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TB-500 Clinic

An editorial dark-folio reading of the TB-500 literature — what the thymosin beta-4 fragment is actually studied for, where the human data stop, and how compounded and regulated access really stands.

Section 07 — where to find a cited study

How TB-500 references help you check a healing claim

Slow skin healing can make a repair claim sound useful. These papers let you check what was found, mostly with whole thymosin beta-4 rather than the small part.

Read what happened in plain wordsRead the patient-pharmacy rules

What a number beside a claim lets you check

When you want to check a finding, follow the number beside that claim. The TB-500 papers mostly studied whole thymosin beta-4, so check which substance was given. Some links lead to a study listing or an FDA page. A study listing may say a trial finished without sharing what happened to patients.

A linked paper and a finished-study notice don't give you the same evidence.

Entries marked “reg” lead to FDA's own pharmacy pages. Those sources support the TB-500 pharmacy rules, including rules for medicine made for a named patient. The TB-500 research explanations tell you what the findings mean in everyday words.

  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. 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. ↗
  3. Malinda KM, Sidhu GS, Mani H, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999;113(3):364-368. ↗
  4. Morris DC, Cui Y, Cheung WL, et al. A dose-response study of thymosin β4 for the treatment of acute stroke. J Neurol Sci. 2014;345(1-2):61-67. ↗
  5. Goldstein AL, Hannappel E, Sosne G, Kleinman HK. Thymosin β4: a multi-functional regenerative peptide. Basic properties and clinical applications. Expert Opin Biol Ther. 2012;12(1):37-51. ↗
  6. Ruff D, Crockford D, Girardi G, Zhang Y. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin β4 in healthy volunteers. Ann N Y Acad Sci. 2010;1194:223-229. ↗
  7. RegeneRx / ReGenTree. Assessment of the Safety and Efficacy of RGN-259 Ophthalmic Solutions for Dry Eye (ARISE-3). ClinicalTrials.gov identifier NCT03937882. 2020. ↗
  8. Sosne G, Qiu P, Kurpakus-Wheater M. Thymosin beta 4 suppression of corneal NFkappaB: a potential anti-inflammatory pathway. Exp Eye Res. 2007;84(4):663-669. ↗
  9. Sosne G, et al. RGN-259 (thymosin β4) ophthalmic solution clinical program for dry eye disease (ARISE). ClinicalTrials.gov (topical thymosin β4 dry-eye trials). ↗
  10. Efficacy and Safety Study of Thymosin Beta 4 in Patients With Acute Myocardial Infarction. ClinicalTrials.gov identifier NCT05984134. 2023. ↗
  11. RegeneRx. A Study of the Safety and Efficacy of Injectable Thymosin Beta 4 for Treating Acute Myocardial Infarction (withdrawn). ClinicalTrials.gov identifier NCT01311518. 2011. ↗
  12. Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports Med. 2026. ↗
  13. Qiu P, Wheater MK, Qiu Y, Sosne G. Thymosin beta4 inhibits TNF-alpha-induced NF-kappaB activation, IL-8 expression, and the sensitizing effects by its partners PINCH-1 and ILK. FASEB J. 2011;25(6):1815-1826. ↗
  14. Sosne G, et al. Activation of pro-resolving pathways mediate the therapeutic effects of thymosin beta-4. Front Immunol. 2024;15:1458684. ↗
  15. Kim J, et al. Targeted Deletion of Thymosin Beta 4 in Hepatic Stellate Cells Ameliorates Liver Fibrosis. Cells. 2023;12(12):1658. ↗
  16. Lee Y, et al. Thymosin β4 Regulates Tissue Inflammatory Response in Mouse Nonalcoholic Fatty Liver Disease. J Inflamm Res. 2025;18. ↗
  17. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks (records the September 29, 2023 Category 2 listing for 'Thymosin beta-4, fragment (LKKTETQ), also known as TB-500' and shows it no longer in Category 2 after the nomination was withdrawn; page content current as of April 22, 2026). FDA.gov. ↗
  18. 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). FDA.gov. ↗
  19. 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; bulks-list and PCAC nomination process). FDA.gov. ↗
  20. U.S. Food and Drug Administration. Interim Policy on Compounding Using Bulk Drug Substances Under Section 503A of the FD&C Act (guidance underlying the compounding access pathway and ingredient-eligibility framework). FDA.gov. ↗
  21. Cha HJ, Jeong MJ, Kleinman HK. Role of thymosin beta4 in tumor metastasis and angiogenesis. J Natl Cancer Inst. 2003. ↗
  22. Zhang Y, et al. Thymosin beta 4 is overexpressed in human pancreatic cancer cells and stimulates proinflammatory cytokine secretion and JNK activation. Cancer Biol Ther. 2008. ↗
  23. Ho EN, et al. Doping control analysis of TB-500, a synthetic version of an active region of thymosin β4, in equine urine and plasma by liquid chromatography-mass spectrometry. J Chromatogr A. 2012. ↗
  24. Spurney CF, et al. Evaluation of skeletal and cardiac muscle function after chronic administration of thymosin beta-4 in the dystrophin deficient mouse. PLoS One. 2010. ↗
  25. Delcourt V, et al. TB500/TB1000 and SGF1000: A scientific approach for a better understanding of misbranded and adulterated drugs. Drug Test Anal. 2023. ↗