How it works
Binds G-actin and promotes actin polymerisation, which drives cell migration into damaged tissue. It also stimulates endothelial cell differentiation and new capillary growth, and downregulates inflammatory cytokines.
Structure: 7 amino acids (actin-binding domain of Tβ4)
Reported benefits
- Improved cell migration and wound closure in animal studies
- Reported flexibility gains and reduced muscle spasm
- Systemic action rather than site-specific, unlike BPC-157
Practical considerations
- Frequently stacked with BPC-157 in anecdotal recovery protocols
- Human data is limited to Tβ4 trials in dry-eye and cardiac injury
- Prohibited by WADA at all times
Side effects and risks
- Fatigue or head-rush after dosing
- Injection-site reaction
- Theoretical tumour-growth concern given angiogenic activity
TB-500 dosing overview
Loading phase of 2–5 mg twice weekly for 4–6 weeks, then a lower maintenance dose
| Context | Amount | Frequency | Route |
|---|---|---|---|
| Loading phase | 2–5 mg | 2× weekly, 4–6 weeks | Subcutaneous or intramuscular |
| Maintenance | 2 mg | Every 1–2 weeks | Subcutaneous |
This describes doses reported in published literature and community protocols. It is not a recommendation, and it is not a substitute for clinical supervision.
TB-500 FAQ
Is TB-500 the same as thymosin beta-4?
No. TB-500 is a short synthetic fragment containing the actin-binding region of the full Tβ4 protein. Most published biology describes full-length Tβ4, not the fragment sold as TB-500.
Why is TB-500 dosed twice weekly?
Plasma half-life is only a few hours, but the downstream effects on cell migration and capillary growth persist far longer, so protocols space doses out rather than dosing daily.
Is TB-500 banned in sport?
Yes. WADA lists TB-500 among prohibited growth factors at all times, in and out of competition.
Is it often combined with BPC-157?
Community protocols frequently pair the two on the theory that the mechanisms are complementary — angiogenesis plus cell migration. No controlled human study has tested the combination.
Research references
- Goldstein et al., 2012 — Thymosin β4 in tissue repair
- Malinda et al., 1999 — Tβ4 accelerates wound healing