TB-500

TB-500 is a synthetic 7-amino-acid acetylated fragment (Ac-LKKTETQ) corresponding to residues 17–23 of Thymosin Beta-4, the dominant G-actin-sequestering protein in eukaryotic cells.

Full Thymosin Beta-4 is a 43-amino-acid protein. TB-500 is a 7-aa active fragment that retains the actin-sequestering and cell-migration-promoting biology at a fraction of the manufacturing cost.

Different mechanisms. BPC-157 is a 15-aa gastric-derived peptide acting through VEGF/NO/GHR pathways. TB-500 is a 7-aa Thymosin Beta-4 fragment acting through actin cytoskeleton modulation. They are commonly stacked in recovery research; no head-to-head RCT exists.

Yes. Thymosin Beta-4 and its derivatives, including TB-500, were named explicitly under Section S2 in the 2018 WADA Prohibited List update. Prohibited at all times (in-competition and out-of-competition).

No. TB-500 is not FDA-approved for any human therapeutic use. Research-grade material is supplied for laboratory use only.

Animal pharmacokinetic data report a plasma half-life around 2 hours, with longer tissue residence in cardiac and dermal sites.

TB-500 binds monomeric G-actin, sequestering it from the F-actin polymerization pool. The cellular consequence is enhanced cell migration — particularly endothelial cells and stem-cell populations involved in tissue repair. Downstream effects include VEGF upregulation, recruitment of endogenous stem cells, anti-inflammatory NF-κB downregulation, and laminin-5 deposition in epithelial healing.

BPC-157 + TB-500 is the most commonly referenced recovery research stack in community protocols, on the theory of complementary mechanisms. No published clinical RCT validates the specific combination.

Bock-Marquette et al. 2004 (Nature, PMID 15565145) showed full Thymosin Beta-4 reduced infarct size and improved ejection fraction in a mouse myocardial infarction model. TB-500 fragment retains the relevant actin-cytoskeleton biology.

Limited human safety data. Animal toxicology shows a wide therapeutic window. Theoretical concerns include unstudied effects in active malignancy (due to angiogenic + cell-migration mechanism) and pregnancy.

Reconstitute lyophilized TB-500 with USP-grade sterile diluent per laboratory protocol. The PEPPUDEX /calculator returns the volume-per-dose math.

Animal protocols vary from single-dose cardiac-MI experiments to 4–6 week dermal wound-healing studies. Community-reported research cycles cite 4–6 week loading phases at 2–5 mg/week followed by maintenance, though these are not clinical recommendations.

Because its primary biology — binding monomeric G-actin and shifting the actin equilibrium — promotes directed cell migration. Endothelial cells migrate to angiogenic sites, stem cells migrate to injury sites, and epithelial cells migrate during wound closure.

Thymosin Beta-4 was first isolated from calf thymus in 1981 by Allan Goldstein at George Washington University. TB-500 is the synthetic 7-aa active fragment, manufactured via solid-phase peptide synthesis.