Community protocol
Third-partyTB-500 (Thymosin Beta 4) 10mg
- 01Reconstitution solution
- 1 mL
- 02Dose
- 1 mg
- 03Syringe units
- 10 units
- 04Frequency
- 7x/week
- 05Cycle length
- 90 days
- 06Bacteriostatic water
- 1 mL
- 07Bottle size
- 10 mg
- 08Bottles needed
- 9
TB-500
A synthetic fragment of thymosin beta-4. The parent protein reached phase 2 human trials; the fragment sold as TB-500 has not been trialled in humans.
Overview
TB-500 is a short piece of a larger natural protein called thymosin beta-4, which is one of the most abundant proteins inside cells. That parent protein binds actin, the scaffolding that lets cells change shape and crawl. By influencing actin, it appears to help cells migrate into damaged tissue and encourage new blood vessels to form. Most published work studies the full protein, not the fragment, which is an important distinction when reading the evidence.
Thymosin beta-4 is a 43-amino-acid G-actin sequestering protein. TB-500 corresponds to the LKKTETQ actin-binding domain (residues 17-23), often supplied N-terminally acetylated. The parent protein sequesters G-actin monomers at a 1:1 stoichiometry, buffering the polymerizable actin pool and modulating cytoskeletal dynamics during cell migration. Reported downstream effects in preclinical models include upregulation of laminin-5 and matrix metalloproteinases in corneal and dermal wound models, promotion of endothelial cell migration and tubule formation, activation of Akt in cardiomyocytes after ischaemic injury, and reduction of myofibroblast transdifferentiation. The critical caveat is that most published mechanism data derive from full-length Tβ4; the pharmacokinetics and receptor-independent distribution of the isolated 7-mer fragment are not separately characterized in the peer-reviewed literature.
Research areas
HealingCardiac repairOphthalmicMusculoskeletal
Community-specified data
Community dosage information
Not medical guidance. These third-party figures have not been independently verified, clinically reviewed, or endorsed by DB Peptide. They may be inaccurate or unsafe and should not replace product labelling or advice from a qualified clinician.
Dosing reported in the literature
Every protocol below is reproduced from a published study or approved labelling, with its source named. These are records of what was studied — not recommendations, and not a suggestion that any of them is appropriate for any person.
| Protocol as reported | Source |
|---|---|
| Intraperitoneal Tβ4 in murine dermal wound and cardiac injury models, typically in the microgram-per-animal rangeFull-length protein, rodent model. No validated human equivalent dose exists for the fragment. | Bock-Marquette et al., Nature 2004 |
| 0.1% topical ophthalmic solution, six times daily, in the dry eye programmeRoute and formulation are not comparable to injectable use of the fragment. | RGN-259 phase 2 protocol |
Trial status
Full-length thymosin beta-4 (RGN-259/RGN-352) completed phase 2 trials in dry eye and neurotrophic keratopathy. The TB-500 fragment itself has no registered human trials.
Preclinical
CompletedRodent and porcine models of dermal wound healing, corneal injury, and myocardial infarction, largely using full-length Tβ4.
Phase 2 — dry eye syndrome (RGN-259)
CompletedTopical thymosin beta-4 ophthalmic solution evaluated in dry eye disease. Mixed endpoint results across the trial programme.
Phase 2 — acute myocardial infarction (RGN-352)
TerminatedIntravenous thymosin beta-4 programme was placed on hold and did not report full efficacy outcomes.
Reported safety signals
- No published human safety data exist for the isolated TB-500 fragment.
- Full-length Tβ4 phase 1 studies reported no dose-limiting toxicity, but this does not transfer to the fragment.
- Angiogenic activity raises the same theoretical oncologic concern noted for other pro-angiogenic peptides; it has not been studied directly.
Common questions
Is TB-500 the same as thymosin beta-4?
No. Thymosin beta-4 is the full 43-amino-acid protein. TB-500 is a 7-amino-acid fragment corresponding to its actin-binding domain. Almost all published research uses the full protein, so evidence for one should not be read as evidence for the other.
Primary sources
- 01
Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair
- 02
Thymosin beta4 promotes angiogenesis, wound healing, and hair follicle development
- 03
Mechanism and in vivo effect of thymosin beta 4 on corneal wound healing
- 04
Thymosin β4: A Multi-Functional Regenerative Peptide
Medical disclaimer
This page is for informational and research purposes only. Nothing here constitutes medical advice. The compounds discussed are research chemicals. Consult a qualified clinician before starting any protocol.
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