TB-500 (Thymosin Beta-4)
Molecular Research Profile ยท Target purity > 99.0% ยท Half-life Intermediate
Promotes actin upregulation, cellular migration, and rapid systemic injury recovery. Synergizes strongly with BPC-157.
TB-500 (Thymosin Beta-4) Molecular Formula, Structure & Chemical Identity
Reference identifiers researchers use to verify that a vial matches what a vendor claims to have shipped. Cross-check these values against any Certificate of Analysis before accepting a purity figure.
| Molecular Formula | C38H68N10O14 |
|---|---|
| Molecular Weight | 889.0 g/mol |
| CAS Number | 885340-08-9 |
| Amino Acid Count | 7 |
| Amino Acid Sequence | Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln |
| Sequence (1-letter) | LKKTETQ |
| Also Known As | Thymosin Beta-4 fragment, TB500, Ac-LKKTETQ |
| PubChem CID | 62707662 ↗ |
NOTE: TB-500 is the synthetic Ac-LKKTETQ fragment, not full-length Thymosin Beta-4 (C212H350N56O78S, 4963 g/mol, CAS 77591-33-4). Vendors use the names interchangeably; the specs differ.
Identifiers verified against the NIH PubChem compound database. Molecular weights independently recalculated from the molecular formula using IUPAC 2021 standard atomic weights.
How to Read a TB-500 (Thymosin Beta-4) Certificate of Analysis
A COA is only meaningful if the identifiers on it match the compound you ordered. Four checks, in order.
- 1. Identity โ does the formula match?The COA header should state C38H68N10O14 and a molecular weight near 889.0 g/mol, with CAS 885340-08-9. A mismatch means you are not looking at a COA for this compound.
- 2. Purity โ HPLC chromatogram, not just a numberA printed “> 99.0%” with no chromatogram is a marketing claim. Demand the actual HPLC trace: a single dominant peak, labelled retention time, and an integration table. Shoulders or unlabelled side peaks are unreported impurities.
- 3. Mass confirmation โ does MS agree with the formula?Mass spectrometry should report an observed mass consistent with the expected 889.0 g/mol. Peptides are frequently reported as multiply charged ions, so the raw m/z value will be lower than the neutral mass. An unexplained offset is a red flag.
- 4. Provenance โ who signed it, and for which batch?A valid COA names the testing laboratory, carries a batch or lot number that matches your vial label, and is dated. A vendor-produced PDF with no lab identity and no batch number is not third-party evidence.
Full methodology in ourguide to the 5 COA red flags researchers miss, or verify the reconstitution math with thepeptide reconstitution calculator.
Mechanism of Action
TB-500 is a synthetic fragment of thymosin beta-4, a naturally occurring 43-amino-acid peptide present in virtually all mammalian cells. Its primary mechanism is actin sequestration and polymerization โ it binds G-actin monomers and regulates their assembly into F-actin filiaments, which are essential for cell migration, wound contraction, and cytosceletal remodeling.
Beyond actin regulation, TB-500 promotes keratinocyte and endothelial cell migration, reduces inflammation through suppression of NF-kB signaling, and upregulates matrix metaloproteinases involved in tissue remodeling. In animal models, it has demonstrated accelerated hair-follicle regeneration, dermal wound closure, and corneal healing. Its systemic distribution contrasts with BPC-157's more localized effects, making it complementary in multi-peptide research protocols.
Research History & Context
Thymosin beta-4 was first identified in the 1980s as a thymic hormone, though its ubiquituous tissue distribution and actin-binding properties later reclassified it as a cytosceletal regulatory peptide rather than an immune mediator. The synthetic fragment TB-500 has been studied in veterinary medicine (particularly equine tendon and ligiament repair) since the early 2000s.
Research on TB-500 in combination with BPC-157 โ the so-called "Wolverine Stack" in biohacking nomenclature โ has shown synergistic effects on wound-healing acceleration in rodent models, with combined administration outperforming either peptide alone on metrics of tensile strength and collagen organization.
Storage & Handling
Store lyophilized TB-500 at -20ยฐC in a desiccated, light-protected container. Stability exceeds 24 months under these conditions. The peptide is moderately hygroscopic โ minimize vial-open time in humid environments.
After reconstitution with bacteriostatic water, TB-500 should be refrigerated at 2โ8ยฐC and used within 21 days. Some protocols extend to 28 days, but peptide stability studies suggest a modest decline in bioactivity after day 21. Aliquotting and freezing at -20ยฐC is acceptable for single-use aliquots (avoid refreezing).
Reconstitution & Research Dosing
For TB-500 (Thymosin Beta-4), the standard laboratory reconstitution is 2.0 ml BAC water for 5mg / 10mg vial. A typical research study window uses 2.0 - 5.0 mg / twice weekly.
For a 5mg TB-500 research vial, add 2.0 ml BAC water (2.5 mg/ml). For a 10mg vial, add 2.0 ml BAC water (5.0 mg/ml). Due to the twice-weekly research protocol, many researchers reconstitute and immediately aliquot into two sterile vials โ one for week 1, one frozen for week 2 โ to minimize degradation.
Use the Reconstitution Calculator for exact syringe units →Audited Vendors Stocking TB-500
Each review checks whether the testing lab is named and whether COAs can be verified at the issuing lab.
Related TB-500 Research
TB-500 FAQ
QWhat is the molecular formula of TB-500 (Thymosin Beta-4)?
TB-500 (Thymosin Beta-4) has the molecular formula C38H68N10O14 and a molecular weight of approximately 889.0 g/mol. Its CAS registry number is 885340-08-9. It is a 7-residue peptide with the sequence Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln.
QHow do you verify a TB-500 (Thymosin Beta-4) Certificate of Analysis?
Check four things in order. First, identity: the COA must state C38H68N10O14 and CAS 885340-08-9. Second, purity: require the actual HPLC chromatogram with retention time and integration table, not just a printed percentage. Third, mass confirmation: the mass spectrometry result must agree with the expected molecular weight of 889.0 g/mol, allowing for multiply charged ions. Fourth, provenance: the COA must name the testing laboratory and carry a batch number matching your vial label.
QWhat purity should TB-500 (Thymosin Beta-4) be?
Research-grade TB-500 (Thymosin Beta-4) should meet a purity target of > 99.0%, confirmed by third-party HPLC analysis rather than a vendor self-declaration. A purity claim without an accompanying chromatogram carries no evidential weight.
QHow much bacteriostatic water do you add to TB-500 (Thymosin Beta-4)?
The standard reconstitution for TB-500 (Thymosin Beta-4) is 2.0 ml BAC water for 5mg / 10mg vial. For a 5mg TB-500 research vial, add 2.0 ml BAC water (2.5 mg/ml). For a 10mg vial, add 2.0 ml BAC water (5.0 mg/ml). Due to the twice-weekly research protocol, many researchers reconstitute and immediately aliquot into two sterile vials โ one for week 1, one frozen for week 2 โ to minimize degradation.
Explore Related Research Compounds
Research Use Only (RUO): TB-500 (Thymosin Beta-4) is discussed strictly as an in-vitro laboratory research compound. Nothing on this page constitutes human or clinical administration guidance. Always verify purity through independent third-party HPLC/MS analysis before use.