What Is TB-500 / Thymosin Beta-4?
Thymosin beta-4 is a naturally occurring 43-amino-acid actin-binding peptide. TB-500 is the name commonly used in the research-material market for a synthetic peptide related to thymosin beta-4. Published work is preclinical, and the material is supplied for laboratory research only.
Published 2026-08-22 · Updated 2026-08-22 · Reviewed by the Lana editorial team
Molecular information
Thymosin beta-4: molecular formula C212H350N56O78S, molecular weight approximately 4963 g/mol, CAS 77591-33-4. Suppliers may use the TB-500 designation for either full-length Tβ4 or a related fragment, so the analytical documentation matters.
What mechanisms have been investigated?
Thymosin beta-4 is characterised in the literature as an actin-sequestering peptide, and has been examined in cell migration and angiogenesis models.
Regulatory and research status
Not an approved therapeutic product. Prohibited in sport by WADA. Supplied as a research reference material only.