Peptide reference
TB-500
Thymosin Beta-4 ·Thymosin β4 ·Tβ4 ·TB4 ·TB-500 (synthetic Tβ4 fragment)
What cited sources report about TB-500 / Thymosin Beta-4
TB-500 is the name commonly applied in unregulated channels to a synthetic peptide derived from the actin-sequestering region of thymosin beta-4 (Tβ4), a 43-44 amino-acid endogenous peptide. The peptide is currently under review by the FDA Pharmacy Compounding Advisory Committee (PCAC), with a public meeting scheduled for July 23, 2026. As of the cited literature, TB-500 has no FDA-approved indication and no marketing authorization in any major jurisdiction. The summaries below report what individual cited sources state; this page does not assert claims beyond what those sources report.
Bock-Marquette et al. (2023) — International Immunopharmacology
A review from the University of Pecs Department of Biochemistry and Medical Chemistry, in collaboration with UT Southwestern Medical Center and the Gladstone Institute, surveyed preclinical evidence on thymosin beta-4 in cardiac development and adult repair. The authors described mouse-model observations in which intravenous TB4 administration after coronary-artery ligation was associated with myocyte survival and altered epicardial morphology. They framed the synthesis as a hypothesis-driven research direction toward regenerative therapies rather than clinical recommendation.
In adults, the peptide enhances myocyte survival and improves cardiac function after coronary artery ligation.
Maar et al. (2021) — Cells
A narrative review from the University of Pecs introduced thymosin beta-4 as a 43-amino-acid secreted peptide expressed during embryonic development and surveyed preclinical reports on its actions in cardiac progenitor activation, cell migration, and survival. The authors observed that exogenous progenitor-cell strategies for tissue regeneration appear limited and proposed developmentally relevant small molecules — including TB4 — as candidates for further investigation.
In this review, we introduce Thymosin beta-4, a 43aa secreted peptide fulfilling our hopes and capable of numerous regenerative achievements via systemic administration in the heart.
ReGenTree LLC (2007–2009) — ClinicalTrials.gov NCT00598871
A registered Phase 2, randomized, double-mask, placebo-controlled, dose-response trial of thymosin beta 4 in diabetic patients with corneal wounds, sponsored by ReGenTree LLC and run with PPD Development. The protocol was terminated owing to slow recruitment and a results record was posted in 2010. The study illustrates that TB4 has been investigated under formal IND-style oversight in ophthalmic indications.
A Randomized, Double-Mask, Placebo-Controlled, Dose Response, Phase 2 Study of the Safety and Efficacy of Thymosin Beta 4 in the Treatment of Diabetic Patients’ Corneal Wounds Resulting From Epithelial Debridement During Vitrectomy.
PubChem CID 16129770 — National Center for Biotechnology Information
The PubChem compound record for thymosin beta-4 catalogues the 43-amino-acid endogenous peptide, aggregating synonym sets and links to underlying chemical and biological literature. The record helps disambiguate TB-500 (a synthetic analog/fragment commonly sold under that trade name) from full-length Tβ4 used in registered clinical trials.
Coverage notes
The peer-reviewed evidence base for TB-500 conflates two distinct entities: full-length thymosin beta-4 (the subject of registered clinical trials such as NCT00598871) and the synthetic peptide fragment commonly sold as “TB-500.” Most cited preclinical evidence pertains to full-length Tβ4 in animal models. No FDA-approved indication exists for either entity and no FDA briefing document is publicly indexed under the FDA’s PCAC archive at the time this page was compiled; this page will be updated when the July 2026 PCAC briefing materials are released.