Research question

What is the half-life of TB-500?

TB-500‘s published plasma half-life in rodent subcutaneous-administration models is approximately 1.5-3 hours. Like BPC-157, the tissue-level effects observed across multi-day dosing protocols extend well past what the plasma half-life alone would predict, supported by the compound’s binding-target pharmacology.

What the research literature says

TB-500 is the synthetic acetylated fragment of thymosin β4 used across research protocols where the full-length thymosin β4 is impractical or unavailable. The plasma pharmacokinetic profile reflects the small size of the compound (17 amino acids) and the absence of engineered long-acting modifications. Subcutaneous administration in rodent models shows peak plasma concentrations within an hour and clearance within several hours.

The functional pharmacology operates on a longer time scale through two distinct mechanisms. The first is G-actin sequestration via a defined actin-binding motif on the peptide — once internalised by target cells, the peptide engages the cytoskeletal-remodelling machinery on the time scale of cellular turnover rather than plasma clearance (PMID 11579089). The second is engagement of integrin-linked kinase and downstream PI3K-Akt signalling on cardiac and endothelial cells, which produces transcriptional responses that persist beyond the receptor-engagement window (PMID 15565145).

Published dosing protocols for TB-500 in preclinical research typically use subcutaneous administration once to twice weekly, with cumulative effects observed across 4-8 week protocols (PMID 27450738, PMID 32945357). The dosing-interval choice is driven by the functional time scale of the cytoskeletal and cell-migration responses rather than by direct extension of the plasma half-life.

Why this matters in research context

The plasma-vs-tissue half-life distinction is more pronounced for TB-500 than for many peptide research compounds. Researchers running plasma-based pharmacokinetic assays will see rapid clearance signals; researchers measuring tissue-level repair or migration responses will see effects accumulating across a much longer window. Protocol design typically anchors the dosing interval to the functional response time scale rather than to the plasma-clearance time scale.

Related compounds

TB-500 10mg — the compound covered by this answer
Wolverine Stack (BPC-157 + TB-500 blend) — combined-research formulation

References

Yarmola EG et al. Formation and implications of a ternary complex of profilin, thymosin beta 4, and actin. J Biol Chem 2001;276(49):46094-46101. [PMID 11579089]
Bock-Marquette I et al. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature 2004;432(7016):466-472. [PMID 15565145]
Kleinman HK et al. Thymosin β4 Promotes Dermal Healing. Vitam Horm 2016;102:251-275. [PMID 27450738]
Lv S et al. Thymosin-β 4 induces angiogenesis in critical limb ischemia mice via regulating Notch/NF-κB pathway. Int J Mol Med 2020;46(4):1347-1358. [PMID 32945357]

Research-questions pages describe research-context use of peptide-research terminology. They do not constitute medical, veterinary, or clinical advice. TB-500 is sold strictly as a research-grade reagent for laboratory and bench research applications.