Research compound overview

TB-500 and Thymosin Beta-4: Structure, Research Overview and Specifications

TB-500 is the name used for synthetic peptides related to thymosin beta-4 (Tβ4), a small actin-binding protein found in almost every human and animal cell. The name is used loosely: depending on the supplier it can mean the full 43-amino-acid Tβ4 protein or a short 7-amino-acid fragment of it. This page explains the difference, summarises the published research on Tβ4 and gives the specifications of the material we supply.

Related toThymosin beta-4

Full Tβ443 aa · ≈ 4963 Da

FragmentAc-LKKTETQ · ≈ 889 Da

Key roleG-actin binding

View TB-500 10mg →Read the research ↓

For in vitro research use only. Not for human or animal use. Nothing on this page is medical advice.

What is TB-500?

Thymosin beta-4 is a 43-amino-acid peptide first characterised as part of the “thymosin” family isolated from thymus tissue. Its best-known role is binding G-actin (monomeric actin). That regulates actin polymerisation, which cells need in order to move, change shape and divide. Because cell migration is central to tissue repair, Tβ4 has been studied widely in wound-healing, cardiac and corneal models.

“TB-500” is a trade name rather than a formal chemical name. It appeared originally in the veterinary and equine field.

TB-500 vs thymosin beta-4: fragment or full protein?

A 2012 study synthesised and characterised the N-acetylated 17–23 fragment after identifying it in products sold as TB-500 (see references). Always check a supplier’s Certificate of Analysis to confirm which molecule you are buying. The mass-spectrometry result shows it immediately.

Chemical data: what we supply

Proposed mechanisms studied

• Actin sequestration. Tβ4 is the main G-actin-sequestering peptide in many cell types. It controls the pool of actin available for building filaments.
• Cell migration. In vitro, Tβ4 promotes the migration of endothelial cells, keratinocytes and other cell types.
• Integrin-linked kinase (ILK) and Akt signalling. Cardiac research has linked Tβ4 to ILK activation and downstream survival signalling.
• Angiogenesis and inflammation. Studies describe effects on blood-vessel formation and on inflammatory signalling in injury models.

What the published research shows

Cardiac models

A frequently cited 2004 paper in Nature (Bock-Marquette et al.) reported that Tβ4 activated integrin-linked kinase and promoted cardiac cell migration and survival, with improved outcomes after experimental myocardial infarction in mice. Later work examined Tβ4 alongside cardiac reprogramming approaches.

Wound and corneal models

Animal and in vitro studies have described faster re-epithelialisation and wound closure. Tβ4 has been investigated in eye-surface (corneal) research.

Human data

Full-length Tβ4 has been tested in a small number of early-phase clinical studies for specific indications, such as eye and wound applications. The short “TB-500” fragment has no published human trials.

Limitations of the evidence

• Most mechanistic and efficacy data concern full-length Tβ4. They cannot automatically be applied to the 7-amino-acid fragment.
• The preclinical findings have not been confirmed in large controlled human trials.
• Reviewers note that high Tβ4 expression has been associated with tumour progression in some cancer studies, which is a reason for caution.

Regulatory status

TB-500 and thymosin beta-4 are not licensed medicines in the UK and are not approved by the MHRA, FDA or EMA. They are prohibited in sport by the World Anti-Doping Agency (WADA). Sterling Research supplies TB-500 only as a research reagent for in vitro laboratory use.

Storage and handling in the lab

• Store lyophilised powder at −20 °C, sealed and protected from light and moisture.
• Let the vial reach room temperature before opening to limit condensation.
• Prepare solutions to your laboratory’s validated protocols, with appropriate PPE and aseptic technique.
• Avoid repeated freeze–thaw cycles of solutions. Aliquot where your protocol allows.

Frequently asked questions

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

Not always. “TB-500” is used both for full-length thymosin beta-4 (43 amino acids, about 4963 Da) and for its short acetylated fragment Ac-LKKTETQ (about 889 Da). Check the mass-spectrometry result on the Certificate of Analysis.

What does thymosin beta-4 do in cells?

Its main known role is binding monomeric actin. That regulates the actin cytoskeleton and, through it, cell movement and shape.

Is TB-500 approved as a medicine?

No. It is not approved by the MHRA, FDA or any other drug regulator.

Is TB-500 banned in sport?

Yes. WADA prohibits TB-500 and thymosin beta-4 for athletes.

What is the difference between TB-500 and BPC-157?

They are unrelated molecules. TB-500 is related to the actin-binding protein thymosin beta-4. BPC-157 is a 15-amino-acid peptide derived from a gastric-juice protein. See our BPC-157 overview.

References

1. Bock-Marquette I, et al. Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432:466–472. PubMed 15565145
2. Synthesis and characterization of the N-terminal acetylated 17–23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential. Drug Test Anal. 2012. PubMed 22962027
3. Cardiac repair with thymosin β4 and cardiac reprogramming factors. PubMed 23050819

This page is for scientific information only. Sterling Research Group Ltd supplies TB-500 strictly for in vitro laboratory research. Not for human or animal use, and not for diagnostic or therapeutic purposes.