TB-500 (Thymosin Beta-4 Fragment)
Also Known AsThymosin Beta-4 · Tβ4 · TB4 · Timbetasin
Thymosin Beta-4 is a 43-amino-acid peptide naturally produced by the thymus gland. TB-500 is a synthetic version of the active region of thymosin beta-4. Originally isolated in the 1960s by Allan Goldstein at the National Institutes of Health as part of thymus-derived peptide research.
Ac-SDKP (active fragment)How TB-500 Works
Actin Sequestration & Cell Migration
TB-500 binds G-actin monomers, promoting actin polymerization and cell motility. By regulating the actin cytoskeleton, it facilitates cell migration to injury sites, which is the primary mechanism underlying its tissue repair effects.
Anti-Inflammatory Signaling
Downregulates pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6 while promoting anti-inflammatory mediators. The N-terminal tetrapeptide Ac-SDKP specifically inhibits NF-κB signaling in activated monocytes and macrophages.
Angiogenesis
Promotes new blood vessel formation through upregulation of VEGF and HIF-1α. In cardiac ischemia models, this neovascularization is a key mechanism for tissue salvage and functional recovery.
Epigenetic Regulation
Recent research identifies TB-500 as a modulator of chromatin remodeling through its interaction with SIRT1 and histone deacetylases, influencing gene expression patterns related to wound healing and fibrosis.
Published Research
Cardiac Repair
ModeratePreclinical studies in mouse and rat myocardial infarction models demonstrate that thymosin beta-4 promotes cardiomyocyte survival, reduces scar size, and improves ejection fraction. Mechanisms include activation of Akt (cell survival) and stimulation of epicardium-derived progenitor cells. Phase I clinical trial data (RegeneRx) showed safety in acute MI patients.
Dermal Wound Healing
StrongExtensive preclinical evidence shows accelerated wound closure, increased angiogenesis, and reduced scarring in full-thickness skin wound models. The topical formulation (RGN-259) has completed Phase 3 trials for neurotrophic keratopathy (corneal wound healing) with positive results.
Musculoskeletal Repair
ModeratePreclinical data demonstrates improved tendon, ligament, and muscle repair in injury models. Enhanced collagen deposition, reduced inflammatory infiltrate, and improved biomechanical strength have been consistently reported. Often studied in combination with BPC-157.
Neuroprotection
EmergingEmerging evidence in traumatic brain injury, spinal cord injury, and multiple sclerosis models shows reduced neuroinflammation, enhanced oligodendrocyte differentiation, and improved functional outcomes. Proposed mechanisms include anti-inflammatory effects and promotion of neural progenitor cell migration.
Hair Follicle Regeneration
PreclinicalPreclinical studies demonstrate stimulation of hair follicle stem cells and promotion of hair growth in mouse models. Thymosin beta-4 activates hair follicle progenitor cells and promotes transition from telogen (resting) to anagen (growth) phase.
Safety Profile
Thymosin beta-4 has demonstrated favorable safety profiles in multiple Phase I/II clinical trials (cardiac, corneal, and dermal applications). No dose-limiting toxicities reported in human studies to date. As an endogenous peptide present in all nucleated cells, it has a wide therapeutic index in preclinical models.
Handling & Storage
Reconstitute with bacteriostatic water. TB-500 is highly soluble and stable in aqueous solution. Store reconstituted solution at 2-8°C and use within 30 days. Lyophilized powder stable at -20°C for 24+ months.
Peer-Reviewed Literature
- 1
Thymosin β4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair
Bock-Marquette I, Saxena A, White MD, et al.
- 2
The actin binding site on thymosin β4 promotes angiogenesis
Philp D, Huff T, Gho YS, et al.
- 3
Biological activities of thymosin β4 defined by active sites in short peptide sequences
Sosne G, Qiu P, Goldstein AL, Wheater M.
- 4
Thymosin β4 is an essential paracrine factor of embryonic endothelial progenitor cell-mediated cardioprotection
Hinkel R, El-Aouni C, Olson T, et al.
- 5
Thymosin β4 induces adult epicardial progenitor mobilization and neovascularization
Smart N, Risebro CA, Melville AAD, et al.
TB-500 FAQ
What is TB-500?
TB-500 is a synthetic peptide corresponding to the active region of thymosin beta-4, a 43-amino-acid protein naturally produced by the thymus gland and present in virtually all human cells. It has been extensively studied for tissue repair, anti-inflammatory effects, and cell migration properties.
How is TB-500 different from Thymosin Beta-4?
TB-500 is the synthetic research-grade form of the active region of naturally occurring thymosin beta-4. The full thymosin beta-4 protein and TB-500 share the same active sequences responsible for biological activity. TB-500 is manufactured to 99%+ purity for research applications.
What is the difference between TB-500 and BPC-157?
TB-500 (thymosin beta-4) primarily works through actin sequestration and cell migration, promoting repair via cellular mobilization. BPC-157 primarily works through nitric oxide modulation and growth factor upregulation. They act through different but complementary pathways, which is why they are frequently studied together in preclinical injury models.
Has TB-500 been studied in human clinical trials?
Yes. RegeneRx Biopharmaceuticals has conducted multiple human clinical trials with thymosin beta-4, including Phase I trials for cardiac repair post-MI and Phase 3 trials for corneal wound healing (RGN-259 for neurotrophic keratopathy). Safety has been demonstrated across these human studies.
TB-500 Products
All compounds 99%+ purity, verified by Janoshik Analytical. GMP-manufactured lyophilized powder.
TB-500
10mgYour body's built-in repair signal — speeds muscle recovery, heals stubborn injuries, and reduces chronic inflammation and pain.
- Dramatically speeds muscle and tissue recovery
- Reduces inflammation and chronic pain
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Disclaimer: This monograph is provided for educational and research purposes only. G26x Peptides products are sold exclusively as research chemicals. They are not intended for human consumption, therapeutic use, or as dietary supplements. All research should be conducted in compliance with applicable laws and institutional review board protocols. Information presented here is sourced from published peer-reviewed literature and does not constitute medical advice.