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TB-500 (Thymosin Beta-4)

Tissue Repair & Recovery · ['TB-500', 'Thymosin Beta-4', 'TB4', 'Tβ4', 'Fragment 17-23 (active region)']

TB-500 is a synthetic peptide related to the actin-binding protein Thymosin Beta-4, studied preclinically for roles in cell migration, angiogenesis, and tissue repair.

🔬 Research use only — not for human or veterinary use. K4 Elite does not provide dosing instructions.
Molecular Formula
C212H350N56O78S
Molecular Weight
4963 g/mol
PubChem
CID 45382195 ↗
Research Level
Well Researched
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TB-500 (Thymosin Beta-4) chemical structure

Thymosin Beta-4 (Tβ4) is a naturally occurring 43-amino-acid peptide and one of the most abundant members of the beta-thymosin family. It is a major intracellular actin-sequestering protein and has been studied for decades for its role in cell motility and cytoskeletal regulation. "TB-500" is a name commonly used in the research-chemical market to refer to a synthetic peptide associated with the biologically active region of Tβ4.

Important note: full-length Thymosin Beta-4 (PubChem CID 45382195, C212H350N56O78S) is the parent molecule, while material marketed as "TB-500" is often described as a shorter fragment. The two are related but not always chemically identical, and the reference data shown here correspond to full-length Thymosin Beta-4.

Research on Tβ4 spans wound healing, corneal repair, cardiac injury, and hair-follicle biology, with much of the work performed in animal and cell-culture models. It is not an approved drug for the indications discussed here.

The best-characterized biochemical activity of Thymosin Beta-4 is sequestration of monomeric G-actin, which regulates the actin cytoskeleton and thereby influences cell migration, a key step in tissue repair. This actin-binding activity is attributed largely to a short central sequence within the peptide.

Preclinical studies additionally describe effects on angiogenesis, upregulation of endothelial cell migration, modulation of inflammatory signaling, and promotion of progenitor-cell recruitment in models of cardiac and dermal injury. These are proposed mechanisms drawn from animal and in vitro research and have not been confirmed as clinical effects in humans.

  • Dermal wound healing and keratinocyte/endothelial cell migration in animal and cell models [1]
  • Corneal epithelial repair, including clinical study of a Tβ4-based ophthalmic formulation for dry eye [2]
  • Cardiac repair and cardiomyocyte survival following experimental myocardial injury [3]
  • Angiogenesis and progenitor-cell recruitment in vascular tissue models [1]
  • Actin-cytoskeleton regulation and cell-motility biochemistry [4]
📋 How published studies were conducted — a research reference summarizing study designs from the literature. This is not usage, dosing, or administration guidance. K4 Elite does not provide dosing instructions; determining any research protocol is the sole responsibility of the qualified researcher.

Bock-Marquette and colleagues reported in a mouse model that Thymosin Beta-4 treatment following experimental myocardial infarction was associated with improved cardiomyocyte survival and cardiac function; measured outcomes included ejection fraction and infarct scar area [3].

Malinda and colleagues studied Tβ4 in dermal wound-healing models, reporting accelerated wound closure and increased angiogenesis in rat full-thickness wounds, with wound-area measurement and vessel counts as endpoints [1].

A Tβ4-based ophthalmic solution (RGN-259) has been evaluated in human clinical trials for dry-eye disease and neurotrophic keratopathy, examining corneal staining and epithelial healing as outcomes; results have been reported in the ophthalmology literature [2].

Combinations examined in the research literature. Descriptive only — not a recommendation to combine compounds.

BPC-157Compatible
Commonly discussed alongside TB-500 in tissue-repair research; no controlled human co-administration data exist.
Actin (G-actin)Synergistic
Direct actin sequestration is the primary characterized biochemical activity of Thymosin Beta-4.
VEGF / angiogenic signalingSynergistic
Preclinical studies report enhanced endothelial migration and angiogenesis.
Inflammatory cytokinesNeutral
Some models report modulation of inflammatory signaling; findings are context-dependent and preclinical.
  1. Malinda KM et al., FASEB J 1999 (Tβ4 wound healing)
  2. Sosne G et al., Expert Opin Biol Ther 2015 (RGN-259 / Tβ4 cornea)
  3. Bock-Marquette I et al., Nature 2004 (Tβ4 cardiac repair)
  4. Goldstein AL et al., Ann N Y Acad Sci 2012 (Tβ4 review)
  5. PubChem: Thymosin beta-4 (CID 45382195)
Is TB-500 the same as Thymosin Beta-4?
They are closely related but not always identical. Thymosin Beta-4 is the full 43-amino-acid natural peptide; 'TB-500' is a research-market name often referring to a synthetic fragment associated with its active region.
What has Thymosin Beta-4 been studied for?
Preclinical and some clinical research has examined wound healing, corneal repair, cardiac injury, angiogenesis, and its fundamental role in regulating the actin cytoskeleton.
Has it been tested in humans?
A Tβ4-based ophthalmic solution has been studied in human clinical trials for eye-surface conditions. Broader systemic uses remain preclinical, and TB-500 as sold is not an approved drug.
Is TB-500 FDA approved?
No. TB-500 is not approved by the FDA for any use.
Is this product intended for human use?
No. This material is supplied strictly for laboratory and research use only. It is not a drug or supplement and is not intended for human or veterinary consumption or administration.
Disclaimer: This profile summarizes published preclinical and laboratory research for reference only. It is not medical advice and makes no claim of safety or efficacy in humans. Determining any research protocol is the sole responsibility of the qualified researcher. Products are sold strictly for in-vitro research and have not been evaluated by the FDA.