TB-500 is a synthetic research peptide based on thymosin beta-4 (Tβ4), a 43-amino-acid protein that binds actin, the protein of the cell's internal skeleton.[8] Pepitiva supplies TB-500 as a lyophiliz...
Certificate of Analysis included with every order.
Technical Specifications
Purity
≥99%
Form
Lyophilized Powder
Storage
-20°C
About TB-500
TB-500 is a synthetic research peptide based on thymosin beta-4 (Tβ4), a 43-amino-acid protein that binds actin, the protein of the cell's internal skeleton.[8] Pepitiva supplies TB-500 as a lyophilized powder (10 mg vials, ≥99% purity) for in vitro and preclinical research.
What exactly is TB-500?
The name is used for two different molecules, and it is worth knowing which one a study or supplier means:
The Tβ4 fragment Ac-LKKTETQ: analytical work for doping control described the key ingredient of TB-500 as the peptide LKKTETQ with an acetylated N-terminus. This 7-residue segment (positions 17 to 23 of Tβ4) is the region responsible for actin binding, cell migration and wound healing. PubChem lists it with formula C38H68N10O14 and a molecular weight of 889.0 g/mol.[1][7]
Full-length thymosin β4: the 43-residue protein, molecular weight about 4963 g/mol.[8]
A 2023 analysis of products sold online as TB500 found that their content was not consistently what was described.[2] The identity and purity of each Pepitiva batch are documented in its Certificate of Analysis.
For research use only. Not for human consumption.
Quality & Storage
≥99% purity. Lyophilized Powder. Storage: -20°C. For research purposes only.
Mechanism of Action
Actin binding and cell migration
Thymosin β4 is a G-actin sequestering peptide. The LKKTETQ segment is the part of the protein responsible for binding actin and for its effects on cell migration.[1][4]
Findings with thymosin β4
Wound healing: in a rat full-thickness wound model, Tβ4 increased re-epithelialization by 42% at day 4 and up to 61% at day 7, with more collagen deposition and angiogenesis, and it stimulated keratinocyte migration 2- to 3-fold in vitro.[3]
Cardiac cell survival: Tβ4 formed a complex with PINCH and integrin-linked kinase, activated the survival kinase Akt and improved cardiac function after coronary ligation in mice.[4]
Vessel formation: Tβ4 was required for coronary vessel development in mice and stimulated outgrowth of adult epicardial progenitor cells.[5]
Most of this mechanistic work used full-length Tβ4, so results cannot automatically be transferred to the short fragment.
Research Applications
Preclinical findings with TB-500
Achilles tendon healing in rats (2026): TB-500 increased maximum load to failure and improved histological tendon scores against controls; the study also tested BPC-157 and the two peptides combined.[6]
Laboratory research applications
Actin dynamics: G-actin sequestering and cytoskeletal remodeling.
Cell migration assays: keratinocyte and endothelial migration.
Wound and tendon models: re-epithelialization, collagen organization and biomechanics.
Analytical method development: detection of Ac-LKKTETQ and its metabolites by LC-MS.[1]
Combination studies: with BPC-157 (available together as BPC-157 + TB-500) and the copper peptide GHK-Cu; the GLOW and KLOW blends include all three.
TB-500 is not approved by health authorities for human or veterinary use.[2] This product is sold for laboratory research only.
Storage & Handling Guidelines
Proper storage and handling are essential to maintain peptide integrity and ensure reliable research results. All Pepitiva Biolabs peptides are supplied as lyophilized (freeze-dried) powder, which provides excellent long-term stability when stored correctly. Store lyophilized peptides at -20°C for long-term storage or 2-8°C for short-term use. Once reconstituted, peptide solutions should be stored at 2-8°C and used within the timeframe specified in the product documentation. Always use sterile bacteriostatic water for reconstitution and handle peptides in a clean laboratory environment to prevent contamination. Avoid repeated freeze-thaw cycles, as thermal stress can cause peptide degradation and loss of biological activity.
Quality Control & Certification
This product is manufactured under strict quality control protocols and has been verified through comprehensive analytical testing. Each batch undergoes reverse-phase HPLC analysis for purity determination and electrospray ionization mass spectrometry (ESI-MS) for molecular identity confirmation. A detailed Certificate of Analysis (COA) is available for download, documenting purity percentage, molecular weight verification, appearance, and recommended storage conditions. Pepitiva Biolabs maintains batch-level traceability from synthesis through delivery, ensuring complete transparency and quality assurance for your research.
Frequently Asked Questions
What is TB-500?
A synthetic research peptide based on thymosin beta-4. In the analytical literature, its key ingredient is the N-acetylated fragment LKKTETQ (residues 17 to 23 of Tβ4), the region that binds actin.
Is TB-500 the same as thymosin beta-4?
Not necessarily. Thymosin beta-4 is a 43-amino-acid protein (about 4963 g/mol); the TB-500 described in doping-control studies is a 7-residue acetylated fragment (889.0 g/mol). Check the Certificate of Analysis for the exact identity of a batch.
What is the difference between TB-500 and BPC-157?
They are unrelated peptides. TB-500 is based on thymosin beta-4, an actin-binding protein; BPC-157 is a 15-amino-acid fragment of a gastric juice protein. See BPC-157.
Is TB-500 approved?
No. TB-500 is not approved for human or veterinary use, and methods have been developed to detect it in sports doping control.
How should TB-500 be stored?
Keep the lyophilized powder at −20 °C, protected from light and moisture.
Is this product approved for human use?
No. This product is intended exclusively for in vitro scientific research and laboratory use. It is not approved for human or veterinary use, not intended for diagnostic or therapeutic purposes, and should not be administered to humans or animals under any circumstances.
How do I reconstitute this peptide?
Add sterile bacteriostatic water slowly to the vial, directing the stream against the glass wall rather than directly onto the lyophilized powder. Gently swirl the vial until the powder is fully dissolved — do not shake vigorously. The recommended reconstitution volume depends on your desired concentration. Refer to the product documentation for specific guidance.
Can I get a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis is included with every order and is also available for download from the product page. The COA documents HPLC purity, mass spectrometry identity confirmation, batch number, production date, and storage recommendations.
Scientific References
Ho EN, Kwok WH, Lau MY, et al. Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry. J Chromatogr A. 2012;1265:57-69. PubMed
Delcourt V, et al. TB500/TB1000 and SGF1000: A scientific approach for a better understanding of misbranded and adulterated drugs. Drug Test Anal. 2023;15(4):458-464. PubMed
Malinda KM, Sidhu GS, Mani H, et al. Thymosin beta4 accelerates wound healing. J Invest Dermatol. 1999;113(3):364-368. PubMed
Bock-Marquette I, Saxena A, White MD, et al. Thymosin beta4 activates integrin-linked kinase and promotes cardiac cell migration, survival and cardiac repair. Nature. 2004;432(7016):466-472. PubMed
Smart N, Risebro CA, Melville AA, et al. Thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization. Nature. 2007;445(7124):177-182. PubMed
Biçer O, et al. Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study. Jt Dis Relat Surg. 2026;37(3):822-837. PubMed
Sources are peer-reviewed publications indexed in PubMed and trial registrations on ClinicalTrials.gov. Each citation was checked against its PubMed record.
For research use only. Not for human consumption.
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