TB-500 (also written tb 500 with a space or tb500 joined) is one of the most searched research peptides in Europe in 2026. It is a synthetic peptide fragment derived from Thymosin Beta-4 (Tβ4), an actin-binding molecule that plays a central role in cell migration, angiogenesis and tissue repair. This 2026 guide covers everything a European laboratory purchaser needs before buying: what the tb-500 molecule actually is, how the three spellings relate to the same compound, the mechanism of action described in preclinical research, dosage and reconstitution protocols, the EU regulatory framework, and where to buy TB-500 online in Europe with verified Janoshik COA — without a medical prescription under the Research Use Only (RUO) framework.
What is TB-500 (tb 500 / tb500)?
Before we go into biochemistry, one quick clarification. Search engines and researchers use three different spellings interchangeably: TB-500 (with hyphen, the original supplier notation), tb 500 (with a space, common in typed queries) and tb500 (joined, common on mobile). All three refer to the same synthetic peptide. Throughout this article we use all three spellings so that whichever variant you searched for is unambiguous.
Chemically, tb-500 as sold by peptide suppliers is a synthetic peptide fragment based on Thymosin Beta-4. Thymosin Beta-4 (Tβ4) itself is a naturally occurring 43 amino acid peptide first isolated from calf thymus in the 1980s and later identified as one of the most abundant actin-binding proteins in mammalian cells. The commercial "TB-500" product typically refers to the active LKKTETQ region — a fragment corresponding to residues 17-23 of Tβ4 — with molecular weight around 888 Da. Some vendors, however, sell the full-length Tβ4 (~4963 Da) under the same TB-500 label. Always check the COA of the specific tb 500 vial you are buying to confirm which of the two versions you have.
| Attribute | Value |
|---|---|
| Chemical name | TB-500 / tb 500 / tb500 (Thymosin Beta-4 fragment) |
| Parent protein | Thymosin Beta-4 (Tβ4), 43 amino acids |
| Active fragment sequence | LKKTETQ (Tβ4 residues 17-23) |
| Molecular weight (fragment) | ~888 Da |
| Molecular weight (full Tβ4) | ~4963 Da |
| Molecular class | G-actin sequestering peptide / actin monomer-binding |
| Primary molecular target | G-actin monomer pool, actin polymerization dynamics |
| Plasma half-life | ~2-3 hours (fragment) |
| Pepspan format | Lyophilized vial 5mg, 79€ |
| Purity specification | >99% HPLC (Janoshik verified per batch) |
Historical and scientific background
The story of tb-500 begins with the isolation of Thymosin Beta-4 from calf thymus tissue in the early 1980s. Researchers working on thymic hormones identified Tβ4 as one of the most abundant actin-binding proteins in mammalian tissues, present at millimolar concentrations in the cytoplasm of many cell types. It quickly became a subject of intense study for its role in actin polymerization dynamics — the fundamental process behind cell movement, division and shape change.
By the 1990s and 2000s, researchers identified a shorter, highly bioactive region within Tβ4 — the LKKTETQ sequence corresponding to residues 17-23. This fragment retained a significant portion of the parent molecule's actin-binding and cell-migration-promoting activity. The synthetic version of this fragment was later commercialized as TB-500, initially in veterinary applications (particularly equine research) before spreading to general preclinical research. Today, tb 500 is one of the most studied "recovery research" peptides in the preclinical peptide literature, alongside BPC-157.
Mechanism of action
The primary mechanism described in preclinical research involves binding to G-actin monomers. Actin exists in cells in two forms: G-actin (monomeric, globular) and F-actin (filamentous, polymerized). The balance between the two dictates how cells move, divide and rebuild their cytoskeleton. TB-500 binds free G-actin and modulates its availability for polymerization into F-actin filaments.
Additional mechanisms described in the literature include:
- Cell migration promotion — by modulating cytoskeletal dynamics, tb-500 facilitates the migration of endothelial cells, keratinocytes and progenitor cells toward sites of tissue damage in wound healing models.
- Angiogenesis — preclinical studies have documented upregulation of VEGF and other pro-angiogenic factors, associated with the formation of new blood vessel networks in models of ischemic tissue.
- Anti-inflammatory signaling modulation — several papers describe a reduction of pro-inflammatory cytokines in preclinical injury and repair models.
- Cardiac and vascular repair models — Tβ4 (the parent protein of tb500) has been extensively studied in preclinical cardiac ischemia-reperfusion research.
Important: All these effects have been described in preclinical models (cell cultures, animal studies). Pepspan sells TB-500 strictly under the Research Use Only (RUO) status — it is not an authorized medicine, it is not intended for human consumption, and Pepspan does not provide any clinical advice.
