Index of Peptides Lab UK reference content on TB-500 (the synthetic Thymosin Beta-4 fragment) — covering actin-binding mechanism, in-vitro and in-vivo tissue-research applications research, analytical quality standards, and combination-protocol references with BPC-157.
What is TB-500?
TB-500 is a synthetic fragment of the naturally occurring 43-amino-acid protein Thymosin Beta-4 (Tβ4). Most “TB-500” research material in supply corresponds to the active actin-binding domain of Tβ4 (residues 17–23, sequence Leu-Lys-Lys-Thr-Glu-Thr-Gln, sometimes referred to as the LKKTETQ fragment) or the full Tβ4 sequence — verify with each supplier’s COA. Peptides Lab UK supplies the synthetic full-length Tβ4 sequence at >99% HPLC purity.
Thymosin Beta-4 is the most abundant intracellular actin-sequestering peptide in mammalian cells. The molecule is examined in laboratory research for cell-migration, dermal-wound, cardiac, and corneal-tissue research models.
Mechanism — what TB-500 is studied for
- Actin sequestration — Tβ4 binds monomeric G-actin via a thymosin-domain α-helix, modulating the G-actin / F-actin equilibrium and downstream cell-cytoskeletal dynamics.
- Cell migration — research models examine Tβ4 effects on dermal fibroblast and endothelial-cell migration.
- Angiogenic signalling — laboratory endothelial-cell research has characterised effects on VEGF and VE-cadherin pathway interactions.
- Corneal wound research — Tβ4 has been examined in corneal epithelial-cell migration models.
- Cardiac progenitor research — Tβ4 effects on epicardial progenitor cells have been examined in laboratory cardiac tissue models.
TB-500 vs BPC-157 — research mechanism comparison
| Dimension | TB-500 | BPC-157 |
|---|---|---|
| Molecular size | ~5 kDa (full Tβ4) / 7 aa (LKKTETQ) | 15 aa (~1.4 kDa) |
| Primary research mechanism | Actin-binding, cell migration | VEGFR2 / NO-pathway / cytoprotection |
| Origin | Synthetic Tβ4 fragment | Synthetic gastric-juice protein fragment |
| Characterised tissues | Cardiac, corneal, dermal, vascular | Tendon, ligament, gastric, vascular |
| Stability in solution | Stable at 2–8 °C reconstituted | Stable at 2–8 °C reconstituted |
Combination protocols
BPC-157 + TB-500 is the most-published combination in regenerative-peptide research, examined in laboratory models for complementary mechanisms (BPC-157 angiogenic / cytoprotective + TB-500 actin / cell-migration). Peptides Lab UK supplies separate vials and the KLOW (BPC + TB500 + GHK + KPV) 80 mg blend.
Sourcing & quality
Research-grade TB-500 must ship with batch-level HPLC purity, mass-spectrometry identity confirmation, and bacterial endotoxin quantification on an independent third-party Certificate of Analysis. Peptides Lab UK supplies all TB-500 batches with an Optima Labs (UK) Certificate of Analysis at typical 99.0–99.7% HPLC purity. The COA includes the chromatogram, MS identity result, endotoxin level, acetate counter-ion percentage, and net peptide content per the SOP referenced in our Research Quality Standards SOP.
Storage and reconstitution for laboratory use
Lyophilised TB-500 is stored at -20 °C and is stable for the duration stated on the COA when protected from light. Once reconstituted with bacteriostatic water for laboratory use, the solution is stored at 2–8 °C and used within the manufacturer-stated stability window. Avoid freeze-thaw cycles of reconstituted solution — peptide structure degrades with repeated thawing.
For reconstitution-volume calculations and U-100 insulin syringe unit conversions, use the Peptides Lab UK reconstitution calculator.
Reference content
- Buy TB-500 UK — research-grade SKU, COA per batch.
- KLOW (BPC + TB500 + GHK + KPV) 80 mg blend
- BPC + TB500 combination SKU
- BPC-157 Research Hub — companion reference
- Reconstitution calculator
FAQs — TB-500 in UK research
What is TB-500?
TB-500 is a synthetic fragment of Thymosin Beta-4, the most abundant intracellular actin-sequestering peptide in mammalian cells. It is examined in laboratory research for actin-binding, cell-migration, and tissue-research applications research models.
Is TB-500 legal in the UK?
TB-500 is not a controlled substance under the UK Misuse of Drugs Act 1971 and may be supplied for laboratory research use only. It is not authorised by the MHRA for human medicinal use.
What’s the difference between TB-500 and Thymosin Beta-4?
Thymosin Beta-4 is the full 43-amino-acid native protein. “TB-500” is commonly used to refer to either the active actin-binding fragment (LKKTETQ) or the full synthetic Tβ4 sequence — confirm with the supplier’s COA which is supplied. Peptides Lab UK supplies the synthetic full-length sequence.
Is the BPC-157 + TB-500 combination supported by research?
The combination is examined in laboratory regenerative-research models for complementary mechanisms; published research protocols vary. Peptides Lab UK supplies the combination as separate vials or as the KLOW 80 mg blend for laboratory researchers.
Last updated: 26 April 2026. Reviewed by William, Lead Research Editor, Peptides Lab UK. For in-vitro and preclinical research use only.
