Peptide Graded

TB-500

Does TB-500 work?

Not properly: animal or lab studies, or small uncontrolled human reports. No human trial of TB-500 exists.

CAnimal and cell studiesNot approvedas of 2026-10-26

There are no published human trials of TB-500 itself. The only TB-500-specific papers are doping-control chemistry studies that identified the peptide in gray-market and veterinary products and detected it in horses. Human trials exist for full-length thymosin beta-4 (a venous-ulcer safety study planned for 72 patients and an 18-patient eye-drop trial), but those tested a different, larger molecule. 3468

No human study of TB-500 has been published. The closest data come from thymosin beta-4 itself. A European randomized, placebo-controlled study in venous leg ulcers was designed to enroll 72 patients. It tested topical thymosin beta-4 for safety and healing. The published report describes the protocol and early enrollment. It does not give final results on whether it works. 3

A phase 3 trial tested thymosin beta-4 eye drops in neurotrophic keratopathy. In this condition the cornea loses sensation and fails to heal. The trial randomized 18 patients. Complete healing at four weeks occurred in 6 of 10 treated patients and 1 of 8 on placebo. The difference did not reach statistical significance for the main measure. These results concern a full-length protein used on the eye. They cannot be transferred to injected TB-500. 4

Evidence checklist

  • Randomised controlled trial No human trial of TB-500 itself
  • Human study over 100 people No human trial of TB-500
  • More than one research group Only doping-chemistry papers
  • Clinical outcomes, not surrogate markers No clinical outcome
  • Human safety data beyond case reports No human exposure data

Read the full TB-500 page

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.