FDA
No application listedNo application naming thymalfasin or thymosin alpha as an active ingredient is listed in Drugs@FDA. Checked 2026-10-05; the control lookup (semaglutide) returned 6 applications.
Drugs@FDA via openFDAThymosin α1: chemistry, literature and regulatory status
Research-use information. This page summarises published literature and regulator records. It is not guidance for use, not medical advice, and not a statement that any material is suitable for use in people or animals.
What is Thymosin α1?
Thymosin alpha 1 is a 28-residue N-acetylated peptide first described and characterised from calf thymus in 1977. Cell-culture work examines its effects on dendritic cells and toll-like receptor signalling. It is supplied here as a research material for laboratory use only.
What are the chemical facts for Thymosin α1?
- Name
- Thymosin α1
- Also written
- Thymalfasin
- Sequence
- Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN
- Length
- 28 residues
- Molecular formula
C129H215N33O55(matches the formula computed from the sequence)- Average molecular weight
- 3108.3 g/mol
- CAS number
62304-98-7(confirmed in PubChem)- PubChem
- CID 16130571
Chemistry checked against PubChem on 2026-10-05. Where the formula can be computed from the listed sequence, it was, and the two routes agree.
How does the literature describe the mechanism of Thymosin α1?
- Reviews describe effects on T cells, dendritic cells and cytokine production, and recombinant production methods.[3],[4]
- Human monocyte-derived dendritic cells were exposed to toll-like receptor agonists in the presence of thymosin alpha 1.[2]
- Dendritic cells and the immune synapse were examined in a cell culture model of human cytomegalovirus infection.[1]
Receptor and pathway background: Thymosin peptides.
What has published research on Thymosin α1 looked at?
4 studies are cited for Thymosin α1. Each is labelled by design below, and each entry says what the paper measured.
- 2 in vitro
- 2 review
PubMed returns 954 records for the search terms published on the method page (143 of them with a review publication type, 94 with a clinical-trial publication type), checked 5 October 2026. ClinicalTrials.gov lists 64 registered studies whose intervention matches the name (62 interventional), checked 5 October 2026.
Studies are listed by what they measured. Papers whose titles state an amount or schedule, or describe a clinical outcome of an approved medicine, are not listed. This is a wording rule, not a quality filter; see the method page.
What is the regulatory status of Thymosin α1?
EMA
No centrally authorised medicine listedNo centrally authorised procedure in the EMA medicines database (checked 5 October 2026) names thymalfasin or thymosin alpha as an active substance. National authorisations are not in this dataset.
EMA medicines dataMHRA
No product document foundNo SmPC, PIL or PAR document in MHRA Products matches the exact name "thymalfasin". Checked 2026-10-05; the control lookup (semaglutide) returned 271 documents.
MHRA ProductsWADA
Not namedThe WADA 2026 Prohibited List, in force 1 January 2026 does not name this substance. The list names substances by example, so this is not a statement that it is permitted in sport.
WADA Prohibited List 2026A regulator record is information about a database entry. It is not advice and not a statement that any use is lawful or unlawful in any country. How regulators approach research peptides.
Data dates: regulatory records 2026-10-05; WADA list 2026-10-05.
Which studies are cited for Thymosin α1?
[1] Espinar-Buitrago MS, Vazquez-Alejo E, Magro-Lopez E, Tarancon-Diez L, Leal M, Muñoz-Fernandez MA. Immune modulation via dendritic cells by the effect of Thymosin-alpha-1 on immune synapse in HCMV infection. Int Immunopharmacol. 2023;125:111103.
Examined thymosin alpha 1 effects on dendritic cells and the immune synapse in a cell culture model of human cytomegalovirus infection.
[2] Giacomini E, Severa M, Cruciani M, Etna MP, Rizzo F, Pardini M, et al.. Dual effect of Thymosin α 1 on human monocyte-derived dendritic cell in vitro stimulated with viral and bacterial toll-like receptor agonists. Expert Opin Biol Ther. 2015;15 Suppl 1:S59-70.
Measured responses of human monocyte-derived dendritic cells to toll-like receptor agonists in the presence of thymosin alpha 1.
[3] Li J, Liu CH, Wang FS. Thymosin alpha 1: biological activities, applications and genetic engineering production. Peptides. 2010;31:2151-8.
Review of thymosin alpha 1 effects on T cells, dendritic cells and cytokines, and of recombinant production methods.
[4] Garaci E, Favalli C, Pica F, Sinibaldi Vallebona P, Palamara AT, Matteucci C, et al.. Thymosin alpha 1: from bench to bedside. Ann N Y Acad Sci. 2007;1112:225-34.
Review of preclinical tumour models and the development path of thymosin alpha 1.
Data dates: citations read from PubMed 2026-10-05.
Where else in the research library is Thymosin α1 covered?
Who wrote this page and how is it checked?
Peptency editorial team, last reviewed 5 October 2026. Citations are read back from PubMed, chemistry is checked against PubChem, and regulator records are read from each regulator's own database on the dates shown. The method page lists every source, search term and rule. Corrections are welcome through the contact details on the About page.