TB-500
Also known as: tb500, tb 500, thymosin beta-4, thymosin beta 4, tβ4
Synthetic fragment of Thymosin Beta-4 researched for wound healing, muscle repair, and anti-inflammation.
Quick Reference
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Overview
Pharmaceutical compound
TB-500 (Ac-LKKTETQ) is a synthetic heptapeptide that corresponds to the N-acetylated active fragment of the endogenous signaling factor thymosin beta-4. It is claimed to increase muscle growth and accelerate wound healing and tissue repair, reduce inflammation, and improve flexibility. There is concern it could be used in sports doping. It gained attention during the 2020s uptick in off-label peptide use. It has not undergone any human trials and high levels of it are associated with tumor development.
Mechanism of Action
Binds G-actin, promotes cell migration and proliferation, upregulates cell surface receptors, modulates inflammatory cytokines.
What is TB-500?
TB-500 is the synthetic version of a short active fragment of thymosin beta-4, a protein found naturally in almost every human cell. Researchers study it for tissue repair, flexibility, and recovery, especially in muscles, tendons, and the heart. Animal and cell studies show it supports cell migration and new blood vessel growth, which are key steps in how tissues rebuild.
How It Works - Simply Explained
Thymosin beta-4, the parent protein of TB-500, is best known for grabbing onto actin, the protein that gives cells their shape and lets them move. By regulating actin, it helps cells migrate to injury sites, a first step in repair. Lab studies also show it calms inflammatory signals and encourages new blood vessel growth, giving researchers three repair levers in one small fragment.
What Studies Have Found
Helped damaged hearts recover in mice
In a landmark 2007 experiment, scientists gave thymosin beta-4 to mice with heart injuries. The protein woke up dormant repair cells on the heart's surface, and treated hearts pumped significantly better than untreated ones. The result made headlines because adult heart tissue was long thought nearly impossible to regenerate.
Smart N, et al., 2007, Nature
Sped up skin wound closure
Researchers testing thymosin beta-4 on skin wounds found treated wounds closed faster and with better-quality new tissue. Cell-migration studies showed why: the protein helps repair cells travel to the damage site more efficiently. This wound-healing work is among the earliest published findings on the protein.
Malinda KM, et al., 1999, Journal of Investigative Dermatology
Promoted healing of the eye's surface
In corneal wound studies, thymosin beta-4 helped the eye's outer layer repair itself more quickly while calming inflammation. Eye researchers were excited because the cornea must heal clearly to preserve vision, and the protein supported clean, organized repair.
Sosne G, et al., 2002, Experimental Eye Research
Stimulated hair follicle growth in mice
When applied in lab studies, thymosin beta-4 pushed resting hair follicles into their active growth phase sooner, producing faster and fuller regrowth in mice. Follow-up work pointed to the protein's effect on follicle stem cells. Hair biology remains an active area of thymosin research.
Philp D, et al., 2004, FASEB Journal
Revealed a multi-pathway repair mechanism
Reviewing decades of work, researchers mapped how thymosin beta-4 regulates actin for cell movement, dampens inflammatory signaling, and supports vessel growth. Understanding these three levers helps explain why one small protein shows effects in heart, skin, eye, and hair studies alike.
Goldstein AL, et al., 2012, Annals of the New York Academy of Sciences
Last updated 2026-10-06. New findings are added as published research appears.
Frequently Asked Questions
What is TB-500?
TB-500 is a synthetic peptide version of the active region of thymosin beta-4, a protein found naturally in nearly every human and animal cell. It is sold strictly for laboratory research, mainly in tissue-repair studies.
What is the difference between TB-500 and thymosin beta-4?
Thymosin beta-4 is the full natural protein at 43 amino acids long. TB-500 is a shorter synthetic fragment containing the protein's key active region. Researchers use TB-500 because the small fragment is easier to synthesize and study.
What have studies found about TB-500?
Published research on thymosin beta-4 and its fragments reports improved heart repair in mice, faster skin wound closure, corneal healing, hair follicle stimulation, and reduced inflammatory signaling. Most findings come from animal and cell studies.
Why do researchers study TB-500 together with BPC-157?
The two appear to work through complementary mechanisms: BPC-157 is associated with blood vessel growth and gut-tissue protection, while TB-500 is tied to cell migration and actin regulation. Studying them side by side lets researchers compare repair pathways.
Has TB-500 been tested in humans?
The parent protein thymosin beta-4 has entered early human trials for certain conditions, but TB-500 itself remains primarily a preclinical research compound with most data from animal and cell models.
Is TB-500 legal for research?
It is sold legally as a research chemical for laboratory use only, not for human consumption. It is not an FDA-approved drug, and regulations vary by country, so researchers should check local rules.
How is TB-500 stored?
Suppliers typically ship it as a freeze-dried powder and recommend cold, dry storage to preserve stability. Exact storage guidance comes from the supplier's certificate of analysis and product documentation.
FDA News About This Compound
What Researchers Are Saying
Community Reports - Not Medical Advice
The following is aggregated from public forums, Reddit, and research communities. These are anecdotal reports from researchers only - not verified clinical data and not a recommendation of any kind.
TB-500 (also known as tb500, tb 500) is studied within the tissue repair and recovery research community. Synthetic fragment of Thymosin Beta-4 researched for wound healing, muscle repair, and anti-inflammation.
Last updated October 28, 2026
Research status: active. TB-500 appears across tissue repair and recovery research forums and academic literature. Researchers note this compound falls in the tissue repair category.
Last updated October 28, 2026
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