{"kind":"compound","id":"thymosin-beta-4","name":"Thymosin beta-4","url":"https://costides.us/us/research/thymosin-beta-4","last_verified":"2026-08-29","identity":{"cas":"77591-33-4","formula":"C212H350N56O78S","mw":4963,"sequence":null,"sequence_3letter":null,"residues":null,"pubchem":45382195,"identity_note":null,"parent_ligand":null},"chunks":[{"id":"lead-thymosin-beta-4","type":"definition","heading":"What is Thymosin beta-4?","text":"Thymosin beta-4 (timbetasin; CAS 77591-33-4) is the 43-residue N-acetyl protein (average MW 4963). It is not Costides SKU TB5. TB-500 (SKU TB5) is the synthetic N-acetyl heptapeptide Ac-LKKTETQ (CAS 885340-08-9; average MW 889.0), corresponding to residues 17–23 of thymosin beta-4. Research use only; not for human or veterinary use.","words":49},{"id":"def-thymosin-beta-4","type":"definition","heading":"Thymosin beta-4 overview","text":"Thymosin beta-4 (timbetasin; CAS 77591-33-4) is the 43-residue N-acetyl protein (average MW 4963). It is not Costides SKU TB5. TB-500 (SKU TB5) is the synthetic N-acetyl heptapeptide Ac-LKKTETQ (CAS 885340-08-9; average MW 889.0), corresponding to residues 17–23 of thymosin beta-4. Research use only; not for human or veterinary use. Synonyms and vendor codes indexed here include TB4, Tβ4, Timbetasin, Fx peptide. This page does not describe administration or dosing.","words":69},{"id":"id-thymosin-beta-4","type":"identity","heading":"Thymosin beta-4 chemical identity","text":"Thymosin beta-4 chemical identity: CAS 77591-33-4; formula C212H350N56O78S; average MW 4963 Da; PubChem CID 45382195. Values come from the Costides peptide research index.","words":23},{"id":"policy-thymosin-beta-4","type":"policy","heading":"Research Use Only","text":"Research Use Only. Not for human or veterinary use. This page indexes chemical identity and citations. It is not medical advice and does not describe administration or dosing.","words":28},{"id":"pass-what-thymosin-beta-4","type":"definition","heading":"What is Thymosin beta-4?","text":"Thymosin beta-4 (timbetasin; CAS 77591-33-4) is the 43-residue N-acetyl protein (average MW 4963). It is not Costides SKU TB5. TB-500 (SKU TB5) is the synthetic N-acetyl heptapeptide Ac-LKKTETQ (CAS 885340-08-9; average MW 889.0), corresponding to residues 17–23 of thymosin beta-4. Research use only; not for human or veterinary use.","words":49},{"id":"pass-human-thymosin-beta-4","type":"definition","heading":"Is Thymosin beta-4 for human use?","text":"No. Thymosin beta-4 (TB4) pages on Costides are Research Use Only reference materials. They are not medical advice and do not describe administration or dosing.","words":25},{"id":"pass-cas-thymosin-beta-4","type":"definition","heading":"What is the CAS number of Thymosin beta-4?","text":"The CAS number of Thymosin beta-4 (TB4) is 77591-33-4. Formula and molecular weight appear in the identity table when retrieved.","words":20},{"id":"pass-mw-thymosin-beta-4","type":"definition","heading":"What is the molecular weight of Thymosin beta-4?","text":"The average molecular weight of Thymosin beta-4 (TB4) listed on Costides is 4963 Da.","words":14},{"id":"faq-thymosin-beta-4-1","type":"faq","heading":"What is Thymosin beta-4?","text":"Thymosin beta-4 (timbetasin; CAS 77591-33-4) is the 43-residue N-acetyl protein (average MW 4963). It is not Costides SKU TB5. TB-500 (SKU TB5) is the synthetic N-acetyl heptapeptide Ac-LKKTETQ (CAS 885340-08-9; average MW 889.0), corresponding to residues 17–23 of thymosin beta-4. Research use only; not for human or veterinary use. Research Use Only. Not for human or veterinary use.","words":58},{"id":"faq-thymosin-beta-4-2","type":"faq","heading":"What is the CAS number of Thymosin beta-4?","text":"The CAS number of Thymosin beta-4 (TB4) is 77591-33-4. Formula and molecular weight appear in the identity table when retrieved.","words":20},{"id":"faq-thymosin-beta-4-3","type":"faq","heading":"Is Thymosin beta-4 for human use?","text":"No. Thymosin beta-4 (TB4) pages on Costides are Research Use Only reference materials. They are not medical advice and do not describe administration or