TB-500
Synthetic fragment of thymosin beta-4
- Class
- Repair peptide
- Half-life
- Hours-days
- Route
- Subcutaneous (SubQ)
- Cadence
- Weekly
- Evidence
- Animal data primarily
Overview
TB-500 is the cousin peptide to BPC-157 — both are popular in the recovery community, both have mostly animal evidence. The name is misleading: "TB-500" usually means a short active fragment of thymosin beta-4 (a natural protein involved in cell movement and wound healing), not the full-length protein itself.
What it does, in theory: helps cells move where they need to go to fix damaged tissue. The full-length parent protein has been in clinical trials for diabetic foot ulcers and pressure injuries — those trials are still pre-approval. The fragment that gets sold as "TB-500" hasn't been formally tested in humans at all.
Most of the recovery-community usage is for tendon and ligament injuries — extrapolated from animal studies on the full protein and a few veterinary reports in horses. WADA-prohibited, so a no-go for any tested athlete.
Safety considerations
A few of the safety signals worth knowing — the full list, with dosing context and what to monitor, is inside AIx Core.
- No approved human use of either the fragment or the full protein. Safety in humans is essentially uncharacterised at the dose levels used in research.
- WADA-prohibited — if you compete in a tested sport, this can end your career.
- Theoretical concern: angiogenic effects could in principle accelerate hidden tumours. Same concern as BPC-157, same logic — probably fine for healthy people, problematic if you have cancer history.
+ 2 more safety notes inside AIx Core →
Commonly monitored
Markers and signals people track when researching TB-500.
- Subjective injury markers — pain, range of motion, daily function
- Imaging if you have a specific structural injury you're tracking
- Injection-site reactions (most common practical issue)
Frequently asked questions
What is TB-500?
Synthetic fragment of thymosin beta-4. TB-500 is the cousin peptide to BPC-157 — both are popular in the recovery community, both have mostly animal evidence. The name is misleading: "TB-500" usually means a short active fragment of thymosin beta-4 (a natural protein involved in cell movement and wound healing), not the full-length protein itself.
How is TB-500 administered?
Subcutaneous (SubQ), typically weekly.
What is the half-life of TB-500?
Hours-days — Tissue effects last way longer than blood levels would suggest.
Is TB-500 approved for human use?
TB-500 is investigational — not approved by the FDA, EMA, or MHRA for human use at the time of writing.
What does the evidence show for TB-500?
Evidence tier: Animal data primarily. Goldstein 2012 (the most-cited TB-4 review) summarises the full-length protein's biology — useful background, but most of it doesn't transfer cleanly to the active fragment that's actually sold.
What is commonly monitored when researching TB-500?
Commonly tracked markers + signals: Subjective injury markers — pain, range of motion, daily function, Imaging if you have a specific structural injury you're tracking, Injection-site reactions (most common practical issue).
Related compounds
Open this in AIx Core for the full picture
Mechanism breakdown, receptor pathway diagram, full safety list, monitored items, source citations, and one-tap add-to-protocol. Free with any account.