Research applications
tb-500 is used across several lines of preclinical research:
1. Recovery research
The most cited application. Preclinical models of muscle strain, tendon injury and cutaneous wound healing use tb 500 to study cell migration and tissue reconstitution parameters. This is the origin of tb-500's reputation as a "recovery" peptide.
2. Tissue repair research
Wound healing models — cutaneous, corneal, gastric — use TB-500 to study epithelial and endothelial cell migration, granulation tissue formation and matrix remodeling. Diabetic wound models are particularly common in the tb500 literature.
3. Angiogenesis research
Preclinical models of ischemic tissue (limb ischemia, myocardial infarction) use TB-500 to study VEGF upregulation, endothelial cell migration and the formation of new vascular networks.
4. Cardiovascular research models
Full-length Thymosin Beta-4, closely related to tb-500, has been extensively studied in animal models of cardiac ischemia-reperfusion injury and post-infarct cardiac remodeling, exploring its capacity to promote cardiomyocyte survival and vascular regeneration.
TB-500 fragment vs full Tβ4 vs BPC-157 comparison
Researchers frequently compare tb-500 with two closely related molecules — the full-length parent protein Tβ4 and the pentadecapeptide BPC-157. Here is a side-by-side summary:
| Feature | TB-500 (fragment) | Full Thymosin Beta-4 | BPC-157 |
|---|---|---|---|
| Length | 7 aa (LKKTETQ) | 43 aa | 15 aa |
| Molecular weight | ~888 Da | ~4963 Da | ~1419 Da |
| Origin | Synthetic Tβ4 fragment | Recombinant / synthetic | Fragment of gastric protective protein |
| Primary mechanism | G-actin sequestration | G-actin sequestration, cardiac progenitor activation | NO / growth factor modulation |
| Main research area | Recovery, wound healing, angiogenesis | Cardiac repair, angiogenesis | Gastrointestinal, tendon/musculoskeletal repair |
For a full deep-dive on the two most-studied recovery peptides, see our detailed BPC-157 vs TB-500 comparison.
Reconstitution protocol for TB-500
TB-500 is shipped as a white lyophilized powder. Standard reconstitution protocol for preclinical research:
- Bring both vials to room temperature (20-25°C) before opening. Cold vials can cause moisture condensation on the powder.
- Calculate the diluent volume for your desired concentration. Examples:
- 5mg tb-500 + 2ml bac water = 2.5 mg/ml
- 5mg tb-500 + 5ml bac water = 1.0 mg/ml
- Aseptic technique: disinfect both septums with 70% isopropanol. Use a sterile syringe.
- Inject the bacteriostatic water slowly along the inner wall of the tb500 vial — never directly onto the powder.
- Swirl gently until fully dissolved. Do not shake vigorously — shaking can denature peptide structure and generate foam.
- Store immediately at 2-8°C. Do not leave at room temperature. Use within 28 days.
In preclinical animal research, typical doses reported in the literature range from 0.1 to 2 mg/kg administered subcutaneously, often once or twice per week. Pepspan does not provide dosage recommendations for human use.
Storage protocol
Correct storage preserves both purity and biological activity:
- Lyophilized (unopened) vials: stable at 4°C for several months. For long-term storage (years), keep at -20°C in the original packaging, protected from light.
- Reconstituted TB-500: store at 2-8°C in a refrigerator. Use within 28 days. Do not freeze reconstituted solution — freeze-thaw cycles degrade peptide stability.
- Transport: Pepspan ships lyophilized tb-500 at ambient temperature; the peptide is stable in this state for the duration of intra-EU shipping.
Where to buy TB-500 online in Europe (2026)
In Europe, tb-500 is sold as a laboratory reagent under Research Use Only (RUO) — it is not an authorized medicine. This means European pharmacies do not stock TB-500 (queries like "tb 500 farmacia" or "tb-500 kaufen apotheke" will not find a pharmacy source), and the realistic acquisition route is through specialized research peptide suppliers online.
When buying TB-500 online in Europe in 2026, key criteria to check are:
- EU stock and shipping origin: a European warehouse means no customs friction, no import duties and no risk of shipment seizure by national customs — critical for research continuity.
- Third-party Certificate of Analysis (COA): insist on an independent lab COA, not just a supplier self-declaration. Janoshik Analytical (Brno, Czechia) is the reference in European research peptides.
- Batch-level testing: HPLC purity, mass spectrometry identity, endotoxin (LAL) and microbial screening — all per batch, not just per SKU.
- Business substance: a real registered company with a company number you can verify — Pepspan Ltd is registered in England & Wales under Company Number 17144153.
- Transparent pricing: clear retail and wholesale tiers, no hidden fees.
Pricing at Pepspan (2026):
- TB-500 5mg lyophilized vial: 79€ per vial
- Wholesale (10+ units of the same SKU): automatic 20% discount = 63.20€/unit
- Free shipping: orders above 100€
- Shipping across Europe: European stock, no customs friction across EU/EEA
- Janoshik COA included with every order
For research clinics, university labs or distributors with recurring volume, Pepspan offers custom conditions — contact [email protected].
