Is TB-500 the same as thymosin beta-4?

Ours is, but not every product with the name is. Our vial contains the full 43-residue thymosin beta-4 sequence with an acetylated N-terminus, at 4,963.5 g/mol. Some suppliers sell a 7-residue fragment, Ac-LKKTETQ, under the same TB-500 name. That fragment weighs about 889 g/mol and covers only the actin-binding region.

The two aren’t interchangeable in an experiment. The full-length protein also contains Ac-SDKP, a tetrapeptide with its own anti-fibrotic research literature, and the fragment does not. Confirm the mass on the lot report in our COA library before comparing data across suppliers. Despite the similar name, Thymosin Alpha-1 is a different peptide. View our TB 500 peptide.