Research Brief
TB-500: Research Overview
A synthetic peptide based on thymosin β-4, an actin-binding protein studied in preclinical models for tissue repair — not approved for human use, and banned in sport.
Last reviewed: June 2, 2026
For Laboratory Research Use Only
Content on this page describes published research findings. LUMEN BASED does not make therapeutic claims. Consult the primary literature and your institutional review board for protocol design. These products are not for human consumption.
What is TB-500?
TB-500 is a synthetic peptide based on thymosin β-4 (Tβ4), a small, naturally occurring protein. An important clarification up front: the published research is conducted almost entirely on thymosin β-4 itself, not on the "TB-500" trade-named product — so the science below describes Tβ4. Structurally, Tβ4 is a largely unfolded peptide whose defining role is acting as an actin-sequestering protein, which is thought to link the actin cytoskeleton to inflammatory and growth-signaling pathways. [Bubb 2003]
Stated plainly: TB-500 / thymosin β-4 is not approved by the FDA or any major regulatory agency for human use, the evidence is overwhelmingly preclinical, and TB-500 is a banned substance in sport. [Mayfield 2026]
What the research has investigated
Mechanism (actin regulation)
Tβ4's core, well-characterized activity is sequestering actin monomers; reviews propose this connects cytoskeletal dynamics to immune and growth-signaling cascades. [Bubb 2003]
Tissue repair & cardiac regeneration
In mice, Tβ4 has been shown to enhance myocyte survival and cardiac function after coronary-artery ligation, reactivating embryonic and vascular programs — animal-model findings positioned as relevant to regenerative therapy. [Bock-Marquette 2023]
Ocular surface (the furthest along)
Tβ4 is the one thread that reached the clinic: as an eye-drop formulation it progressed from bench discoveries to Phase 3 clinical trials for dry eye and neurotrophic keratopathy. [Sosne 2018]
Immune / sepsis
Reviews of animal work report Tβ4 reduced inflammatory mediators and improved mortality in septic rats, leading authors to suggest human trials are warranted. [Belsky 2018]
Human developmental biology
Immunochemistry and proteomics reviews map Tβ4 (and β10) expression across human fetal and postnatal tissues, underscoring its broad biological roles. [Faa 2024]
The state of the evidence
The honest summary: strong preclinical/animal data plus one clinically-advanced ocular formulation (Tβ4 eye-drops), but the injectable "TB-500" itself has essentially no human efficacy data. A 2026 sports-medicine review notes preclinical promise for angiogenesis and tissue repair but states "human orthopaedic data are lacking," flags critical gaps in dosing, safety, and efficacy, and notes TB-500 remains banned in sport. [Mayfield 2026]
For research use only
LUMEN BASED supplies TB-500 strictly for laboratory and research use. It is not a drug, supplement, or therapeutic product, is not intended for human or veterinary use, and nothing on this page is medical advice or a claim of clinical benefit. Every reference below links to its primary source on PubMed for independent verification.
Verify the batch you're studying
Each TB-500 lot ships with a third-party Certificate of Analysis (HPLC, mass spectrometry, identity confirmation). Pair the batch in your study with the matching COA before publishing or reporting results.
View COA for TB-500 →References
- Bubb MR (2003). Thymosin beta 4 interactions. PubMed
- Bock-Marquette I et al. (2023). Thymosin beta-4 denotes new directions towards developing prosperous anti-aging regenerative therapies. PubMed
- Sosne G (2018). Thymosin beta 4 and the eye: the journey from bench to bedside. PubMed
- Belsky JB et al. (2018). Thymosin beta 4 regulation of actin in sepsis. PubMed
- Faa G et al. (2024). Thymosin β4 and β10 Expression in Human Organs during Development: A Review. PubMed
- Mayfield CK et al. (2026). Injectable Peptide Therapy: A Primer for Orthopaedic and Sports Medicine Physicians. PubMed
For Research Use Only. All LUMEN BASED compounds are strictly for in vitro laboratory research by qualified researchers. Not for human or animal consumption. Not approved by the FDA for therapeutic use.