Supplied strictly for in vitro laboratory research. Not for human consumption.

TB-500 is a synthetic peptide fragment of thymosin beta-4, one of the most widely studied repair-related compounds in preclinical research. Like BPC-157, its research base is largely preclinical — though its parent protein, thymosin beta-4, has a somewhat richer human-research context. This guide covers what TB-500 is and what laboratory and animal studies have examined, for research context only.

What is TB-500?

TB-500 is a synthetic peptide corresponding to the actin-binding domain of thymosin beta-4 (Tβ4) — a naturally occurring 43-amino-acid protein present in virtually every nucleated cell, where it acts as the major actin-sequestering peptide. TB-500 represents the short, active fragment (the LKKTETQ actin-binding region) that researchers use to study that isolated activity without the full Tβ4 molecule.

Mechanism studied in preclinical models

TB-500’s studied activity centres on its interaction with actin:

Actin regulation — binds G-actin (monomeric actin), modulating the balance between globular and filamentous actin that governs cell shape and movement.
Cell migration — by regulating actin dynamics, it has been studied for promoting migration of cell types involved in tissue repair, such as endothelial cells and keratinocytes, in laboratory models.
Angiogenesis — studied for stimulating endothelial cell migration and VEGF expression in models of new blood-vessel formation.
Inflammatory modulation — thymosin beta-4 has been reported to reduce neutrophil chemotaxis and macrophage infiltration in research models.

The state of the evidence

As with BPC-157, the TB-500 fragment has not completed large-scale human efficacy trials. Most preclinical work — spanning dermal wound healing, corneal repair, cardiac ischemia, and neurological injury models — has used either the full thymosin beta-4 protein or the TB-500 fragment in animal and in vitro studies. Notably, the parent protein thymosin beta-4 has progressed to Phase 3 human trials in ophthalmology, giving it a richer human-data context than the fragment itself.

TB-500 is not approved for human therapeutic use in any jurisdiction. It also appears on the WADA Prohibited List and is classified (alongside BPC-157) as an FDA 503A Category 2 bulk drug substance. It is appropriately treated as a research compound only.

TB-500 vs thymosin beta-4

It is worth distinguishing the two: thymosin beta-4 is the full 43-amino-acid native protein, while TB-500 is the shorter synthetic fragment containing its actin-binding region. The fragment’s smaller size is part of why researchers use it to isolate that specific activity in study.

Often studied alongside BPC-157

In tissue-repair research, TB-500 is frequently examined alongside BPC-157 — the two are often discussed together because they engage complementary axes: TB-500’s actin/cytoskeletal and migratory mechanisms, and BPC-157’s vascular and cytoprotective pathways. See our BPC-157 research overview.

Research and sourcing considerations

Reproducible research depends on verified identity and purity. Research-grade TB-500 should be supplied with independent HPLC purity testing (≥99% purity) and a batch-specific certificate of analysis (COA) for the specific vial supplied.

DXB Peptides supplies research-grade TB-500 for in vitro laboratory use — HPLC-tested to ≥99% purity with a batch-specific COA, cold-chain handled and delivered across the UAE.

Frequently asked questions

What is TB-500? A synthetic fragment of thymosin beta-4 (its actin-binding domain), studied in preclinical research for actin regulation, cell migration, and angiogenesis.

Is TB-500 the same as thymosin beta-4? No. Thymosin beta-4 is the full 43-amino-acid native protein; TB-500 is the shorter synthetic fragment of its active region.

Is TB-500 approved? No. It is not approved for human use, appears on the WADA Prohibited List, and its research base is largely preclinical.

What purity should research-grade TB-500 be? Look for independent HPLC testing at ≥99% purity, accompanied by a batch-specific certificate of analysis.

Important note

TB-500 is supplied strictly for in vitro laboratory research. It is not a medicine, is not approved for human use in any jurisdiction, and is not for human consumption or in vivo administration.

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What Is TB-500? Thymosin Beta-4 Fragment Research Overview