Overview
TB-500 (also referenced in research literature as TB500, tb-500 peptide, or Thymosin Beta-4 fragment) is a synthetic heptapeptide corresponding to the N-acetylated active fragment (amino acids 17–23) of thymosin beta-4 (Tβ4), a naturally occurring 43-amino-acid protein found ubiquitously in human and animal tissues. Thymosin beta-4 was first isolated from thymic tissue in the 1960s and has since been recognized as a master regulator of actin dynamics — the cytoskeletal processes that govern cell shape, movement, and division. The TB-500 fragment (Ac-LKKTETQ) retains the actin-binding domain of the full-length thymosin beta-4 molecule, which is responsible for the peptide's primary biological activities in preclinical research models.
Mechanism of Action
The central mechanism of TB-500 revolves around its capacity to bind monomeric G-actin (globular actin) and thereby regulate the equilibrium between G-actin and filamentous F-actin. Actin dynamics are essential for virtually every aspect of cell motility, including the directed migration of repair cells to sites of tissue injury. By sequestering G-actin, TB-500 reduces the pool available for F-actin polymerization in a spatially controlled manner, effectively enabling cells to extend lamellipodia and migrate toward chemotactic gradients. This mechanism is particularly relevant to wound healing, where fibroblasts, endothelial cells, and keratinocytes must migrate into the wound bed to initia
Research Evidence
- Binds G-actin via WH2 domain, regulating cytoskeletal dynamics and cell migration (Goldstein, 2012)
- Promotes endothelial cell differentiation and angiogenesis in dermal tissue models
- Inhibits inflammatory cytokines IL-1β and TNF-α in preclinical inflammation models
- Activates Akt survival pathway, providing cytoprotection in ischemic tissue models
- Accelerates full-thickness wound closure in rodent models (Malinda et al., 1999)
Bottom line: TB-500 has a stronger clinical research foundation than most peptides in this category — its parent molecule (full-length Thymosin Beta-4) entered human trials for wound healing and dry eye. TB-500 itself is a shorter, more targeted fragment. All current TB-500 research is preclinical; it is a research compound only.
Research Protocols & Dosage
Evidence-based research protocols, administration routes, and dosage considerations for TB-500 are detailed in the full compound profile. See also: Dosage guide for TB-500.
Sourcing & Quality
TB-500 is available from Purgo Labs with third-party COA verification and research-grade purity standards. View TB-500 at Purgo Labs.