TB-500 Compound Reference
Published · Last updated · Publisher: ENOS Labs USA
What is TB-500?
TB-500 is a commercial name for synthetic material related to thymosin beta-4, a naturally occurring 43 residue protein that binds actin. Published work concerns thymosin beta-4 itself, mostly in cell and animal models of tissue repair, with some ophthalmic clinical studies. TB-500 is not an approved drug, and its exact composition varies by source.
- Synonyms
- Thymosin beta-4 fragment; Thymosin β4 (Tβ4) related peptide
- Classification
- Synthetic peptide related to thymosin beta-4, a 43 residue actin binding protein
What is TB-500?
Thymosin beta-4 is one of the most abundant intracellular actin sequestering proteins. The name TB-500 is used in the research chemical market for synthetic thymosin beta-4 or for shorter fragments containing its actin binding region, so the label alone does not define the sequence.
Research context
The literature studies thymosin beta-4 in cell migration, wound repair, corneal injury and cardiac and kidney models. Ophthalmic research has progressed furthest toward clinical evaluation.
Mechanisms being investigated
- Sequestering monomeric G-actin and so regulating actin polymerization and cell motility.
- Effects on cell migration and angiogenesis reported in tissue repair models.
Research status
Approval status: Not approved for human use. Highest evidence tier in the cited literature: preclinical and early human.
Thymosin beta-4 has been evaluated in early clinical studies, notably in eye disease, but it is not approved by the FDA for any use. Material sold as TB-500 is a research chemical and is not the same as any investigational clinical product.
Established findings
- Thymosin beta-4 binds G-actin and is a major regulator of the cellular actin pool.
- Its full length structure is documented in PubChem.
Preliminary or experimental findings
- Repair and regeneration effects reported in animal models.
- Outcomes from early ophthalmic clinical studies, which have not led to an approval.
- Whether short fragments sold as TB-500 behave like the full protein.
Chemical reference information
| Molecular formula | C212H350N56O78S |
|---|---|
| Molecular weight | 4963 g/mol |
| PubChem CID | 45382195 |
Values taken from the PubChem record. Values are for full length thymosin beta-4. Products labeled TB-500 may be a fragment, so the expected mass must come from the sequence actually supplied.
Testing considerations
- Confirm which sequence is in the vial: full length protein and fragments have very different masses.
- N terminal acetylation changes the expected mass and should be stated.
- Methionine oxidation is a common related impurity.
General methods are explained in purity versus identity testing.
What is still unknown
- The sequence of many TB-500 products, which is often not disclosed.
- Whether fragment activity matches the parent protein.
Related resources
ENOS catalog listing: TB-500 10MG, BPC-157 + TB-500 "Wolverine" 20MG
Research use limitations
This page summarizes published research and regulatory status. It is not medical advice and does not describe any use in people. Material supplied by ENOS Labs USA is for in-vitro laboratory research only and is not a drug product, even where a related drug has been approved.
To continue, see BPC-157 and TB-500 compared, how to read a certificate of analysis, why purity and identity are separate tests, the compound directory and the peptide testing glossary.
References
Each source below was opened and checked against its PubMed, ClinicalTrials.gov or PubChem record. Links open in a new tab.
- Thymosin beta4: actin-sequestering protein moonlights to repair injured tissues (PMID 16099219)Trends in Molecular Medicine, 2005 · PubMed
- Thymosin beta 4 and the eye: the journey from bench to bedside (PMID 30063853)Expert Opinion on Biological Therapy, 2018 · PubMed
- Thymosin beta-4 compound record (PubChem CID 45382195)PubChem · NIH National Library of Medicine
These products are sold strictly for in-vitro laboratory research and are not intended for human consumption, diagnosis, treatment, or any therapeutic use. Purchaser must be 18 years of age or older and confirms they are a qualified researcher.