TB-500 (Thymosin Beta-4)

TB-500 is the name used for synthetic peptides derived from thymosin β4, a 43-amino-acid protein present in most human cells, where it binds actin. Depending on the supplier, TB-500 denotes either the full-length sequence or a short fragment around its actin-binding region (LKKTETQ). Check the Certificate of Analysis for the composition and molecular weight of each lot.

The World Anti-Doping Agency's Prohibited List names thymosin β4 and its derivatives, including TB-500, in class S2 (peptide hormones, growth factors, related substances and mimetics), which is prohibited in sport at all times. WADA bans substances that are not approved for human therapeutic use and that it considers capable of enhancing performance. TB-500 is not an approved medicine in any country.

They are unrelated molecules. BPC-157 is a synthetic 15-amino-acid peptide (GEPPPGKPADDAGLV) based on a partial sequence of a protein found in gastric juice. TB-500 is the name used for synthetic peptides derived from thymosin β4, a 43-amino-acid protein that binds actin inside cells; depending on the supplier it denotes the full-length sequence or a fragment around its actin-binding region. They differ in length, sequence, origin and the cellular pathways studied, and are often supplied together as a co-lyophilized blend for convenience in research.

Despite the shared name, they are unrelated. Thymosin alpha-1 is a 28-amino-acid acetylated peptide cleaved from prothymosin alpha and was first isolated from thymus tissue; it is studied in immunology research. Thymosin β4 is a 43-amino-acid protein from a different gene that binds actin inside cells; TB-500 refers to synthetic peptides derived from it. Both names come from the same 1960s–70s thymus extract (thymosin fraction 5) in which they were found.

These belong to unrelated research areas. BPC-157 (a 15-amino-acid gastric-protein-derived peptide) and TB-500 (derived from the actin-binding protein thymosin β4) are studied in tissue-repair models. CJC-1295, sermorelin and tesamorelin are GHRH analogues acting on the GHRH receptor in the growth hormone axis. They share no sequence, receptor or pathway.

Not always. Thymosin beta-4 (Tβ4) is a naturally occurring 43-amino-acid protein, acetylated at its N-terminus, with a molecular weight of about 4.96 kDa. TB-500 is a name used for synthetic material derived from it: some suppliers use it for the full-length synthetic sequence, others for a short fragment around the actin-binding region, such as Ac-LKKTETQ. Because the name is used loosely, the lot's Certificate of Analysis is the place to confirm which sequence and molecular weight a vial contains.

Most published research concerns thymosin beta-4, the parent protein, rather than TB-500 itself. In cell and rodent models it has been examined as an actin-sequestering protein in cell migration, blood-vessel formation, and repair models of skin, cornea and heart tissue. Thymosin β4 has also been investigated in clinical trials in people with dry eye disease and neurotrophic keratopathy. TB-500 itself has not been through clinical development, and findings in cells or animals do not establish effects in people.

No. Neither TB-500 nor thymosin β4 is approved by the FDA, and TB-500 is not an approved medicine in any country, so there is no approved prescription product containing it. It is also on the World Anti-Doping Agency's Prohibited List. The material sold here is a research reagent for laboratory use only.

TB-500 refers to synthetic peptides derived from thymosin β4, a 43-amino-acid actin-binding protein, either full length or as a short fragment. KPV is a three-amino-acid peptide (Lys-Pro-Val) from the C-terminal end of α-MSH. They differ in size, origin and the pathways studied: actin dynamics and cell migration for thymosin β4, inflammatory signaling such as NF-κB for KPV. Both are components of the four-peptide blend we sell.

Ara-290 is an 11-amino-acid peptide derived from erythropoietin that targets the proposed innate repair receptor on the cell surface. TB-500 refers to synthetic peptides derived from thymosin β4, a 43-amino-acid protein that binds actin inside cells. They differ in origin, size and target; Ara-290 has been through phase 2 clinical trials, while TB-500 has not been through clinical development.

TB-500 (Thymosin Beta-4): molecular formula C212H350N56O78S (full-length thymosin beta-4); molecular weight 4963.4 g/mol (full-length thymosin beta-4); 858.0 g/mol (Ac-LKKTETQ fragment); CAS number 77591-33-4. Sequence: Ac-SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES (full-length thymosin beta-4); Ac-LKKTETQ (TB-500 short fragment). Match these identifiers against the Certificate of Analysis for the lot.

Yes. Each lot has its own Certificate of Analysis, linked on this page for the current lot of each size: 5mg (99.88% HPLC purity); 10mg (99.48% HPLC purity). Past certificates are archived in the COA library; contact us with the lot number on the vial label if a certificate is missing.

99.48% (HPLC, current lot). Purity is measured by high-performance liquid chromatography (HPLC) and reported on the lot's Certificate of Analysis.

TB-500 (Thymosin Beta-4) is supplied as lyophilized powder in a sealed vial in 2 sizes: 5mg, 10mg. In stock and dispatched in 1–2 business days. Quantity pricing applies automatically at 5+ and 10+ vials of the same size.

Store sealed at −20 °C, dry and protected from light.