TB-500

What is TB-500?

TB-500 is a synthetic peptide marketed and studied as a fragment of thymosin beta-4 (Tβ4), a natural protein involved in the regulation of the actin cytoskeleton. Thymosin beta-4 is present in many tissues and plays an important role in cell movement, wound healing and cell survival under stressful conditions.

The name TB-500 does not denote a single standardised molecule. Different manufacturers list different fragments or lengths. For research use, it is therefore essential that the specification states the exact sequence, length and molecular mass, not just the trade name.

Proposed mechanisms

Thymosin beta-4 binds actin and affects its polymerisation. This process is the basis for cell movement, wound closure and tissue remodelling. In preclinical models, researchers have reported:

• faster closure of skin wounds;
• increased migration of keratinocytes and endothelial cells;
• a reduced inflammatory response in some models;
• a better outcome after cardiac muscle injury in animals.

These results are interesting, but they mostly come from small animal studies. The “more actin” mechanism does not yet imply a clinical effect.

What does the human literature say?

There are few data on TB-500 in humans. Thymosin beta-4 has been studied in some clinical contexts, but with different preparations and doses than those used by research laboratories. For TB-500 as a standalone compound, there are no large randomised trials confirming safety and efficacy.

This matters for interpretation: citing studies of “thymosin beta-4” is not the same as citing a specific fragment. The biology of fragments can differ.

Quality and traceability

The specification declares a purity of ≥ 98 % (HPLC), and identity is confirmed by mass spectrometry. A credible certificate of analysis contains data on the method, purity and batch number. When comparing suppliers, always request documentation for the specific batch, not a generic PDF without traceability.

You can read more about what a credible document must contain in the article How to read a certificate of analysis.

Storage

Store the lyophilized peptide at −20 °C, protected from light and moisture. After reconstitution, store it at 2–8 °C and observe the shelf life and method of use specified in the laboratory protocol. Avoid repeated freezing and thawing.

Conclusion

TB-500 is a fragment of research interest with a clear biological hypothesis but without solid clinical evidence. For research use, the exact identity of the molecule and the declared purity matter more than marketing labels.