TB 500

TB 500 is supplied as a catalogued research material in 5 mg and 10 mg.

Current FDA chemistry review supports TB-500 as N-acetyl thymosin-β4(17–23), Ac-LKKTETQ. The market name is nevertheless used inconsistently for the acetylated fragment, non-acetylated LKKTETQ, salt forms and even full-length thymosin-β4. Registry values are conditional on sequence, N-acetylation and counter-ion confirmation [1–3].

Chemical properties and registry information

Registry values apply only to the specific molecular entity, sequence, termini and material form. Batch records take precedence over family-level literature identifiers.

TB-500 is the synthetic N-acetylated peptide fragment corresponding to residues 1-43 of Thymosin Beta-4. It is distinct from the full, naturally occurring Thymosin Beta-4 protein (CAS 77591-33-4).

Research background and published evidence

Published research

Defensible contexts are LC–HRMS identity and metabolite analysis and assays performed directly with sequence-confirmed Ac-LKKTETQ. Fragment-specific results must be separated from literature on full-length thymosin-β4 or non-acetylated LKKTETQ [1–3].

Current scientific understanding

FDA found no human administration studies for TB-500, and evidence for non-acetylated LKKTETQ or full-length thymosin-β4 cannot be transferred automatically. No clinical or human-use inference is appropriate.

Technical comparison

Quality and testing

Quality information is batch- and presentation-specific. Use only the report linked to the exact size and lot. A report listed for another size, lot or similarly named material must not be treated as evidence for this product.

Chromatographic area purity, identity, net peptide or analyte content, water or counter-ion content, sterility, endotoxin and elemental impurities are different measurements. One result does not establish the others. Only tests supported by a visible, matching report should be regarded as available.

Laboratory handling and storage

Store and handle only under the conditions stated on the product label, batch CoA and SDS. Keep the container secured, correctly identified and protected from contamination. Do not infer storage, solvent compatibility or stability from a related compound.

Laboratory preparation, analytical-method selection, risk assessment, personal protective equipment and waste disposal should follow the applicable SDS and the institution’s approved procedures.

Regulatory and legal status

Sources and references

1. [1] U.S. FDA. 2026 briefing document for TB-500.
2. [2] PubChem. N-acetyl thymosin-β4(17–23) compound record.
3. [3] Primary analytical identification of TB-500. Drug Testing and Analysis.

Frequently Asked Questions

Do the CAS number and PubChem CID apply to every batch form?

Only when the exact sequence or structure, termini, conjugation, salt or counter-ion and hydration state match. The batch CoA and SDS govern; a related-compound identifier must not be substituted.

What does an analytical purity result mean?

It is method- and report-specific. For example, an HPLC area percentage is not automatically the same as identity, net content, sterility, endotoxin status or absence of elemental impurities.

How should the material be stored and handled?

Follow the exact label, batch CoA and SDS together with the institution’s risk assessment. Use only storage and stability information linked to the exact material form and batch.