Thymosin Beta 4 (TB500)

Thymosin beta-4 (Tbeta4) is a 43-amino-acid peptide that is the most abundant member of the beta-thymosin family. Despite its name (a historical artifact from its original isolation from thymus tissue), Tbeta4 is expressed in virtually all nucleated cells and is one of the most abundant intracellular peptides, with concentrations reaching 0.4 mM in some cell types. TB-500 is a synthetic version commonly used in research. The primary intracellular function of Tbeta4 is sequestration of G-actin (globular, monomeric actin), regulating the pool of actin available for polymerization into F-actin (filamentous actin). This function is critical because actin polymerization drives cell migration — a rate-limiting step in wound healing. By maintaining a reserve of polymerization-ready G-actin, Tbeta4 enables rapid cell migration when needed. The active site responsible for actin binding is the central region containing the sequence LKKTET. Beyond actin regulation, Tbeta4 has potent anti-inflammatory activity. It suppresses NF-kB signaling and reduces pro-inflammatory cytokine expression. Bock-Marquette et al. made a landmark discovery showing Tbeta4 activates Akt (protein kinase B) in cardiomyocytes, promoting survival after ischemic injury. This finding opened research into cardiac repair applications. Tbeta4 also promotes angiogenesis, hair follicle stem cell migration, and has been shown to reduce corneal inflammation and scarring.

Thymosin beta-4 (Tbeta4) is a 43-amino-acid peptide that is the most abundant member of the beta-thymosin family. Despite its name (a historical artifact from its original isolation from thymus tissue), Tbeta4 is expressed in virtually all nucleated cells and is one of the most abundant intracellular peptides, with concentrations reaching 0.4 mM in some cell types. TB-500 is a synthetic version commonly used in research. The primary intracellular function of Tbeta4 is sequestration of G-actin (globular, monomeric actin), regulating the pool of actin available for polymerization into F-actin (filamentous actin). This function is critical because actin polymerization drives cell migration — a rate-limiting step in wound healing. By maintaining a reserve of polymerization-ready G-actin, Tbeta4 enables rapid cell migration when needed. The active site responsible for actin binding is the central region containing the sequence LKKTET. Beyond actin regulation, Tbeta4 has potent anti-inflammatory activity. It suppresses NF-kB signaling and reduces pro-inflammatory cytokine expression. Bock-Marquette et al. made a landmark discovery showing Tbeta4 activates Akt (protein kinase B) in cardiomyocytes, promoting survival after ischemic injury. This finding opened research into cardiac repair applications. Tbeta4 also promotes angiogenesis, hair follicle stem cell migration, and has been shown to reduce corneal inflammation and scarring.

Equine research used loading doses of 10 mg every other day for 30 days. Rodent wound healing studies used 5-6 mcg/wound topically or 150 mcg systemically. Cardiac studies in mice used 150 mcg intraperitoneally.

Store lyophilized (freeze-dried) powder at -20°C to 4°C in a dry environment protected from light. Unreconstituted peptide is stable for extended periods when stored properly.

Once reconstituted with bacteriostatic water or an appropriate solvent, store at 2-8°C and use within the timeframe specified on the Certificate of Analysis. Avoid repeated freeze-thaw cycles.

A Certificate of Analysis documenting purity, identity, and recommended storage conditions is included with every order.