What is TB-500? Thymosin beta-4 and the research peptide explained

Thymosin beta-4 first

Thymosin beta-4 is a small protein of 43 amino acids found in almost every cell type. Its best-understood job is binding actin, the protein that cells assemble into filaments to hold their shape and to move. By holding actin in its unassembled form, thymosin beta-4 helps control when and where filaments are built.

What TB-500 is

TB-500 is a synthetic peptide modelled on thymosin beta-4, and in particular on the short region of it that binds actin. It is written TB-500, TB 500 or TB500, and the three mean the same thing.

PropertyValue

TypeSynthetic peptide

Modelled onThymosin beta-4, a 43-amino-acid protein

Key regionThe actin-binding motif

Also writtenTB 500, TB500

TB-500 and thymosin beta-4 side by side

Thymosin beta-4TB-500

OriginMade naturally in almost every cellMade by synthesis

Length43 amino acidsDepends on the supplier: see below

Molecular weightAbout 4,963 g/molStated on the certificate

Name used inThe scientific literatureResearch supply

The name TB-500 is not used consistently. Some suppliers use it for a synthetic copy of the full 43-amino-acid sequence. Others use it for a short fragment containing the actin-binding region. The two are different molecules with very different molecular weights.

The certificate settles it. A mass spectrometry result near 4,963 g/mol is the full-length sequence, and a result under 1,000 g/mol is a fragment. Reading a batch certificate shows where to find the figure.

What it has been studied for

Research interest follows from the actin connection. Because actin drives cell movement, thymosin beta-4 and peptides based on it are used in studies of:

Actin binding and the organisation of the cytoskeleton
Cell migration in culture
Blood-vessel formation in cell-based and animal models
Extracellular-matrix and tissue-associated processes in vitro

As with most research peptides, this is preclinical work. No effect in people is claimed.

TB-500 in the laboratory

Our TB-500 10mg vial is supplied pre-mixed in 3ml and should be refrigerated at 2–8°C, not frozen. It is studied alongside BPC-157 often enough that the pairing has a nickname: see BPC-157 and TB-500.

Legal status

TB-500 is sold in the UK as a research compound, for laboratory use only. Thymosin beta-4 is on the World Anti-Doping Agency prohibited list. See are peptides legal in the UK?

Common questions

Is TB-500 the same as thymosin beta-4? Not strictly. Thymosin beta-4 is the natural protein. TB-500 is a research name for a synthetic peptide based on it.

Is TB-500 a steroid? No. It is a peptide, a chain of amino acids. Steroids are a different class of molecule.

Does TB-500 need to be kept cold? In solution, yes: refrigerated at 2–8°C and never frozen. Storing peptides has the detail.

Research use onlyProducts are supplied for laboratory research and are not for human or animal consumption, diagnosis or treatment. Questions about a batch? Contact the lab with the batch number.