Regulatory framework in the EU
tb500 is legally sold across the 27 EU member states + EEA as a laboratory reagent under the Research Use Only (RUO) framework. It is not authorized as a medicine by the EMA (European Medicines Agency), nor by national medicines authorities such as AEMPS (Spain), ANSM (France), BfArM (Germany) or AIFA (Italy). It cannot be marketed, prescribed or used for human consumption.
When purchasing TB-500, the customer confirms:
- Being a qualified researcher, laboratory professional or working in R&D
- Using the product exclusively for scientific research
- Understanding and accepting the RUO framework and Pepspan's warnings
Detailed legal framework: Legal status of research peptides in Europe.
Alternative names and spellings for TB-500
Because tb-500 is searched with many spelling variants, here is the definitive list of names that all refer to the same synthetic Thymosin Beta-4 fragment:
- TB-500 — the original supplier notation with hyphen
- tb 500 — with a space, common in typed Google queries
- tb500 — joined, common on mobile typing
- Thymosin Beta-4 fragment — the biochemically accurate name
- Tβ4 (17-23) — scientific notation for the LKKTETQ fragment
- LKKTETQ peptide — the amino acid sequence itself
If you see the term "TB-500" used interchangeably with "full-length Tβ4" on some vendor sites, verify which molecule is actually in the vial by checking the COA molecular weight (~888 Da for the fragment vs ~4963 Da for full Tβ4).
Buy TB-500 at Pepspan — product range
TB-500 and related recovery research peptides:
- TB-500 5mg lyophilized vial — 79€ (63.20€ wholesale 10+ units)
- BPC-157 5mg (companion recovery peptide) — 59€
- KLOW Blend (BPC-157 + TB-500 + KPV + GHK-Cu preclinical stack)
- Bacteriostatic Water 10ml (required for reconstitution) — 12.90€
All products: Janoshik COA per batch, European stock, intra-EU shipping without customs. Sold under Research Use Only (RUO).
Frequently asked questions
What is TB-500 (also written tb 500 or tb500)?
TB-500 is written multiple ways online — as TB-500, tb 500 (with space), or tb500 (joined). All refer to the same synthetic peptide: a fragment (LKKTETQ, residues 17-23) of Thymosin Beta-4, an actin-binding peptide. Molecular weight ~888 Da for the fragment. Studied in preclinical recovery, wound healing and angiogenesis research.
How does TB-500 work?
The mechanism described in preclinical research involves binding to G-actin monomers, modulating actin polymerization and cytoskeletal dynamics. Downstream effects include promotion of cell migration, angiogenesis (VEGF upregulation) and tissue repair in preclinical injury models.
Where to buy TB-500 online in Europe?
Pepspan sells TB-500 5mg lyophilized at 79€/vial, EU stock, Janoshik COA per batch. Shipping to all 27 EU/EEA countries without customs. Wholesale 10+ vials = automatic 20% discount. No prescription needed under the RUO framework.
Is TB-500 legal in Europe?
Yes. Sold legally in the EU/EEA as a laboratory reagent under Research Use Only (RUO). Not authorized as a medicine by the EMA or national medicines authorities. No prescription needed for research acquisition. Buyer must be a qualified researcher.
What is the typical preclinical TB-500 dosage?
In preclinical animal research: 0.1-2 mg/kg subcutaneously, often once or twice weekly. Reconstitution with bacteriostatic water before use. Half-life ~2-3 hours. Pepspan does not provide dosage recommendations for human use.
How to store TB-500?
Lyophilized: 4°C for months / -20°C for years. Reconstituted: 2-8°C, use within 28 days. Never freeze reconstituted solution. Protect from direct light.
TB-500 vs BPC-157 — what is the difference?
TB-500 is a synthetic fragment of Thymosin Beta-4 that acts via G-actin sequestration and is more associated with vascular / systemic tissue repair research. BPC-157 is a 15 amino acid fragment of a gastric protective protein, acting through nitric oxide and growth factor pathways, and is more studied in gastrointestinal and musculoskeletal repair models.
How to reconstitute TB-500?
Room temperature → calculate diluent volume (5mg + 2ml = 2.5 mg/ml) → inject bacteriostatic water along the vial wall (never onto the powder) → swirl gently → store at 2-8°C, use within 28 days.
What is the price of TB-500 in Europe?
Pepspan: 79€ per 5mg vial. Wholesale 10+ units: 63.20€/unit (automatic 20% discount). Free shipping over 100€. VAT included where applicable.
All products on this site are sold exclusively for research purposes. Not intended for human or animal consumption. Must be handled by qualified professionals. Keep out of reach of children. By purchasing, you confirm you are a qualified researcher and use these products only for scientific research.