TB-500

What Is TB-500?

TB-500 is a synthetic 43-amino-acid peptide corresponding to the full amino acid sequence of thymosin beta-4 (Tβ4), an endogenous intracellular protein. Tβ4 is described in published biochemistry literature as the primary G-actin sequestering peptide in mammalian cells, it binds monomeric (globular) actin and modulates the equilibrium between G-actin and F-actin (filamentous, polymerized) forms.

In published research literature, TB-500 is examined in relation to actin cytoskeletal dynamics, cell migration mechanisms, and angiogenic signaling pathways. The actin-binding function is cited in published research as the structural basis for downstream effects observed in cell migration, angiogenesis, and cytoskeletal-remodeling research models.

TB-500 in Plain Language

A non-technical overview of what TB-500 is, what researchers have studied it for, what early evidence suggests, and what cannot be claimed about it. For research and educational purposes only.

At a glance

TB-500 is the active part of a natural protein called thymosin beta-4, which the body uses to move cells into damaged areas and repair tissue after injury. In research, scientists study it for how it might support healing in tendons and muscles, in the eyes (especially dry eye and corneal injuries), and in the heart after a heart attack.

Pharmaceutical-grade versions of this same protein (made separately from the product sold here) have advanced into human clinical trials. The compound sold here is a research chemical, not a pharmaceutical or therapeutic product, and is not for human or animal use.

What it is

TB-500 is a synthetic 43-amino-acid peptide. It corresponds to the full sequence of thymosin beta-4 (Tβ4), a small protein that is naturally present inside almost every cell type in mammals.

Tβ4 is best known in published biochemistry as the principal “actin-sequestering” peptide, meaning it binds the structural protein actin and helps regulate how cells build, dismantle, and reshape their internal scaffolding.

Researchers commonly study TB-500 in laboratory contexts related to cell migration, wound healing models, blood-vessel formation, and cardiac (heart) tissue repair models. Most of what is known about it comes from animal studies and cell-based experiments rather than from large human trials.

Research areas being investigated

• Cell-shape and movement research: Studied in cell experiments looking at how Tβ4 binds actin and influences cell migration in wound and tissue-remodeling models.
• Wound-healing research: Examined in animal and cell models of skin, corneal (eye surface), and gut wound repair.
• Blood-vessel research (angiogenesis): Investigated for effects on endothelial cell migration and capillary-formation assays in laboratory models.
• Cardiac repair research: Studied in animal models of heart-attack injury for effects on heart-muscle cell survival and post-injury tissue remodeling.
• Inflammation research: Examined in preclinical models for effects on inflammatory markers such as TNF-α, IL-6, and IL-1β.
• Hair-follicle and corneal research: A smaller body of preclinical work has explored Tβ4 in hair-cycle and ocular surface models.

What the research suggests so far

Animal / preclinical findings. Most published TB-500 / Tβ4 evidence comes from rodent and other animal models. In these studies, researchers have reported observations consistent with faster cellular migration in wound-healing models, increased capillary-tube formation in angiogenesis assays, and protective effects in animal models of myocardial infarction (heart attack).

These findings are commonly described in published research as connected to Tβ4’s actin-binding role and downstream cytoskeletal signaling. They do not, on their own, demonstrate the same effects in humans.

Cell / lab findings. In cell-culture work, published research has characterized Tβ4’s 1:1 binding to monomeric G-actin at residue-level resolution, with downstream effects on the G-actin / F-actin (monomer / filament) equilibrium. Cell-migration scratch assays, capillary-tube formation in Matrigel, and reductions in pro-inflammatory cytokine expression are all reported in the published literature.

These mechanistic studies help researchers form hypotheses about how Tβ4 might act in tissue, but they are several steps removed from clinical outcomes.

Human findings. Human evidence for TB-500 / Tβ4 is limited. A small number of early-phase human studies have examined topical or ophthalmic Tβ4 formulations, for example for dry eye and neurotrophic keratopathy under the development name RGN-259, with reports describing acceptable short-term safety profiles.

There are no large, published Phase III randomized controlled trials demonstrating efficacy for any condition, and TB-500 is not approved by the FDA, EMA, or other major regulators for any use.

Limitations of the evidence. The bulk of TB-500 / Tβ4 literature is preclinical. Long-term human safety data, large-scale efficacy trials, and standardized dosing studies are lacking. Independent replication across many laboratories is uneven. Reviewers in the recent peer-reviewed literature have specifically called out the need for larger, more rigorous human studies before any therapeutic conclusions can be drawn.

