TB-500 (Ac-LKKTETQ fragment)

Human evidence can mean a controlled clinical study, an observational study, a safety or exposure report, or evidence from a particular finished formulation. Those are different kinds of information.

No established clinical evidence for this defined material. A clinical benefit and a complete safety picture have not been established for the defined material or use reviewed here.

Preclinical means research in cells, tissues, or animals rather than in people. It can help researchers form a hypothesis, but it cannot establish a human benefit or a complete human safety profile.

Short thymosin beta-4-derived sequences, including LKKTETQ, have laboratory and animal research related to repair and inflammation. FDA found no nonclinical efficacy or toxicity studies adequate to characterize the nominated TB-500 drug substance itself.[3]

Preclinical findings do not establish outcomes in people.

Risk information may describe the compound, a finished product, a route, a population, or product-quality concerns. The cited material does not replace a current product label or an individual professional assessment.

This section is about the United States only. Status applies to a product, formulation, route, population, and use—not to a name in the abstract. A status shown here is not a recommendation or a statement about another country.

• Source/status dateJul 22, 2026

  Research only

  No FDA-approved TB-500 product was identified. In a May 2026 staff briefing prepared for the July 23-24 advisory-committee meeting, FDA said the evaluation criteria weighed against 503A Bulks List inclusion; FDA stated that no final determination would be issued until the advisory process and reviews were complete.

  Specific product form or route is not separately published in this status record.

  Open source context

The date above is the date attached to the published status record or source context. It is not necessarily the original approval date.

These prompts help organise a conversation with a qualified professional. They do not create a treatment recommendation, dose, or protocol.

• EvidenceWhich human evidence applies to the exact product, form, route, and use being discussed?
• What remains uncertainWhat is known, and what remains uncertain for this specific context?
• RisksWhich important warnings, common effects, and product-quality concerns should be discussed?
• U.S. statusWhat does the U.S. status cover, and what does it not cover?

Related means that the profiles share a topic, pathway, product context, or research question. It does not mean that they are equivalent.

• Thymosin beta-4TB-500 here is an acetylated seven-amino-acid fragment and is not full-length thymosin beta-4.

PeptideGrid review date: Jul 22, 2026. Sources support the specific sections that cite them. Publication does not imply endorsement, equivalence, or individual suitability.

1. 1

   FDA staff briefing for TB-500-related substances

   U.S. Food and Drug Administration. FDA Evaluation of TB-500-Related Bulk Drug Substances (TB-500 (Free Base) and TB-500 Acetate). Pharmacy Compounding Advisory Committee briefing document. 2026.

   U.S. Food and Drug Administration · Published May 15, 2026 · Accessed Jul 22, 2026 · Regulatory source

   Open source
2. 2

   Analytical identification of the peptide marketed as TB-500

   Esposito S, et al. Detection of a synthetic thymosin beta-4 fragment in products marketed as TB-500. Drug Testing and Analysis. 2012;4(9):733-738.

   PubMed-indexed primary study · Published Sep 1, 2012 · Accessed Jul 22, 2026 · Reference source

   Open source
3. 3

   Preclinical research on thymosin beta-4 active sites

   Sosne G, et al. Thymosin beta 4 and its active sites: anti-inflammatory, reparative, and regenerative properties. FASEB Journal. 2010;24(7):2144-2151.

   PubMed-indexed review · Published Jul 1, 2010 · Accessed Jul 22, 2026 · Systematic review

   Open source