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eHealthTutorial — Research Peptide Reviews
Preclinical fragment • FDA caution

Thymosin β4 fragment and metabolite research

TB-500 (Thymosin Beta-4 Fragment)

TB-500 is a short thymosin beta-4-derived fragment, not the full-length protein. Its metabolite and fibroblast studies do not establish human wound or recovery treatment.

Explore the research
Generic research visual — not a commercial product
Compound typeAcetylated LKKTETQ fragment designation
Evidence baseIn vitro/metabolite and rat studies
Regulatory contextInvestigational / Not FDA-approved
Page purposeResearch overview
Why there is no compound calculator on this page

FDA has not identified human exposure data for the nominated TB-500 fragment and flags peptide impurities/immunogenicity. A syringe diagram would not validate the fragment identity or safety.

Research overview

What is TB-500 (Thymosin Beta-4 Fragment)?

TB-500 is used for a short acetylated fragment derived from a region of thymosin beta-4. Full-length thymosin beta-4 has many more residues and a separate evidence record. The exact parent fragment, acetylation, and metabolites matter for any laboratory comparison.

What has research examined?

A primary analytical and experimental study measured TB-500 and metabolites in cell systems and rats. In a fibroblast assay, a particular metabolite (Ac-LKKTE) showed significant wound-healing activity, not the parent TB-500. FDA states it has no identified human exposure data for the proposed fragment drug product and lacks important safety information.

Important limitation

In vitro scratch/wound assay effects and rat metabolism cannot establish clinical recovery. Full-length TB-4 results are not fragment results. No use or preparation is advised.

Research references

Calculation boundary

FDA has not identified human exposure data for the nominated TB-500 fragment and flags peptide impurities/immunogenicity. A syringe diagram would not validate the fragment identity or safety.

For research purposes only. This page is educational and is not medical or veterinary advice or a recommendation to purchase, prepare, administer, or use any product.