Safe TB-500

References

TB-500 references: every study cited on this site, in full

Primary sources only — peer-reviewed journals, a randomized Phase 1 trial, a withdrawn ClinicalTrials.gov registration, and the FDA pages behind the regulatory status.

Back to the researchRegulatory status

How to read this list

Every quantitative claim on this site maps to a numbered entry below. The literature splits into two molecules — the TB-500 fragment (Ac-LKKTETQ, ~889 Da) and its parent protein thymosin beta-4 (~4963 Da) — and the studies here predominantly used the full-length parent; the page on which each is cited states which molecule was tested. Regulatory entries [16]–[18] are FDA pages verified to load and contain the cited text. This is the full reference list.

  1. Irobi E, Aguda AH, Larsson M, et al. Structural basis of actin sequestration by thymosin-beta4: implications for WH2 proteins. EMBO J. 2004;23(18):3599-3608. ↗
  2. Malinda KM, Sidhu GS, Mani H, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999;113(3):364-368. ↗
  3. Bock-Marquette I, Saxena A, White MD, et al. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472. ↗
  4. Ruff D, Crockford D, Girardi G, Zhang Y. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Ann N Y Acad Sci. 2010;1194:223-229. ↗
  5. Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin beta4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012;12(1):37-51. ↗
  6. Tokura Y, Nakayama Y, Fukada S, et al. Muscle injury-induced thymosin beta4 acts as a chemoattractant for myoblasts. J Biochem. 2011;149(1):43-48. ↗
  7. Xiong Y, Mahmood A, Meng Y, et al. Thymosin beta4 enhances the healing of medial collateral ligament injury in rats. Regul Pept. 2013;184:1-8. ↗
  8. Morris DC, Chopp M, Zhang L, Zhang ZG. A dose-response study of thymosin beta4 for the treatment of acute stroke. J Neurol Sci. 2014;345(1-2):61-67. ↗
  9. Spurney CF, Cha HJ, Sali A, et al. Evaluation of skeletal and cardiac muscle function after chronic administration of thymosin beta-4 in the dystrophin deficient mouse. PLoS One. 2010;5(1):e8976. ↗
  10. Kleinman HK, Sosne G. Thymosin beta4 promotes dermal healing. Animal studies with thymosin beta, a multifunctional tissue repair and regeneration peptide (including porcine ischemia-reperfusion data). Ann N Y Acad Sci. 2010;1194:118-122. ↗
  11. RegeneRx Biopharmaceuticals (sponsor). A Study of the Safety and Efficacy of Injectable Thymosin Beta 4 for Treating Acute Stroke (withdrawn). ClinicalTrials.gov identifier NCT01311518. 2011. ↗
  12. Jo JO, Kang YJ, Ock MS, et al. Thymosin beta4 induces the expression of vascular endothelial growth factor (VEGF) in a hypoxia-inducible factor (HIF)-1alpha-dependent manner. Biochim Biophys Acta. 2010;1803(11):1244-1251. ↗
  13. Kleinman HK, Sosne G, Goldstein AL. Thymosin beta4 and cancer: pro-migratory and pro-angiogenic properties implicated in tumor progression and metastasis (review of the oncologic safety signal). Expert Opin Biol Ther. 2012;12(Suppl 1). ↗
  14. Qiu P, Wheater MK, Qiu Y, Sosne G. Thymosin beta4 promotes matrix metalloproteinase expression during wound repair. J Cell Physiol. 2006;209(2):611-617. ↗
  15. Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports Med. 2026. ↗
  16. Gonzalez-Franquesa A, Stocks B, Borg ML, et al. Discovery of thymosin beta4 as a human exerkine and growth factor. Am J Physiol Cell Physiol. 2021;321(5):C770-C778. ↗
  17. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks (list entry: 'Thymosin beta-4, fragment (LKKTETQ), also known as TB-500'; Category 2, effective September 29, 2023). ↗
  18. U.S. Food and Drug Administration. Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act (Category 1 and Category 2 definitions; 503A/503B framework; nomination and PCAC process). ↗
  19. U.S. Food and Drug Administration. July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee (agenda lists 'TB-500 (free base)' / 'TB-500 acetate', BPC-157, KPV, and MOTs-C as substances being considered for inclusion on the 503A Bulks List; a scheduled discussion, not a decision). ↗