TB-500: What It Is and What It Does

What TB-500 is

TB-500 is a lab-made piece of a natural protein your body already uses, called thymosin beta-4. It is supplied as an analytical-grade reference material for laboratory research.

Where it comes from

TB-500 is based on thymosin beta-4, a 43-amino-acid peptide first isolated from the thymus gland in the early 1980s, which is where the 'thymosin' name comes from. Researchers initially thought it was a thymic hormone, but later found it almost everywhere in the body, including in wound fluid and blood platelets, where it acts as a key manager of the cell's internal scaffolding. TB-500 is the lab-made version of the peptide's active, actin-binding region, valued in research because that short stretch carries much of thymosin beta-4's repair-related activity.

What it does — in plain terms

Your body keeps thymosin beta-4 on hand for building and repair jobs — it helps move repair cells to where they're needed and encourages new blood vessels to form. TB-500 is the active fragment of that protein. So research looks at it for wound healing and recovery: basically helping the body's 'construction crew' cells reach an injury and start rebuilding. It's frequently studied alongside BPC-157 for that reason.

How it works

The clearest way to picture thymosin beta-4, and therefore TB-500, is as a manager of actin, one of the main building blocks cells use to construct their internal skeleton. Thymosin beta-4 is the body's principal actin-sequestering peptide: it holds a reserve of actin subunits ready to be released when a cell needs to change shape and crawl. Since crawling toward an injury is the first thing repair cells must do, this actin-handling role sits at the center of the peptide's biology.

From that starting point, the literature describes several repair-related threads. By supporting cell migration, thymosin beta-4 appears to help repair cells reach injured tissue faster. It is also repeatedly linked to angiogenesis, the growth of new blood vessels that an injured area needs for oxygen and nutrients, and to a dampening of inflammation and excess scarring in various organ models. This combination is why it is studied across skin, eye, heart, kidney, and liver injury.

It is worth being precise about what TB-500 is. Research material sold under that name corresponds to the active, actin-binding fragment of thymosin beta-4 rather than the full protein, and it is frequently studied side by side with BPC-157 because both are explored as tissue-repair tools. Importantly, most of this work is preclinical (cell cultures and animal models), so it describes what researchers observe in the laboratory, not proven effects in people.

What the research shows

Thymosin beta-4 has an unusually broad repair literature, spanning skin, cornea, heart, kidney, liver, and more, but it is important to stay clear-eyed about the level of evidence. The great majority of this work is preclinical (cell and animal studies); the ocular-surface applications have moved closest to human testing, while systemic TB-500 use remains largely experimental. With that context, here is what some of the published work actually reports.

• Annals of the New York Academy of Sciences, 2007 — reviewed the beta-thymosin family and positioned thymosin beta-4 as the main actin-binding peptide involved in cell movement and tissue repair.
• International Immunopharmacology, 2023 — surveyed thymosin beta-4 as a candidate in regenerative-medicine research, summarizing its roles in cell migration, blood-vessel growth, and wound repair.
• Expert Opinion on Biological Therapy, 2018 — reviewed thymosin beta-4's role in the eye, focusing on repair of the ocular surface and cornea, the application that has advanced furthest toward human testing.
• Current Medicinal Chemistry, 2020 — examined thymosin beta-4 and tissue repair after heart injury, describing support for new blood-vessel formation and cell survival in preclinical models.
• Vitamins and Hormones, 2016 — explored thymosin beta-4 in hepatic stellate cells, the liver cells that drive scarring and repair.
• Annals of the New York Academy of Sciences, 2010 — summarized animal studies of thymosin beta-4 as a tissue-repair peptide acting across multiple organs.
• International Immunopharmacology, 2023 — tested thymosin beta-4 in an animal model of bacterial keratitis (corneal infection), reporting effects on inflammation and healing of the eye surface.
• Kidney International, 2016 — investigated thymosin beta-4 in an animal model of kidney (glomerular) disease, examining its effect on injury and scarring in the kidney's filtering units.
• Brain, 2014 — studied thymosin beta-4 in glioblastoma, an aggressive brain tumor, linking the peptide's cell-migration activity to tumor-cell behavior.
• International Immunopharmacology, 2023 — evaluated thymosin beta-4 in an animal model of middle-ear healing, examining repair of the eardrum and middle-ear lining.

What TB-500 is studied for

Cell migration and wound healing. The most fundamental thread: by managing actin, thymosin beta-4 helps repair cells reorganize and crawl toward damaged tissue, the first step of closing a wound. Much of the peptide's other activity flows from this.

Blood-vessel growth (angiogenesis). Injured tissue can only rebuild with a fresh blood supply, and multiple studies describe thymosin beta-4 promoting new vessel formation, a recurring reason it is examined in wound and organ-repair models.

Eye-surface (corneal) repair. Ocular-surface healing is the application that has moved closest to human testing, with preclinical and early clinical work on corneal wounds and infection-related damage of the eye surface.

Organ repair (heart, kidney, liver). Preclinical studies examine thymosin beta-4 in injury to the heart, kidney, and liver, often focusing on reduced scarring and improved tissue recovery in animal models.

Storage & handling

As a lyophilized (freeze-dried) powder, TB-500 reference material is most stable kept cold and dark, refrigerated for short-term storage or frozen for longer holds. Once reconstituted with bacteriostatic water it should be refrigerated at roughly 2-8 °C, kept out of light, and protected from repeated freeze-thaw cycles, which can degrade the peptide. See the reconstitution reference below for the concentration math.

Reconstitution reference

Standard laboratory reconstitution volumes for TB-500, from the VNG Reconstitution Sheet. See the full reconstitution guide for the method and concentration math.