TB500 (Thymosin Beta-4)

What Is TB500?

TB500 is a synthetic analogue of Thymosin Beta-4 (Tβ4), a naturally occurring 43-amino-acid protein found in virtually all nucleated cells. The active fragment (amino acids 17–23, Ac-LKKTETQ) retains the full biological activity of the parent molecule at lower molecular weight. TB500 plays a central role in actin cytoskeletal dynamics — the molecular machinery behind cell movement, wound closure, and tissue repair.

Key Mechanisms

• G-actin sequestration — binds monomeric actin, enabling rapid cell movement during repair
• Angiogenesis — promotes endothelial tube formation and MMP-2 expression for new blood vessel growth
• ILK / Akt activation — pro-survival signalling in cardiomyocytes and muscle cells under stress
• Anti-inflammatory — downregulates TNF-α and IL-6; reduces neutrophil infiltration
• Epicardial progenitor activation — mobilises cardiac stem cells post-myocardial injury

Research Applications

• Systemic wound healing acceleration (diabetic wound models)
• Cardiac repair post-MI (epicardial progenitor cell mobilisation)
• Corneal epithelial healing (Phase II clinical data)
• CNS remyelination and stroke recovery models
• Muscle repair and anti-fibrotic effects

Stacking

Most commonly combined with BPC-157 for comprehensive tissue repair — the most studied peptide stack in preclinical research. Can be combined with GHK-Cu for collagen matrix rebuilding.

Key References

1. Smart N et al. “Thymosin beta4 induces adult epicardial progenitor mobilization.” Nature, 2007;445:177–182.
2. Malinda KM et al. “Thymosin beta4 stimulates directional migration of endothelial cells.” FASEB J, 1997;11:474–481.
3. Goldstein AL et al. “Thymosin beta4: a multi-functional regenerative peptide.” Expert Opin Biol Ther, 2012;12:37–51.