TB-500 is a synthetic fragment of thymosin beta-4, a natural repair-related peptide. Eye-drop forms of Tβ4 have been in human trials; we found no human trials of TB-500. Not authorized in Canada.
How strong is the human evidence?
- Cell & animal
- Small human studies
- Some randomized trials
- Large randomized trials
What is TB-500 and Thymosin Beta-4?
Thymosin beta-4 (Tβ4) is a natural peptide involved in cell movement and tissue repair.
TB-500 is a synthetic version of an active region of Tβ4. Detection methods for it in racehorses were published in 2012.
Is TB-500 and Thymosin Beta-4 legal in Canada?
Not authorized. Health Canada lists TB-500 among unauthorized peptides found for sale and among seized injectables.
What the research shows
- Tβ4 eye drops (RGN-259): a small Phase 2 randomized trial in severe dry eye reported improved signs and symptoms (Sosne et al., Cornea 2015).
- A Phase I study of recombinant Tβ4 in healthy volunteers was published in 2021.
What it doesn't show
- We found no published human trials of TB-500 for injuries, muscle or recovery.
- Eye-drop results for Tβ4 say nothing about injected TB-500.
Common questions
Is TB-500 the same as thymosin beta-4?
No. TB-500 is a synthetic fragment based on part of Tβ4.
Is TB-500 legal in Canada?
No. Health Canada lists it among unauthorized injectable peptides.
BPC-157 vs TB-500?
Both are unauthorized in Canada, both are banned in sport, and neither has convincing human evidence for healing injuries.
Sources
- Health Canada — Peptides: Overview
- Health Canada advisory RA-81874 (Apr 9, 2026): Think twice before injecting peptides bought online
- Ho EN et al. Doping control analysis of TB-500 in equine urine and plasma. J Chromatogr A 2012
- Sosne G et al. Tβ4 improves severe dry eye in a phase 2 randomized trial. Cornea 2015
- Wang X et al. First-in-human phase I study of recombinant Tβ4. J Cell Mol Med 2021
- World Anti-Doping Agency — Prohibited List
Related
BPC-157The most-searched "healing peptide". Animal studies are plentiful, but a 2026 systematic review found only 3 tiny human…Not authorized in Canada
Thymosin Alpha-1An immune-modulating peptide (thymalfasin) studied in infections, cancer and COVID-19. Meta-analyses disagree on…Not authorized in Canada (approved elsewhere)