dosing.","words":25},{"id":"faq-thymosin-beta-4-4","type":"faq","heading":"What is the molecular weight of Thymosin beta-4?","text":"The average molecular weight of Thymosin beta-4 (TB4) listed on Costides is 4963 Da.","words":14},{"id":"faq-thymosin-beta-4-5","type":"faq","heading":"Can I buy Thymosin beta-4 from Costides?","text":"No. Costides does not sell the 43-residue protein timbetasin (CAS 77591-33-4). SKU TB5 is TB-500, the 7-aa fragment Ac-LKKTETQ (CAS 885340-08-9). Research use only; not for human or veterinary use.","words":30},{"id":"faq-thymosin-beta-4-6","type":"faq","heading":"Where does identity data for Thymosin beta-4 come from?","text":"Costides indexes registry and bibliographic sources (PubChem, CAS Common Chemistry, PubMed permalinks) when available. Outcome or efficacy claims are not restated on this page.","words":24},{"id":"cite-thymosin-beta-4-1","type":"citation","heading":"PubChem CID 45382195","text":"PubChem CID 45382195. https://pubchem.ncbi.nlm.nih.gov/compound/45382195","words":4},{"id":"cite-thymosin-beta-4-2","type":"citation","heading":"CAS Common Chemistry 77591-33-4","text":"CAS Common Chemistry 77591-33-4. https://commonchemistry.cas.org/detail?cas_rn=77591-33-4","words":5},{"id":"cite-thymosin-beta-4-3","type":"citation","heading":"Dysregulation of circulating damage-associated molecular patterns in diabetic foot syndrome.","text":"Dysregulation of circulating damage-associated molecular patterns in diabetic foot syndrome.. PMID 42440461. https://pubmed.ncbi.nlm.nih.gov/42440461/","words":13},{"id":"cite-thymosin-beta-4-4","type":"citation","heading":"DOI for PMID 42440461","text":"DOI for PMID 42440461. PMID 42440461. https://doi.org/10.3389/fimmu.2026.1849387","words":7},{"id":"cite-thymosin-beta-4-5","type":"citation","heading":"Understanding the effects of ciprofloxacin on corneal epithelial cells: a study using electric cell-substrate impedance sensing (ECIS) technology.","text":"Understanding the effects of ciprofloxacin on corneal epithelial cells: a study using electric cell-substrate impedance sensing (ECIS) technology.. PMID 42431294. https://pubmed.ncbi.nlm.nih.gov/42431294/","words":21},{"id":"cite-thymosin-beta-4-6","type":"citation","heading":"DOI for PMID 42431294","text":"DOI for PMID 42431294. PMID 42431294. https://doi.org/10.1016/j.exer.2026.111162","words":7}],"faqs":[{"question":"What is Thymosin beta-4?","answer":"Thymosin beta-4 (timbetasin; CAS 77591-33-4) is the 43-residue N-acetyl protein (average MW 4963). It is not Costides SKU TB5. TB-500 (SKU TB5) is the synthetic N-acetyl heptapeptide Ac-LKKTETQ (CAS 885340-08-9; average MW 889.0), corresponding to residues 17–23 of thymosin beta-4. Research use only; not for human or veterinary use. Research Use Only. Not for human or veterinary use."},{"question":"What is the CAS number of Thymosin beta-4?","answer":"The CAS number of Thymosin beta-4 (TB4) is 77591-33-4. Formula and molecular weight appear in the identity table when retrieved."},{"question":"Is Thymosin beta-4 for human use?","answer":"No. Thymosin beta-4 (TB4) pages on Costides are Research Use Only reference materials. They are not medical advice and do not describe administration or dosing."},{"question":"What is the molecular weight of Thymosin beta-4?","answer":"The average molecular weight of Thymosin beta-4 (TB4) listed on Costides is 4963 Da."},{"question":"Can I buy Thymosin beta-4 from Costides?","answer":"No. Costides does not sell the 43-residue protein timbetasin (CAS 77591-33-4). SKU TB5 is TB-500, the 7-aa fragment Ac-LKKTETQ (CAS 885340-08-9). Research use only; not for human or veterinary use."},{"question":"Where does identity data for Thymosin beta-4 come from?","answer":"Costides indexes registry and bibliographic sources (PubChem, CAS Common Chemistry, PubMed permalinks) when available. Outcome or efficacy claims are not restated on this page."}],"links":[{"rel":"canonical","href":"https://costides.us/us/research/thymosin-beta-4"},{"rel":"rag","href":"https://costides.us/api/rag/compound/thymosin-beta-4"},{"rel":"llms","href":"https://costides.us/llms.txt"}]}