TB-500 — Compound Overview

What is TB-500?

TB-500 is a synthetic peptide corresponding to the actin-binding segment of thymosin beta-4 (Tβ4), a 43-amino-acid protein found in most mammalian cells. The commonly supplied research fragment is the acetylated heptapeptide LKKTETQ (residues 17–23 of Tβ4). TB-500 is produced synthetically and is chemically distinct from full-length thymosin beta-4, although the two names are often conflated in informal sources.

Chemistry and structure

The TB-500 fragment carries CAS registry number 885340-08-9, molecular formula C38H68N10O14 and a molecular weight of approximately 889.0 g/mol. The N-terminal acetyl group mimics the corresponding region of the parent protein. The certificate of analysis for each batch records the exact form and counter-ion tested.

TB-500 in the research literature

Thymosin beta-4 — the parent protein — is one of the major actin-sequestering molecules in mammalian cells and has an extensive preclinical literature covering actin dynamics, cell migration and tissue models. The LKKTETQ fragment is studied specifically as the actin-binding motif of that protein. As with most research peptides, the literature is preclinical; controlled human data for the synthetic fragment are lacking.

Regulatory status

TB-500 is not an approved medicine in any jurisdiction and is prohibited in sport by WADA. Index Peptides supplies it strictly for in-vitro laboratory research — not for human or veterinary use.

Form, handling and storage

Supplied as a lyophilised powder in a sealed vial. Store at -20°C, desiccated and protected from light, per the batch record. Handling is the responsibility of the qualified researcher.

Batch documentation at Index Peptides

Every released batch is HPLC purity tested and LC-MS identity confirmed, with the certificate of analysis published on the product page and verifiable by lot number.

Frequently asked questions

References

• PubChem — TB-500 fragment (CAS 885340-08-9)
• WADA Prohibited List