Research relevance

TB-500 is most often discussed in research involving actin cytoskeletal dynamics, cell-migration mechanisms, wound-healing models, angiogenesis assays, cardiac repair models, and anti-inflammatory signaling. Most published findings are preclinical, so it should not be presented as a proven treatment for any condition.

Its scientific interest lies in its potential use as a research tool for studying cytoskeletal biology and tissue-repair signaling in the laboratory.

What cannot be claimed about TB-500

• It cannot be claimed to treat, cure, heal, or repair any human or animal condition.
• It cannot be claimed to repair tendons, ligaments, joints, muscles, or hearts in humans.
• It cannot be claimed to regrow hair, restore eyesight, or reverse aging.
• It cannot be claimed to reduce pain, accelerate recovery from injury, or improve athletic performance.
• It cannot be claimed to be safe or effective for human or veterinary use.
• It cannot be claimed to be approved by the FDA or any other regulatory authority.

Summary

TB-500 is a synthetic 43-amino-acid peptide identical in sequence to thymosin beta-4 (Tβ4), an actin-binding protein found inside most mammalian cells. It is studied in laboratory and animal research related to cell migration, wound-healing models, blood-vessel formation, and cardiac tissue repair models. Published evidence comes mainly from rodent and cell-culture experiments; human evidence is limited to small early-phase studies of related Tβ4 formulations such as ophthalmic RGN-259.

TB-500 is not approved by the FDA or any other regulatory authority and is sold here strictly as a research-use-only chemical for laboratory investigation. It is not intended for human consumption, medical use, or veterinary use.

Short version

TB-500 is a synthetic peptide identical to thymosin beta-4, an actin-binding protein. It is most often studied in animal and cell-based research on cell migration, wound healing, blood-vessel formation, and cardiac repair. Human evidence is limited and it is not approved for any medical use. Sold for research and laboratory use only.

Source notes

• Ebrahim AS, et al. Reparative Outcomes in Corneal Infection: Linking Adjunctive Tβ4 Treatment to Nerve Regeneration and Visual Function. Investigative ophthalmology & visual science, 2026. (PubMed PMID: 42283548.)
• Lachowicz JI, et al. Zinc Coordination by Thymosin β4: Structural Determinants and Functional Implications. International journal of molecular sciences, 2026. (PubMed PMID: 41751875.)
• Jin Z, et al. Mechanistic study of the Tβ4/SLC7A11 signaling pathway regulating breast cancer evolution. Cellular signalling, 2025. (PubMed PMID: 40912522.)
• Goldstein AL, Hannappel E, Kleinman HK. Thymosin β4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med, 2005, review article. (PubMed PMID: 16182610.)
• Bock-Marquette I, et al. Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature, 2004, animal study. (PubMed PMID: 15525990.)
• Smart N, et al. De novo cardiomyocytes from within the activated adult heart after injury. Nature, 2011, animal study examining Tβ4 priming and epicardial progenitor mobilization.
• Sosne G, et al. Thymosin β4 ophthalmic solution for dry eye: a randomized, placebo-controlled, Phase II clinical trial. J Ocul Pharmacol Ther, 2015, small early-phase human ophthalmology study (RGN-259).
• Crockford D, et al. Preclinical and clinical studies of thymosin β4 in wound healing and cardiovascular disease. Ann N Y Acad Sci, 2010, review article.
• Kleinman HK, Sosne G. Thymosin β4 promotes dermal healing. Vitam Horm, 2016, review of preclinical and early-phase work in skin repair.

Source types: entries 1, 5, 6 are review articles; entries 2, 3 are animal studies; entry 4 is an early-phase human ophthalmology trial of an ophthalmic Tβ4 formulation.

SEO meta description

TB-500 (synthetic thymosin beta-4) is a 43-amino-acid peptide studied in preclinical research on actin dynamics, wound healing, and cardiac repair. Research-use only.

Reminder. BioChain USA sells TB-500 strictly as a research-use-only chemical for qualified laboratory and educational use. It is not intended for human consumption, medical treatment, veterinary treatment, diagnosis, prevention, or cure of disease.

Certificate of Analysis (COA)

• COA provided where available for the specific batch shipped.
• The batch COA is the authoritative reference for analytical methods, purity data, and lot-specific testing for that shipment.
• COA information is batch-specific and is not interchangeable between lots.

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