Summary

TB-500 is a synthetic peptide based on a key active region of thymosin beta-4, a naturally occurring protein involved in wound healing and tissue repair. Research suggests it may promote cell migration, reduce inflammation, and support recovery from musculoskeletal injury — though the human evidence base remains limited, with most findings coming from animal and in vitro studies.

Mechanism

TB-500 is a synthetic fragment of thymosin beta-4 (Tβ4) that retains the actin-binding LKKTET motif. By sequestering G-actin, Tβ4 regulates actin polymerisation, which is essential for cell motility and migration — key processes in wound healing. Tβ4 also promotes angiogenesis (new blood vessel formation), modulates inflammatory cytokine signalling, and supports cell survival through integrin-linked kinase (ILK) activation. These combined mechanisms underpin its studied effects on tissue repair and inflammation reduction. (Philp et al., 2003; Bock-Marquette et al., 2004)

Evidence base

The evidence base for TB-500/thymosin beta-4 is primarily preclinical. Animal models have demonstrated accelerated wound healing (Philp et al., 2003), improved cardiac repair after experimental myocardial infarction (Bock-Marquette et al., 2004), and anti-inflammatory effects. A limited number of human studies exist, including a phase 2 trial of Tβ4 eye drops for dry eye disease (Sosne et al., 2015). No large-scale human clinical trials of TB-500 for musculoskeletal applications have been published. Evidence should be considered preliminary and based largely on animal models.

Protocols

Commonly discussed in research contexts (not validated by human clinical trials): Typical dose 2–5 mg per week via subcutaneous injection, often split into two doses. A loading phase of 4–6 weeks at 5 mg/week may be followed by a maintenance phase at 2 mg/week. Cycle length typically 4–8 weeks with at least 4 weeks off. Commonly stacked with BPC-157 (250–500 mcg/day) for combined tissue-repair protocols.

TB-500 is not a licensed medicine in the UK and is not a controlled substance. It is legal to purchase and possess for research purposes. TB-500 has not been approved by the MHRA for human therapeutic use. Products sold by UK vendors are marketed as research chemicals, not for human consumption.

Vendor notes

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References

  1. Philp D, Huff T, Gho YS, et al. The actin binding site on thymosin beta4 promotes angiogenesis. Journal of Biological Chemistry. 2003;278(47):46930-46938. doi:10.1074/jbc.M307012200
  2. Bock-Marquette I, Saxena A, White MD, Dimaio JM, Srivastava D. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472. doi:10.1038/nature03087
  3. Sosne G, Qiu P, Goldstein AL, Wheater M. Biological activities of thymosin beta4 defined by active sites in short peptide sequences. Annals of the New York Academy of Sciences. 2010;1194:14-26. doi:10.1111/j.1749-6632.2010.05446.x
  4. Sosne G, Chan CC, Thompson P, et al. Thymosin beta4 promotes corneal wound healing and decreases inflammation in rabbits following alkali injury. Investigative Ophthalmology & Visual Science. 2014;55(10):6554. doi:10.1167/iovs.14-14998
  5. Crockford D, Turjman N, Allan C, Angel J. Thymosin beta4: structure, function, and clinical applications. Annals of the New York Academy of Sciences. 2010;1194:179-185. doi:10.1111/j.1749-6632.2010.05454.x