---
title: "TB-500 research summary and literature | Sable Peptides"
description: "TB-500: what the published literature covers, how it compares with BPC-157, key facts (CAS 885340-08-9, MW 889) and 5 verified PubMed citations."
canonical: https://www.sablepeptides.co.uk/research/tb-500
dateModified: 2026-10-14
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

[Research summaries](/research)

# TB-500: research summary

For laboratory research use only. Not for human or veterinary use. This page summarises published literature. It gives no advice on use.

## What the literature covers

TB-500 is a synthetic peptide modelled on the actin-binding region of thymosin beta-4 (Tβ4), a 43-residue protein that is one of the main actin-monomer-sequestering proteins in cells.

The underlying literature is about actin biology. It covers the complete amino-acid sequence of thymosin beta-4, how Tβ4 sequesters G-actin, and how profilin and Tβ4 together control actin filament assembly and nucleotide exchange.

TB-500 should not be described as identical to full-length thymosin beta-4. Check the sequence and mass on the lot's Certificate of Analysis to confirm which molecule is supplied.

## Key facts

|  | TB-500 | BPC-157 |
| --- | --- | --- |
| CAS | 885340-08-9 | 137525-51-0 |
| Formula | C38H68N10O14 | C62H98N16O22 |
| Molecular weight (g/mol) | 889 | 1419.5 |

Source: [PubChem CID 62707662](https://pubchem.ncbi.nlm.nih.gov/compound/62707662).

## TB-500 compared with BPC-157

TB-500 and BPC-157 are often paired in catalogues, but they are unrelated. TB-500 derives from thymosin beta-4, an actin-sequestering protein. BPC-157 is a 15-residue peptide described as a fragment of a gastric-juice protein. Their research literatures barely overlap.

[Full side-by-side: TB-500 vs BPC-157](/versus/bpc-157/tb-500) · [BPC-157 research summary](/research/bpc-157)

## Frequently asked questions

Is TB-500 the same as thymosin beta-4?

No. Thymosin beta-4 is a 43-residue protein. TB-500 is a shorter synthetic peptide based on its actin-binding region.

What does thymosin beta-4 do in cells?

It binds monomeric (G-) actin and keeps it from polymerising, which buffers the pool of actin available for filament assembly.

How do I confirm what TB-500 product I have?

Compare the mass-spectrometry result on the lot's CoA with the expected molecular weight (about 889 g/mol for the listed TB-500 formula C38H68N10O14).

## Published literature cited

1.  Pantaloni D, Carlier MF. (1993). How profilin promotes actin filament assembly in the presence of thymosin beta 4. *Cell*. [PMID 8252614](https://pubmed.ncbi.nlm.nih.gov/8252614/) · [doi:10.1016/0092-8674(93)90544-z](https://doi.org/10.1016/0092-8674\(93\)90544-z)
2.  Safer D, Elzinga M, Nachmias VT. (1991). Thymosin beta 4 and Fx, an actin-sequestering peptide, are indistinguishable. *J Biol Chem*. [PMID 1999398](https://pubmed.ncbi.nlm.nih.gov/1999398/) · [doi:10.1016/s0021-9258(20)64278-8](https://doi.org/10.1016/s0021-9258\(20\)64278-8)
3.  Goldschmidt-Clermont PJ, Furman MI, Wachsstock D, Safer D, Nachmias VT, Pollard TD. (1992). The control of actin nucleotide exchange by thymosin beta 4 and profilin. A potential regulatory mechanism for actin polymerization in cells. *Mol Biol Cell*. [PMID 1330091](https://pubmed.ncbi.nlm.nih.gov/1330091/) · [doi:10.1091/mbc.3.9.1015](https://doi.org/10.1091/mbc.3.9.1015)
4.  Low TL, Hu SK, Goldstein AL. (1981). Complete amino acid sequence of bovine thymosin beta 4: a thymic hormone that induces terminal deoxynucleotidyl transferase activity in thymocyte populations. *Proc Natl Acad Sci U S A*. [PMID 6940133](https://pubmed.ncbi.nlm.nih.gov/6940133/) · [doi:10.1073/pnas.78.2.1162](https://doi.org/10.1073/pnas.78.2.1162)
5.  Yu FX, Lin SC, Morrison-Bogorad M, Atkinson MA, Yin HL. (1993). Thymosin beta 10 and thymosin beta 4 are both actin monomer sequestering proteins. *J Biol Chem*. [PMID 8416954](https://pubmed.ncbi.nlm.nih.gov/8416954/) · [doi:10.1016/s0021-9258(18)54179-x](https://doi.org/10.1016/s0021-9258\(18\)54179-x)

Every citation was looked up by PMID in Europe PMC (MEDLINE) on 2026-10-14 and its title matched. Citation means the paper exists and is relevant to the compound. It does not mean the paper supports any use.

## On this site

-   [TB-500 vials, sizes and prices](/tb-500-uk)
-   [TB-500 reference record](/ref/tb-500)
-   [TB-500 UK price check](/uk-price-check/tb-500)
-   [Certificates of Analysis](/coa)

TB-500 is a synthetic peptide modelled on the actin-binding region of thymosin beta-4 (Tβ4), a 43-residue protein that is one of the main actin-monomer-sequestering proteins in cells. This page summarises 5 verified PubMed papers and compares TB-500 with BPC-157. Research use only; no human-use guidance is given.

Updated 2026-10-14