What is TB-500?

What TB-500 is

TB-500 is the name commonly used in the research peptide market for a synthetic peptide related to thymosin beta-4, a small, naturally occurring protein found widely across cell types in many organisms. Thymosin beta-4 itself is a 43-amino-acid protein, and doping-control literature identifies TB-500 as the N-acetylated seven-residue fragment Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (Ac-LKKTETQ), matching residues 17 to 23, the actin-binding region of the parent protein. It is manufactured by solid-phase peptide synthesis rather than extracted from tissue. Some vendors sell full-length thymosin beta-4 under the same name, so the sequence on a listing matters more than the name.

Actin binding

The central biochemical property studied in thymosin beta-4 research is its ability to bind monomeric (G-actin) actin, one of the most abundant and fundamental structural proteins in animal cells. Actin exists in a dynamic equilibrium between its monomeric form and long polymer filaments (F-actin) that make up much of the cell's cytoskeleton, the internal scaffolding that gives a cell its shape and allows it to move.

By binding G-actin, thymosin beta-4 acts as what researchers call an actin-sequestering protein, effectively holding a pool of actin monomers in reserve and influencing how quickly and where new actin filaments can be assembled. This mechanism is a well-established area of cell biology research independent of any specific commercial product.

Cell migration and cytoskeletal remodelling

Because actin filament assembly and disassembly underlie how a cell changes shape and moves, thymosin beta-4 and TB-500 are studied in laboratory research on cell migration, a process examined extensively in cell culture models using techniques such as time-lapse microscopy and scratch-wound assays. This research also extends to cytoskeletal remodelling more broadly, meaning how the internal actin network reorganises in response to different signals within a cell model.

For the TB-500 fragment, this literature is grounded in cell biology and preclinical animal model studies; it describes mechanisms observed under laboratory conditions and does not constitute evidence of an effect established in human clinical use. A Phase 1/2 trial of TB-500 itself (NCT07487363) has been recruiting since March 2026, with no results yet. Full-length thymosin beta-4 has separately been tested in human trials, so findings for the full protein should not be read as findings for TB-500.

Synthesis and characterisation

As a synthetic research peptide, TB-500 is produced by solid-phase peptide synthesis. Peptides of this kind are typically characterised by HPLC for purity and by mass spectrometry or a reference standard for identity. Celyfe's published WOLVERINE certificate (batch C26071) is a third-party HPLC report giving 99% purity and a measured TB-500 content of 4.25mg/ml, 85% of the 5mg/ml label; it does not include mass spectrometry.

How Celyfe supplies TB-500

Celyfe includes TB-500 at 15mg per 3ml cartridge in its WOLVERINE Pen (alongside BPC-157), its GLOW Pen and its KLOW Pen (alongside GHK-Cu, BPC-157, and in KLOW's case also KPV), each shipped cold-chain and stored refrigerated between 2 and 8 degrees Celsius in line with standard in-solution peptide stability practice.

Research use only

TB-500 supplied by Celyfe is intended for laboratory and research use only. It is not an approved medicine, and nothing in this guide describes or implies its use in or on a human or animal body.