Peptide Graded

TB-500

Is TB-500 safe?

No human exposure data

CAnimal and cell studiesNot approvedas of 2026-10-26

There are no safety data for TB-500 in humans. The FDA's compounding review notes the absence of human exposure data. The 2026 advisory committee vote was split. It was reported as 8 to 6 with one abstention. The FDA's own scientists did not support the easing. Full-length thymosin beta-4 was well tolerated in the small eye and wound trials. But no one has studied the fragment. 2710

TB-500 is prohibited in sport. The World Anti-Doping Agency and horse racing authorities ban it. Methods exist to detect it in plasma and urine. 89

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More on TB-500

Citations

  1. Goldstein 2012, Expert Opin Biol Ther: Thymosin beta4, a multifunctional regenerative peptide doi.org
  2. McDermott Will & Emery 2026: PCAC backs majority of peptides in two-day public meeting mcdermottlaw.com
  3. Guarnera 2007, Ann N Y Acad Sci: Thymosin beta-4 and venous ulcers, a European randomized study pubmed.ncbi.nlm.nih.gov
  4. Sosne 2022, Int J Mol Sci: RGN-259 ophthalmic solution in neurotrophic keratopathy, phase 3 pubmed.ncbi.nlm.nih.gov
  5. Goldstein 2007, Ann N Y Acad Sci: Thymosin beta4 overview doi.org
  6. Esposito 2012, Drug Test Anal: Synthesis and characterization of the 17-23 fragment identified in TB-500 pubmed.ncbi.nlm.nih.gov
  7. FDA: Certain bulk drug substances for use in compounding may present significant safety risks fda.gov
  8. Ho 2012, J Chromatogr A: Doping control analysis of TB-500 in equine urine and plasma pubmed.ncbi.nlm.nih.gov
  9. 2025, Drug Test Anal: Equine doping controls of thymosin beta 4, a population study pubmed.ncbi.nlm.nih.gov
  10. STAT 2026: FDA peptide compounding panel backs epitalon, rejects emideltide statnews.com

Reference information only, not medical advice. Drawn from the TB-500 article, fact-checked against the cited sources. No dosing anywhere on this site.