Thymosin Alpha-1
Ta1 · Zadaxin · Thymalfasin
Popular for:Immune modulation, T-cell function, hepatitis treatment
61
Registered Trials
49
Trial Publications
575
PubMed References
Approved
Evidence Level
Overview
Thymosin Alpha-1 (Ta1) is a 28-amino acid peptide naturally produced by the thymus gland that plays a crucial role in immune system regulation. The short version: people usually care about it for immune modulation, t-cell function, hepatitis treatment, but the strength of the evidence depends heavily on indication and study type.
Thymosin Alpha-1 (Ta1) is a 28-amino acid peptide naturally produced by the thymus gland that plays a crucial role in immune system regulation. It is approved as a pharmaceutical drug (Zadaxin) in over 30 countries for the treatment of hepatitis B, hepatitis C, and as an immune adjuvant.
Thymosin Alpha-1 is one of the most clinically validated peptides, with extensive human trial data. The thymus gland shrinks with age (thymic involution), and declining Ta1 levels are associated with age-related immune dysfunction. Exogenous Ta1 supplementation is studied for restoring T-cell function and immune surveillance.
Research Snapshot
What the evidence says
ApprovedThymosin Alpha-1 currently shows 61 registered trials from ClinicalTrials.gov, 49 PubMed trial publications (35 RCT-tagged), and 575 PubMed references matching the stored source query. Treat PubMed references as literature surface area, not a count of clinical trials.
Known vs uncertain
Known signals
- 61 registered trials are tracked from ClinicalTrials.gov intervention records.
- 49 PubMed clinical-trial publications are indexed.
- 35 PubMed randomized controlled trial publications are indexed.
- 575 PubMed references are tracked separately from trial counts and can include animal, in-vitro, review, mechanism, or clinical records.
Open questions
- Evidence strength may vary by indication, route, formulation, and population.
- Public anecdotes can highlight interest or concern but do not establish clinical efficacy.
- Regulatory status and compounding access can change independently from the research literature.
Mechanism of Action
Thymosin Alpha-1 enhances T-cell maturation, differentiation, and function by acting on toll-like receptors (TLR2, TLR9) in dendritic cells.
Key Research Benefits
Clinical Evidence Summary
Research Pipeline
International Regulatory Status
61
Registered Trials
49
Trial Publications
35
RCT Publications
575
PubMed References
Registered trials are ClinicalTrials.gov intervention records. Trial publications are PubMed records tagged as clinical trials or randomized controlled trials. PubMed references are broader source-query matches and can include animal studies, in-vitro work, reviews, mechanism papers, and trial publications.
61
Registered trials
49
Trial publications
35
RCT publications
575
PubMed references
76
Reviews
10
Meta-analyses
Registered trials source
Jun 1, 2026
Thymosin Alpha-1
Uses the exact compound name as a ClinicalTrials.gov intervention query.
View sourceApproved as Zadaxin in 30+ countries (not FDA-approved in US). Extensive human clinical trial data. FDA Category 2 status under review; potential Category 1 reinstatement.
Key PubMed References
575 PubMed references · showing top 25 by relevance
View all on PubMedThe efficacy and safety of thymosin alpha-1 combined with lenvatinib plus sintilimab in unresectable hepatocellular carcinoma: a retrospective study.
Yao S, Huang Q, Zou Y, et al. · Scientific reports · 2025
PMID: 40263352Aging and Thymosin Alpha-1.
Simonova MA, Ivanov I, Shoshina NS, et al. · International journal of molecular sciences · 2025
PMID: 41373628Phenotypic drug discovery: a case for thymosin alpha-1.
Garaci E, Paci M, Matteucci C, et al. · Frontiers in medicine · 2024
PMID: 38903817Enhanced Immunomodulatory Effects of Thymosin-Alpha-1 in Combination with Polyanionic Carbosilane Dendrimers against HCMV Infection.
Espinar-Buitrago MS, Magro-López E, Vázquez-Alejo E, et al. · International journal of molecular sciences · 2024
PMID: 38396631Comprehensive Review of the Safety and Efficacy of Thymosin Alpha 1 in Human Clinical Trials.
Dinetz E, Lee E · Alternative therapies in health and medicine · 2024
PMID: 38308608Anecdotes & Sentiment
This section summarizes what people are talking about in public sources. It can be useful for spotting questions, hype cycles, and recurring concerns, but it is separate from the evidence sections above.
No curated public-discussion themes are live for Thymosin Alpha-1 yet.
Side Effects & Safety
- Generally very well-tolerated in clinical trials - Injection site reactions - Rare cases of mild fever (immune activation) - Fatigue during initial use
Known Interactions
No curated interaction entry is live for Thymosin Alpha-1 yet.
Until the interaction table is fully populated, use the interaction checker and related peptides below to explore adjacent compounds and likely research pairings.
Comparison Pages
Comparison pages
AllNo comparison page is linked yet.
Frequently Asked Questions
Research Disclaimer
This page is for research and educational purposes only. The information presented is based on published scientific literature and does not constitute medical advice, diagnosis, or treatment recommendations. Regulatory status can vary by compound, formulation, indication, and jurisdiction. Check official labeling, registry records, and qualified professional guidance before making any health-related decision. The studies referenced are linked to their original PubMed sources for verification.