LA LABResearch Reference Document
Compound Guide
TB-500 — Thymosin Beta-4 Fragment (Ac-LKKTETQ)
Quick Start
TB-500 ≠ Full Thymosin Beta-4
TB-500 is a 7-amino acid fragment of the full 43-AA Thymosin Beta-4 protein, corresponding to amino acids 17–23 (Ac-LKKTETQ). It is NOT the same compound as full-length Thymosin Beta-4. Research on the two compounds is not interchangeable. Most research vials sold as "TB-500" contain the fragment sequence.
What It Is
TB-500 is a synthetic 7-amino acid peptide fragment (Ac-LKKTETQ, residues 17–23 of Thymosin Beta-4). It is studied for effects on actin regulation, cell migration, angiogenesis, and inflammation modulation. The Thymosin Beta-4 protein is naturally found in high concentrations in blood platelets and wound fluid.
Protocol Structure
TB-500 research protocols use a loading phase followed by a maintenance phase. Loading: higher doses more frequently to build up tissue levels. Maintenance: lower frequency to sustain effects. This two-phase structure is common to most published TB-500/Tβ4 research.
Regulatory Status
FDA removed TB-500 from Category 2 bulk substance list effective April 15, 2026. PCAC review scheduled July 23, 2026 (wound healing indication). WADA banned (S0) with a detection window of approximately 30–45 days. Not approved for human therapeutic use in any major jurisdiction. For research purposes only.
Dosing Protocol
| Phase | Dose | Frequency | Duration | Notes |
|---|---|---|---|---|
| Loading | 2.0–2.5 mg | 2× per week (e.g. Mon + Thu) | 4–6 weeks | Build tissue levels; SubQ anywhere |
| Maintenance | 2.0–2.5 mg | Once per week | Ongoing | Reduce frequency once loading complete |
| Wash-out | — | — | 4+ weeks | Allow off-cycle before restarting |
Injection Site — Systemic vs Local
Unlike BPC-157 (which is often injected near the affected area), TB-500 is generally studied as a systemic compound — SubQ injection anywhere (abdomen, thigh) is considered equivalent, as it works through systemic actin regulation and cell migration signalling rather than local depot effects.
Supplies & Reconstitution
Reconstitution Math — 5 mg Vial (3 mL BAC)
| Target Dose | Units (U-100) | Doses / Vial |
|---|---|---|
| 1 mg | 60.0 units | 5 |
| 2 mg | 120.0 units | 2.5 |
| 2.5 mg | 150.0 units | 2 |
| 5 mg | 300.0 units | 1 |
Reconstitute the 5 mg vial with 3.0 mL bacteriostatic water → 1.67 mg/mL. U-100 syringe = 100 units per mL. Swirl gently — do not shake. Refrigerate 2–8°C.
Vial Planning Guide
| Dose per Injection | Frequency | Injections per 10 mg vial | Vials — 6 wk loading | Vials — 8 wk maintenance |
|---|---|---|---|---|
| 2.5 mg | 2× / week (loading) | 4 injections | 3 vials | 2 vials |
| 2.0 mg | 2× / week (loading) | 5 injections | 2–3 vials | 2 vials |
| 2.5 mg | 1× / week (maint.) | 4 injections | — | 2 vials |
Reconstitution Steps
01
Gather supplies
TB-500 vial, BAC water, U-100 insulin syringes, alcohol swabs. Remove peptide vial from freezer 10–15 min before use.
02
Swab rubber tops
Wipe both rubber stoppers (BAC water vial and peptide vial) with separate alcohol swabs. Allow to air-dry fully.
03
Draw BAC water
Draw 3.0 mL of BAC water into a syringe. For larger vial sizes or different concentrations, adjust volume accordingly.
04
Inject along the vial wall
Insert the needle at an angle into the peptide vial and let the BAC water run slowly down the inside glass wall. Never jet directly onto the powder — this degrades the peptide.
05
Swirl — do not shake
Gently swirl the vial in slow circles until the powder is fully dissolved and the solution is clear. Do not shake or vortex.
06
Refrigerate
Store reconstituted vial upright in the refrigerator at 2–8°C. Use within 30 days. Do not freeze after reconstitution.
Mechanism of Action
The active region of TB-500 (Ac-LKKTETQ) binds G-actin (unpolymerised actin monomers). This interaction underlies the key mechanisms studied in preclinical research:
G-Actin Sequestration
TB-500 binds free G-actin monomers, regulating the balance between G-actin and F-actin (polymerised). This modulates cytoskeletal dynamics in cells involved in tissue repair — including fibroblasts, endothelial cells, and keratinocytes.
Cell Migration
By regulating actin polymerisation, TB-500 promotes directional migration of repair cells to damaged tissue. Studied in endothelial cell migration assays and wound-healing animal models.
Angiogenesis
Promotes formation of new blood vessels into damaged tissue, studied in cardiac ischaemia and wound-healing models. Proposed to work synergistically with BPC-157's VEGFR2 pathway.
Anti-Inflammatory
Modulates inflammatory cytokine activity at injury sites. Studied in models of chronic wound healing and ischaemia-reperfusion injury. Mechanism not fully characterised for TB-500 fragment specifically.
Research Status & Evidence
No Human RCT Evidence for TB-500 Fragment
Published human clinical data exists for full-length Thymosin Beta-4 (43 AA) in wound healing and cardiac contexts. TB-500 (the 7-AA fragment Ac-LKKTETQ) does not have published human RCTs as of mid-2026. Research on the full-length protein cannot be directly applied to the fragment compound.
Regulatory Timeline
| Date | Event |
|---|---|
| April 15, 2026 | FDA removed TB-500 from 503A/503B Category 2 bulk substance list |
| July 23, 2026 | PCAC scheduled review for wound healing indication |
| 2022–present | WADA S0 banned; detection window ~30–45 days in urine/blood |
Storage
| State | Temperature | Duration | Notes |
|---|---|---|---|
| Lyophilised (powder) | −20°C (freezer) | Up to 24 months | Protect from light and moisture |
| Reconstituted (liquid) | 2–8°C (refrigerator) | Up to 30 days | Keep upright; do not re-freeze |
| Short-term (travel) | <25°C | Up to 72 hours | Avoid direct sunlight and heat |
Disclaimer
This document is an educational research reference only. It is not medical advice, not a treatment plan, and not a recommendation to use TB-500 outside of a qualified research or clinical context. TB-500 is banned by WADA for competitive athletes. By purchasing from LA LAB you confirm you are 18+ and that products are for research purposes only.