TB-500 is a synthetic peptide related to thymosin beta-4 (Tβ4), a 43-amino-acid protein and the main actin-sequestering molecule in cells. The analytical literature identifies TB-500 as the acetylated fragment Ac-LKKTETQ, the central actin-binding sequence of thymosin beta-4, rather than the full-length protein (Esposito et al., Drug Test Anal 2012). Browse the full peptide library for related compounds.
The two molecules have different evidence. The TB-500 fragment has animal and cell data only: no completed human randomised controlled trial has been identified for it, and one human trial is recruiting. Full-length thymosin beta-4 has human trials, mostly as eye drops; two phase 3 dry-eye trials posted near-identical results in both arms, and a small phase 3 corneal trial stopped early without a significant result.
Identity note from the research dataset of our partner and supplier: The catalogue listed the full 43-residue thymosin beta-4 sequence under the name TB-500, while the analytical literature identifies TB-500 as the fragment Ac-LKKTETQ, and the catalogue's formula matched neither PubChem record. Identity fields are withheld until the supplier confirms which molecule the vial contains.
