Thymosin Alpha-1
Research Overview · Mechanism of Action · Reconstitution Guide
Overview
Thymosin Alpha-1 (Tα1) is a 28-amino acid N-terminally acetylated peptide originally isolated from thymosin fraction 5 of bovine thymus by Allan Goldstein in 1977. It is the most biologically active component of thymosin fraction 5 and has been approved in over 35 countries for treatment of hepatitis B, hepatitis C, and as an adjuvant in cancer immunotherapy. Tα1 is a potent immunomodulator that acts primarily on T-cell maturation, dendritic cell activation, and innate immune signaling.
Mechanism of Action
Thymosin Alpha-1 signals through toll-like receptors (TLR2, TLR9) on dendritic cells and macrophages, activating MyD88-dependent NF-κB and MAPK pathways to upregulate pro-inflammatory cytokines (IL-12, IFN-α) and co-stimulatory molecules. It promotes T-cell maturation in the thymus and enhances Th1 polarization, shifting immune responses toward cell-mediated immunity. Tα1 also upregulates MHC class I expression on tumor cells, enhancing cytotoxic T-lymphocyte recognition. In immunocompromised models, it restores T-cell counts and functional activity.
Key Studies & References
Goldstein AL et al. (1977). Thymosin alpha one: isolation and sequence analysis of an immunologically active thymic polypeptide. Proc Natl Acad Sci 74:725–729.
Garaci E et al. (2012). Thymosin α1 in the treatment of cancer: from basic research to clinical application. Int J Immunopharmacol 12:309–315.
Liu F et al. (2020). Thymosin Alpha-1 (Tα1) Reduces the Mortality of Severe COVID-19 by Restoration of Lymphocytopenia and Reversion of Exhausted T Cells. Clin Infect Dis 71:2150–2157.
Bacteriostatic Water Reconstitution Guide
Research Use Only — The following reconstitution information is provided for in vitro laboratory research purposes only. Not for human or veterinary use.
Recommended Solvent
Bacteriostatic water (0.9% benzyl alcohol) or sterile water for injection
Standard Volume
Add 1 mL bacteriostatic water to a 1.6 mg vial to yield a 1600 mcg/mL solution.
Working Concentration
1600 mcg/mL standard (matching the commercially approved Zadaxin formulation).
Storage (Reconstituted)
Reconstituted: 2–8°C, use within 24 hours if sterile water used; 28 days if bacteriostatic water used. Lyophilized: -20°C.
Stability Window
Use promptly after reconstitution with sterile water. Bacteriostatic water extends usability to 28 days.
Technique
Inject solvent slowly along the vial wall. Swirl gently until dissolved. Clear, colorless solution.
Notes
The approved clinical formulation (Zadaxin) uses 1.6 mg/vial. This is a useful reference point for research protocol design.
Research Dosing Reference
The following dosing information is derived from published clinical and preclinical research literature and is provided for reference purposes only.
Clinical / Human Research Range
Approved clinical dose: 1.6 mg subcutaneous twice weekly (hepatitis protocols). Oncology adjuvant: 1.6–3.2 mg twice weekly.
Preclinical Models
Rodent studies: 100 mcg/kg to 1 mg/kg subcutaneous, daily to twice weekly.
Calculation Example
For a 1600 mcg/mL solution: a 1.6 mg research dose = 1.0 mL.