Scientific Reference

Thymosin Alpha 1

Evidence profile: Controlled human evidence

Thymosin Alpha 1 (Ta1/Thymalfasin/Zadaxin) is a synthetic 28-amino acid peptide identical to the naturally occurring thymic hormone. It has been extensively studied across numerous clinical trials and is approved in multiple countries for immune-related conditions. Ta1 demonstrates a strong safety profile while providing broad immunomodulatory effects. Injectable Ta1 exhibits high bioavailability and activates multiple immune pathways, including T-cell maturation, NK cell activation, and dendritic cell modulation, making it one of the most clinically validated immunomodulatory peptides available.

Mechanism of Action

Thymosin Alpha 1 activates toll-like receptor (TLR) pathways and enhances both innate and adaptive immunity. It promotes T-cell differentiation, increases NK cell cytotoxicity, and improves dendritic cell antigen presentation. Its structure mimics endogenous thymic hormone signaling, enabling physiological immune modulation without excessive activation.

Molecular Information

Type: Thymic hormone analog (immunomodulatory peptide)
Length: 28 amino acids
Molecular weight: 3108.3 g/mol
Molecular formula: C129H215N33O55
CAS: 62304-98-7

Published Research

Treatment with thymosin alpha-1 increases fertilizing capacity of sperm of infertile men: a multicenter trial
Naz RK et al. · Archives of andrology · 1995 · Clinical
PMID 8579476 — View on PubMed
Thymosin alpha 1 alleviates inflammation and prevents infection in patients with severe acute pancreatitis through immune regulation: a systematic review and meta-analysis
Tian Y et al. · Frontiers in immunology · 2025 · Review
PMID 40599771 — View on PubMed
Thymosin Alpha 1 Plus Routine Treatment for the Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis
Cao A et al. · Journal of the College of Physicians and Surgeons--Pakistan : JCPSP · 2024 · Review
PMID 39648386 — View on PubMed
Comprehensive Review of the Safety and Efficacy of Thymosin Alpha 1 in Human Clinical Trials
Dinetz E et al. · Alternative therapies in health and medicine · 2024 · Review
PMID 38308608 — View on PubMed
The efficacy of thymosin alpha-1 therapy in moderate to critical COVID-19 patients: a systematic review, meta-analysis, and meta-regression
Soeroto AY et al. · Inflammopharmacology · 2023 · Review
PMID 37845598 — View on PubMed