TB-500 (Thymosin Beta-4 Acetate) is a synthetic form of the naturally occurring 43–amino acid peptide thymosin beta-4, supplied in its acetate salt form for stability. It has been studied in preclinical research for its role in actin regulation, cell migration, and tissue repair–associated signaling pathways. Thymosin beta-4 is widely distributed in mammalian tissues and is involved in cytoskeletal organization and cellular movement.