food, and it is not for human or animal consumption.
Selected literature
- Thymosin beta 4 interactionsBubb MR · Vitamins and Hormones · 2003PMID 12852258 ↗
- beta-ThymosinsHannappel E · Annals of the New York Academy of Sciences · 2007PMID 17468232 ↗
- The beta-thymosin enigmaSun HQ, et al. · Annals of the New York Academy of Sciences · 2007PMID 17495248 ↗
- Thymosin beta4 and its posttranslational modificationsHannappel E · Annals of the New York Academy of Sciences · 2010PMID 20536447 ↗
- Potential role of thymosin Beta 4 in liver fibrosisKim J, et al. · International Journal of Molecular Sciences · 2015PMID 26006229 ↗
- Thymosin Beta 4 Is a Potential Regulator of Hepatic Stellate CellsKim J, et al. · Vitamins and Hormones · 2016PMID 27450733 ↗
- Cardioprotection by Thymosin Beta 4Pipes GT, et al. · Vitamins and Hormones · 2016PMID 27450736 ↗
- Thymosin Beta-4 Modulates Cardiac Remodeling by Regulating ROCK1 Expression in Adult MammalsMaar K, et al. · International Journal of Molecular Sciences · 2025PMID 40362372 ↗
Research-literature characterization, provided for research context only. For laboratory research use only. Not for human consumption.