TL;DR
TB-500 is a synthetic 17-amino acid peptide corresponding to the LKKTETQ active region of Thymosin Beta-4, a major G-actin-sequestering protein found in virtually every mammalian cell type. Research demonstrates the fragment retains most of the biological activity of the parent 43-amino acid peptide, particularly with respect to cell migration and angiogenesis.
Research use only. TB-500 has not received FDA approval for any human therapeutic indication and is sold strictly for in-vitro laboratory research purposes.
What is TB-500?
TB-500 is a synthetic 17-amino acid peptide corresponding to the LKKTETQ active region of Thymosin Beta-4, a major G-actin-sequestering protein found in virtually every mammalian cell type. Research demonstrates the fragment retains most of the biological activity of the parent 43-amino acid peptide, particularly with respect to cell migration and angiogenesis.
Research-grade TB-500 is supplied as a lyophilized powder with batch-specific Certificate of Analysis verification at ≥99% purity by HPLC.
Molecular Properties
| Property | Value |
|---|---|
| Molecular formula | C₈₉H₁₄₃N₂₃O₂₈ |
| Molecular weight | 1,968.25 g/mol |
| Amino acid count | 17 |
| Purity standard | ≥99% (HPLC verified) |
| Lyophilized storage | -20°C, 24–36 months |
| Reconstitution vehicle | Bacteriostatic water (primary), 0.6% acetic acid or saline (alternative) |
Proposed Mechanisms of Action
Published preclinical research has proposed several complementary mechanisms through which TB-500 may exert observed effects in laboratory models. No single mechanism has been fully validated in human contexts.
Actin-sequestering activity
The defining biochemical property: binding monomeric G-actin and altering the G-actin / F-actin ratio with downstream effects on cytoskeletal dynamics, cell shape, and migration.
VEGF and FGF-2 upregulation
Consistent reports across laboratories describe enhanced endothelial tube formation, branching, and capillary density in angiogenesis assays.
Anti-inflammatory signaling
Reduced NF-κB activation and altered cytokine profiles (IL-6, TNF-α) in inflammatory challenge models.
Research Applications
Tissue repair research
Tendon transection, muscle crush, and bone fracture models examining altered histology, biomechanical properties, and functional outcomes.
Angiogenesis and cardiac research
Myocardial infarction models examining infarct size, epicardial progenitor mobilization, and capillary density in ischemic tissue.
Dermal and corneal biology
Excision wound, burn, and corneal epithelium models — the basis for clinical-stage TB4 programs like RGN-259.
Storage and Reconstitution
- Lyophilized at -20°C in original sealed vial; typical shelf life 24–36 months.
- Reconstitution with bacteriostatic water (0.9% benzyl alcohol) is standard. Alternative vehicles include sterile saline or dilute acetic acid depending on experimental requirements.
- Reconstituted solution stored at 2–8°C, used within 7–28 days.
- Avoid repeated freeze-thaw of reconstituted peptide.
- Handling: Follow institutional biosafety protocols; use only in qualified research settings.
Regulatory Considerations
As of early 2026, TB-500 has no investigational human therapeutic indication. The peptide continues to be available for strictly in-vitro research purposes when properly labeled, sold to qualified researchers, and handled under appropriate institutional biosafety protocols. Researchers should consult current FDA guidance and institutional policies before acquiring any research peptide.
Research Gaps
Despite the substantial published literature on TB-500:
- Human pharmacokinetic and pharmacodynamic data remains limited.
- Proposed mechanisms require further validation in human-relevant systems.
- Long-term safety data across species is incomplete.
- Dose-response optimization for specific research applications continues to be an active research question.
- Independent cross-laboratory replication of specific findings is uneven across the literature.
These gaps represent ongoing research opportunities for careful, well-designed preclinical investigation using research-grade material with verified Certificate of Analysis.
Frequently Asked Questions
Is TB-500 approved for human use?
No. TB-500 has no investigational therapeutic indication. It is sold exclusively for in-vitro laboratory research in qualified research settings.
What purity standard should research-grade TB-500 meet?
Quality research-grade material should be ≥99% purity as verified by HPLC with a batch-specific Certificate of Analysis. Aureum Peptides provides COAs with every shipment and maintains a searchable COA portal.
How is TB-500 typically reconstituted for research?
Bacteriostatic water is the most common reconstitution vehicle. Alternative vehicles (sterile saline, dilute acetic acid) may be used depending on specific experimental protocols.
How long is reconstituted TB-500 stable?
Once reconstituted, the peptide is generally stored at 2–8°C and used within 7–28 days depending on specific handling and vehicle. Avoid repeated freeze-thaw cycles.
Where can I verify the Certificate of Analysis for my batch?
Aureum Peptides includes a batch-specific COA with every shipment and maintains an online COA portal accessible using the batch number printed on your vial.
References
- Grant DS et al. Angiogenesis. 1999.
- Sosne G et al. Exp Eye Res. 2007.
- Philp D, Kleinman HK. Ann N Y Acad Sci. 2010.
- Bock-Marquette I et al. Nature. 2004.
- Spurney CF et al. 2010.
(Reference list abbreviated. Full bibliography with DOIs available on request.)
Shop Research-Grade TB-500
Order research-grade TB-500 from Aureum Peptides: TB-500 product page
All peptides ship with batch-specific Certificate of Analysis, ≥99% purity verification, and cold-chain logistics. Same-day dispatch on orders placed before 2:00 PM EST.
Disclaimer: This article summarizes published preclinical research for educational purposes to support qualified research activities. The information herein does not constitute research information, therapeutic claims, or recommendations for human use. TB-500 is not approved by the FDA for any therapeutic indication. Always consult institutional policies and applicable regulations when conducting research with peptides.
Last reviewed: 2026-04-21
Author: Aureum Peptides Scientific Writing Team
Category: Tissue Biology Research
Tags: TB-500, thymosin beta-4, actin sequestering, angiogenesis research
