Tb4, Timbetasin
Evidence Grade B — Strong clinical evidence. 592 published studies, 325 human. 17 registered clinical trials.
Thymosin beta-4 is a naturally occurring protein found in nearly all human cells, involved in cell movement and tissue repair. Pharmaceutical versions have been tested in clinical trials for dry eye disease, corneal wounds, and heart repair after heart attacks, with mixed results. It has no marketing authorisation. It should be distinguished from TB-500, which is a different, smaller fragment.
592 published studies: 325 human, 210 animal, 106 in-vitro, 59 reviews
Thymosin beta-4 has no current marketing authorisation. RegeneRx Biopharmaceuticals has conducted Phase II and Phase III trials of RGN-259 for dry eye disease and neurotrophic keratopathy, with mixed results. A Phase I cardiac study (RGN-352) demonstrated acceptable safety but did not advance to Phase II.
Animal studies have consistently shown effects on wound healing and tissue repair. The clinical development programme has focused on ophthalmic applications. Thymosin beta-4 should be distinguished from the 7-amino-acid fragment TB-500 (#82), which is a different molecule with no independent clinical trial data.
Research suggests thymosin beta-4's primary biological role is sequestering G-actin, a building block of the cellular skeleton, regulating cell movement and shape. Additional proposed mechanisms from preclinical research include promotion of cell survival, blood vessel formation, and anti-inflammatory effects. These mechanisms have been observed in laboratory and animal studies. Clinical translation remains under investigation.
Research suggests animal studies have consistently shown thymosin beta-4 promotes wound healing and tissue repair across multiple organ systems. Clinical development by RegeneRx Biopharmaceuticals has focused on eye conditions (RGN-259 for dry eye and corneal injuries), with Phase II and Phase III trials producing mixed results. A Phase I cardiac study showed acceptable safety but did not advance. Despite robust animal data, clinical translation has been slow and uncertain. A theoretical concern exists around potential tumour promotion, as the gene encoding thymosin beta-4 is overexpressed in some cancers. The development company appears to have limited resources for large-scale trials.
TB-500 (Thymosin Beta 4 17-23 Fragment) for Cardiovascular Biomarkers in Stable ASCVD
Assessment of the Safety and Efficacy of 0.1% RGN-259 Ophthalmic Solution for the Treatment of NK: SEER-2
Efficacy and Safety Study of Thymosin Beta 4 in Patients With Acute Myocardial Infarction
Safety and Efficacy Study of Thymosin Beta 4 in Patients With Acute Myocardial Infarction.Infarction
A Study of the Safety and Efficacy of Injectable Thymosin Beta 4 for Treating Acute Myocardial Infarction
The information on this page is provided for educational and research reference purposes only. This is not medical advice. Always consult a qualified healthcare professional before making any health-related decisions.
TB-500 has no marketing authorisation from any regulatory agency. No human clinical trials of TB-500 specifically have been conducted. The evidence base relies on animal studies of both TB-500 and its parent molecule thymosin beta-4, which are not pharmacologically equivalent. TB-500 is prohibited by WADA and is known from equine and greyhound racing contexts. Products available through unregulated channels lack pharmaceutical quality assurance. The absence of any human safety or efficacy data means that the compound's effects, risks, interactions, and appropriate dosing in humans are unknown.
ARA-290 (cibinetide) has no marketing authorisation. Phase II trials in sarcoidosis neuropathy showed improvements in corneal nerve fibre density, and a Phase II trial in diabetic neuropathy reported improved metabolic parameters and pain scores. The FDA granted Fast Track designation for sarcoidosis neuropathy. No Phase III trials have been completed. The compound represents an investigational approach to tissue repair that is distinct from existing erythropoietin-based therapies, but its clinical development remains at an early stage.
This entry reflects historical nomenclature for the compound more commonly known as BPC-157. The evidence base, regulatory status, and limitations described for BPC-157 (#81) apply identically to this compound. See compound #81 for the full assessment. No marketing authorisation. No human Phase III trials. No established human dosing or safety profile.
