Research Compendium/Thymosin Alpha-1
Immune ModulationResearch OnlyNot For Human Consumption

Thymosin Alpha-1

Tα1 · Thymalfasin · Zadaxin

Thymic peptide approved in 37 countries - bidirectional immune modulator with hepatitis, oncology, and sepsis research applications.

MECHANISM OF ACTION

Thymosin Alpha-1 (Tα1) is a 28-amino acid peptide originally isolated from thymic tissue. Acts as an immunomodulator via dendritic cell maturation, Th1 cytokine polarisation (IFN-γ, IL-2), and regulatory T-cell induction. Exhibits bidirectional immune modulation - potentiates responses in immunodeficient states while inducing tolerance in autoimmune models. TLR9 activation and PI3K/Akt pathway modulation identified as key downstream targets. One of the most clinically studied peptides globally with approval in 37 countries.

RESEARCH APPLICATIONS

  • Viral hepatitis B and C immunotherapy (approved)
  • Adjuvant immunotherapy in oncology
  • Sepsis and critical illness immune reconstitution
  • COVID-19 cytokine dysregulation
  • Vaccine adjuvant research

RESEARCH HIGHLIGHTS

Hepatitis B Seroconversion

2006

Meta-analysis of 9 RCTs (n=726) showed higher HBeAg seroconversion with Tα1 vs. IFN-α monotherapy, with superior tolerability.

Ref: Chan et al., Antiviral Therapy

COVID-19 Mortality Reduction

2022

Retrospective cohort (n=3,240): Tα1 treatment associated with reduced 28-day mortality (HR 0.58, p<0.001) and shorter ICU stay.

Ref: Liu et al., J Infect Dis

RESEARCH PROTOCOL NOTES

Approved clinical dose1.6 mg SC twice weekly (Zadaxin)
RouteSC only - oral bioavailability <1%

Chemical Identity

Molecular FormulaC129H215N33O55S2
Molecular Weight3108.5 g/mol
CAS Number62304-98-7
Half-Life (t½)~2 hours after SC
SolubilityHighly soluble in water

Storage & Stability

Lyophilised: 2–8°C, 24 months. Reconstituted: use within 6 hours - no preservative in approved formulation.

Regulatory Status

Approved in 37+ countries as Zadaxin. Not FDA approved. SA: importable via named patient provisions. Not WADA prohibited.