TB-500: Reported Benefits, Side Effects and the State of the Evidence
Also referenced as: Thymosin beta-4 fragment, TB4 (1-4) analogue
TB-500 is the synthetic actin-binding fragment of thymosin beta-4. Here is what published research actually measures, what it does not, and how research-grade vials are characterised.
6 min read · Literature review · Updated 2026
Research-grade TB-500 vials — ≥99% HPLC purity, lot-matched COA on request, from $31.99.
Shop TB-500What TB-500 is
TB-500 is a synthetic peptide corresponding to the actin-binding region of thymosin beta-4, a naturally occurring 43-amino-acid protein involved in cytoskeletal regulation. Research material is supplied as a lyophilised powder and assayed by RP-HPLC with ESI-MS identity confirmation.
The compound is studied mainly as a tool for probing actin dynamics and cell motility. As with BPC-157, the published record is dominated by animal models and cell assays; controlled human efficacy trials of the fragment are not available.
Reported benefits in the published literature
Reported effects follow from the compound's core mechanism — sequestration of G-actin and the downstream effect that has on cell migration and remodelling.
G-actin sequestration
The defining mechanism: TB-500 binds monomeric actin and shifts the polymerisation equilibrium, which is the basis for most downstream observations.
Cell-migration assays
Scratch-wound and transwell assays report increased keratinocyte and endothelial migration rates relative to controls.
Tissue-repair models
Dermal and cardiac injury models in rodents report faster closure and altered remodelling markers.
Inflammatory signalling
Several papers describe reduced inflammatory marker expression in injury models, reported as an associated observation rather than an established pathway.
Reported side effects and safety data gaps
Preclinical reports describe few acute adverse events at the doses studied, but the underlying dataset is thin. There is no controlled human dose-ranging data, no chronic-exposure record, and no regulatory safety review for the fragment.
Because the mechanism directly affects cell migration, reviews consistently list proliferative tissue and long-term remodelling as unresolved questions that current preclinical work cannot answer. Peptide Lounge does not publish dosing or administration guidance, and this material is not for human or veterinary use.
Purity, testing and handling for research use
TB-500 lots are released at ≥99% purity by RP-HPLC with identity confirmed by ESI-MS, and a lot-matched certificate of analysis is available on request. Vials ship lyophilised under argon and are stable at ambient temperature in transit.
Store unreconstituted vials refrigerated and protected from light. Reconstitute with bacteriostatic water immediately before use and treat the solution as short-dated. Researchers determine experimental concentrations from the peer-reviewed literature under their own institutional protocol.
How researchers commonly source the compound
TB-500 is stocked as a 10mg single-compound vial with automatic volume pricing on multi-vial orders. Protocols that compare repair pathways frequently pair it with BPC-157, which is also available as a single co-lyophilised research vial.
Related research vials
TB-500 — frequently asked questions
What are the reported benefits of TB-500?
Published preclinical work reports increased cell migration in scratch-wound and transwell assays, faster closure in dermal and cardiac injury models, and reduced inflammatory marker expression. These are animal and in-vitro findings, not human trial results.
What side effects have been reported for TB-500?
Preclinical reports describe few acute adverse events at studied doses. The substantive concern is missing data: no controlled human dose-ranging, no chronic-exposure record, and open questions about long-term tissue remodelling given the compound's effect on cell migration.
How does TB-500 differ from BPC-157?
They act through different mechanisms. TB-500 sequesters monomeric G-actin and influences cytoskeletal dynamics and cell migration, while BPC-157 is most often described through VEGFR2–Akt–eNOS angiogenic signalling and nitric-oxide system modulation.
Is TB-500 approved for human use?
No. TB-500 is a laboratory reagent supplied for in-vitro and laboratory research only. It is not an approved drug and is not for human or veterinary use.
How is TB-500 tested for purity?
Each lot is assayed by reverse-phase HPLC at ≥99% purity with identity confirmed by ESI-MS. Request the lot-matched certificate of analysis for the batch you received.
Research areas
Tissue repair models
Preclinical dataRodent and in-vitro models have investigated cell migration and remodelling endpoints.
- • Limitation: No controlled human trials for the fragment form.
Cell migration research
In vitro dataIn-vitro work has examined actin sequestration and its relationship to migration assays.
Mechanisms of action (as described in literature)
G-actin sequestration
In vitro dataThe parent peptide is described in literature as binding monomeric actin and influencing polymerisation dynamics.
G-actin binding → cytoskeletal remodelling
Published studies
No peer-reviewed study links are curated for this compound yet. Available information is limited to analytical and preclinical sources. Absence of linked studies should be read as an evidence gap.
Safety signals & data gaps
Reported signals only — safety is not established
Human safety data are unavailable. Reported observations are limited to preclinical models and do not establish safety for human use.
Known data gaps: Human pharmacokinetics, Chronic exposure, Immunogenicity.
For Research Use Only
All products listed are supplied strictly as laboratory reagents for in-vitro research and analytical work conducted by qualified professionals. They are not drugs, foods, cosmetics or medical devices, and must not be administered to humans or animals. No product on this site is approved by the FDA for human use.
Research Use Only: Products are sold strictly for laboratory research and educational purposes only. Not for human consumption, veterinary use, food use, cosmetic use, or therapeutic application. Products are not intended to diagnose, treat, cure, or prevent any disease.