TB-500 (Thymosin Beta-4): Peptide Profile, CAS & Properties
CAS 77591-33-4 · 4963.44 g/mol
TB-500 (Thymosin Beta-4) (CAS 77591-33-4) is a 43-amino-acid synthetic thymosin beta-4 fragment with molecular formula C212H350N56O78S (~4963.44 g/mol). It is a G-actin-sequestering peptide and is not approved by any major regulator for therapeutic use. This page provides reference information on TB-500 (Thymosin Beta-4).
- CAS Number
- 77591-33-4
- Molecular Formula
- C212H350N56O78S
- Molecular Weight
- 4963.44 g/mol
- Drug Class
- synthetic thymosin beta-4 fragment
What is TB-500 (Thymosin Beta-4)?
TB-500 is a synthetic analogue of thymosin beta-4 (Tβ4), a naturally occurring 43-amino-acid peptide found in nearly all mammalian cells. The molecule (CAS 77591-33-4, molecular formula C212H350N56O78S, ~4963.44 g/mol) is N-terminally acetylated and is the principal G-actin-sequestering peptide in many cell types, binding monomeric (globular) actin in a 1:1 complex and thereby modulating the pool of actin available for polymerisation into filaments. Through this actin-regulating activity and interactions with additional molecular partners, it has been studied in research models of cell migration, angiogenesis and tissue repair.
It is important to state the regulatory position clearly: TB-500 / thymosin beta-4 is not approved by the FDA, EMA or other major regulators for any therapeutic indication, and it is prohibited in sport under the WADA Prohibited List. No efficacy or therapeutic-benefit claims should be inferred from this reference information, which is provided for educational purposes only.
How TB-500 Is Produced & Characterised
At 43 residues with an acetylated N-terminus and a high content of glutamate and lysine, TB-500 is a synthetically demanding peptide in which deletion sequences, incomplete acetylation and closely related variants must be tightly controlled. In an industry setting this peptide class is typically produced by optimised Fmoc solid-phase peptide synthesis (SPPS), followed by preparative dynamic axial compression (DAC) HPLC purification to resolve the target sequence sharply from related impurities, and then lyophilisation to a stable, uniform powder.
Characterisation generally relies on UPLC/HPLC for purity determination and LC-MS for confirming the sequence and profiling minor structural variants. Controlled N-terminal acetylation and tight control of deletion sequences and related variants are central to producing a well-defined material with repeatable batch-to-batch consistency, from gram-scale research lots through to larger reference-standard campaigns.
Typical Quality Specifications & Impurity Control
Reference-grade peptides of this type are commonly released against a defined specification accompanied by a Certificate of Analysis (COA). Purity is typically determined by UPLC/HPLC, with the sequence and minor structural variants confirmed by LC-MS impurity profiling. A high-purity research material would typically target ≥99.0% purity, with individual impurities controlled below 0.10%, supported by ICH Q1A(R2) long-term and accelerated stability data.
Full traceability from raw materials and resins through to final batch-release records, analytical methods validated to ICH Q2(R1), and characterisation of water content, counter-ion (acetate) content, residual solvents and peptide content are typical hallmarks of well-defined material suitable for laboratory research and reference-standard use.
Regulatory Status & Handling
TB-500 / thymosin beta-4 is not an approved drug substance and is not approved by the FDA, EMA or other major regulators for any therapeutic indication. It is handled strictly for research and reference-standard purposes and is not represented as suitable for finished human pharmaceutical products. It is also prohibited at all times in sport under the WADA Prohibited List (class S2).
As a peptide, TB-500 is typically presented as a lyophilised powder, stored at -20°C protected from light and moisture, and transported via cold-chain logistics with temperature monitoring. This page is provided as general reference information on the molecule and its regulatory context only; it does not constitute dosing, medical or patient advice.
TB-500 (Thymosin Beta-4) API — Specifications
| Compound | TB-500 (Thymosin Beta-4) |
|---|---|
| CAS Number | 77591-33-4 |
| Molecular Formula | C212H350N56O78S |
| Molecular Weight | 4963.44 g/mol |
| Sequence | 43 amino acids, N-terminally acetylated |
| Drug Class | Synthetic thymosin beta-4 fragment (G-actin-sequestering peptide) |
| Appearance | White to off-white lyophilised powder |
| Typical Purity (HPLC) | ≥ 99.0% (single impurity < 0.10%) |
| Synthesis Route | Fmoc SPPS + DAC prep-HPLC purification |
| Regulatory Status | Not approved for therapeutic use; research / reference-standard only; WADA-prohibited (S2) |
| Form | Lyophilised powder; typically stored at -20°C, protected from light & moisture |
Reference data only — WinHyCare neither supplies nor manufactures this compound; see our Semaglutide API for the product we supply. Regulatory status: Not approved by the FDA, EMA or other major regulators for any therapeutic use. It is handled only as a research / reference-standard material. Thymosin beta-4 / TB-500 is also prohibited at all times in sport under the World Anti-Doping Agency (WADA) Prohibited List (class S2).
TB-500 (Thymosin Beta-4) API — Frequently Asked Questions
What is TB-500 (Thymosin Beta-4)?
TB-500 is a synthetic analogue of thymosin beta-4 (Tβ4), a naturally occurring 43-amino-acid peptide found in nearly all mammalian cells. It is N-terminally acetylated and acts as the principal G-actin-sequestering peptide in many cell types, binding monomeric (globular) actin in a 1:1 complex.
What is the CAS number and molecular weight of TB-500 (Thymosin Beta-4)?
TB-500's CAS number is 77591-33-4, its molecular formula is C212H350N56O78S, and its molecular weight is approximately 4963.44 g/mol. It is a 43-amino-acid synthetic thymosin beta-4 fragment with an N-terminally acetylated sequence.
Is TB-500 approved by the FDA or EMA?
No. TB-500 / thymosin beta-4 is not approved by the FDA, EMA or other major regulators for any therapeutic use. It is intended strictly for research and reference-standard purposes, and no efficacy or therapeutic-benefit claims should be inferred. It is also prohibited at all times in sport under the WADA Prohibited List (class S2).
What class of peptide is TB-500?
TB-500 is a synthetic thymosin beta-4 fragment — specifically a G-actin-sequestering peptide. It falls within the regenerative and repair peptide class and is studied in research models of cell migration, angiogenesis and tissue repair.
What is the mechanism of action of thymosin beta-4?
Thymosin beta-4 is the principal G-actin-sequestering peptide in many cell types. It binds monomeric (globular) actin in a 1:1 complex, regulating the pool of actin available for polymerisation into filaments, and is studied in research models of cell migration and tissue repair.
What is TB-500 being studied for?
Through its actin-regulating activity and interactions with additional molecular partners, thymosin beta-4 / TB-500 has been studied in research models of cell migration, angiogenesis and tissue repair and wound healing. These are research contexts only; it is not approved for any therapeutic use.
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Technical Reference Page
WinHyCare neither supplies nor manufactures TB-500 (Thymosin Beta-4); this page is provided as a technical reference. The peptide API we supply is Semaglutide.