Research Applications
Chronic Hepatitis B and C
Tα1 (Zadaxin) is approved in over 35 countries for chronic hepatitis B treatment, typically combined with interferon or nucleos(t)ide analogs. Clinical trials show enhanced viral clearance rates and improved seroconversion. For hepatitis C, it enhances interferon-based therapy response rates.
Cancer Immunotherapy Adjuvant
Tα1 is used as an immune adjuvant alongside chemotherapy, radiation, and checkpoint inhibitor therapy. Clinical studies in hepatocellular carcinoma, melanoma, non-small cell lung cancer, and breast cancer demonstrate improved immune reconstitution, enhanced anti-tumor immunity, and improved survival when combined with standard oncologic treatments.
Vaccine Enhancement
Tα1 is approved in several countries as a vaccine adjuvant, enhancing immune response to influenza, hepatitis B, and other vaccines. It is particularly effective in elderly and immunocompromised populations who normally have suboptimal vaccine responses.
Immunodeficiency States
Research demonstrates Tα1 restores immune function in HIV/AIDS (increases CD4+ counts), post-chemotherapy immunosuppression, transplant recipients, and age-related immunosenescence. It is used clinically as an immune restorative agent.
Sepsis and Critical Care
Clinical studies show Tα1 reduces mortality in severe sepsis by restoring immune function and preventing immunoparalysis. It enhances pathogen clearance and reduces secondary infection rates in ICU patients.
COVID-19 and Respiratory Infections
During the COVID-19 pandemic, Tα1 was used in Chinese treatment protocols based on its immunomodulatory properties. Observational studies suggested improved immune reconstitution and reduced mortality in critically ill patients with lymphopenia.
Mechanism of Action
Dendritic Cell Maturation
Tα1 acts on dendritic cells (DCs) through toll-like receptor 9 (TLR9) and intracellular signaling through MyD88 and IRF7. This promotes DC maturation, enhancing antigen presentation and the ability to prime naive T-cells. Mature DCs produce increased IL-12 and type I interferons, shifting immune responses toward Th1 (cell-mediated) dominance.
T-Cell Differentiation and Function
Tα1 promotes differentiation of immature T-cells (thymocytes) into mature, functional CD4+ helper T-cells and CD8+ cytotoxic T-cells. It upregulates T-cell receptor expression, enhances T-cell proliferative responses to antigens, and restores T-cell function in immunocompromised states. It also promotes Th1/Th2 balance by selectively enhancing Th1 responses.
Natural Killer Cell Activation
Tα1 enhances NK cell cytotoxicity through upregulation of NKG2D receptor expression and increased production of perforin and granzymes. This enhanced NK activity contributes to anti-viral and anti-tumor immune surveillance.
Toll-Like Receptor Modulation
Beyond TLR9, Tα1 modulates TLR2, TLR3, and TLR4 signaling on immune cells, enhancing pathogen recognition and innate immune responses. It acts as an "immune system trainer," improving the ability of immune cells to detect and respond to diverse threats.
Oxidative Stress Reduction in Immune Cells
Tα1 upregulates antioxidant enzyme expression (SOD, catalase, glutathione peroxidase) in immune cells, protecting them from oxidative damage that impairs function. This is particularly important in chronic infections and cancer, where oxidative stress contributes to immune exhaustion.
Biological Pathways
TLR9/MyD88/IRF7 Innate Immune Pathway
Tα1-TLR9 interaction activates the MyD88-dependent signaling cascade, leading to NF-κB and IRF7 activation. NF-κB drives pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6), while IRF7 induces type I interferons (IFN-α, IFN-β) — critical for antiviral defense.
JAK/STAT Immune Signaling
Cytokines induced by Tα1 (particularly IL-12 and IFN-γ) activate JAK/STAT signaling in T-cells and NK cells. STAT1 and STAT4 activation drives Th1 differentiation and cytotoxic T-cell function, while STAT3 balances inflammatory responses.
p38 MAPK Stress Response
Tα1 activates p38 MAPK in immune cells, enhancing their ability to respond to stress signals and pathogen-associated molecular patterns (PAMPs). p38 MAPK also drives expression of cytokines and chemokines that recruit additional immune cells to sites of infection.
IDO/Tryptophan Immune Regulation
Tα1 modulates indoleamine 2,3-dioxygenase (IDO) expression in DCs, balancing immune activation with tolerance. This is important for preventing autoimmune reactions while maintaining effective anti-pathogen and anti-tumor responses.
Dosage Information
Calculation Results
Syringe Fill Level (100u syringe)
Protocols
Thymosin Alpha-1 Immune ProtocolIntermediate🛡️Immune SupportMinimum 3 months
Immune modulating peptide for chronic illness, immune deficiency, and infection recovery.
Warning: Requires sustained use. Monitor immune markers.
Stability & Storage
Thymosin Alpha-1 (thymalfasin/Zadaxin) is commercially available as a lyophilized powder for injection in 1.6 mg and 3.2 mg vials. Store at controlled room temperature (15-25°C) for up to 3 years — the commercial product has exceptional room-temperature stability for a peptide.
The N-terminal acetylation of Tα1 (Ac-Ser) protects against aminopeptidase degradation, contributing to its stability. The peptide has no cysteine residues (no disulfide bonds to maintain) and minimal oxidation-prone residues, contributing to its robust stability profile.
For research-grade Tα1, store lyophilized powder at -20°C for long-term stability. Reconstitute with sterile water or bacteriostatic water. Store reconstituted solution at 2-8°C and use within 14 days. The in-vivo half-life is approximately 2 hours following subcutaneous injection.
Side Effects & Precautions
Excellent Safety Profile
Tα1 has one of the best-documented safety profiles among therapeutic peptides, with over 4,400 patients treated in controlled clinical trials. The overall adverse event rate is comparable to placebo across multiple studies.
Injection Site Reactions
Mild erythema, pain, or induration at injection sites is the most common adverse effect. These are transient and self-limiting.
Mild Flu-Like Symptoms
Occasional mild fever, fatigue, or myalgia may occur, particularly during the first few doses, as the immune system is activated. These symptoms are typically mild and resolve within 24 hours.
No Autoimmune Activation
Despite potent immune enhancement, Tα1 has not been associated with autoimmune disease exacerbation in clinical trials. Its balanced immunomodulatory mechanism (enhancing function without causing hyperactivation) provides an inherent safety margin.
No Hepatotoxicity
Tα1 has demonstrated hepatoprotective properties and does not cause liver enzyme elevations, even in patients with pre-existing liver disease.
No Significant Drug Interactions
No clinically meaningful drug interactions have been identified. Tα1 is used safely in combination with interferons, antivirals, chemotherapy agents, and other immunomodulators.
Research Use Only. This information is for educational and research purposes only. Not intended for medical advice or self-medication.
Regulatory Status
Thymosin Alpha-1 (thymalfasin, Zadaxin) is approved in over 35 countries for hepatitis B treatment and immune modulation. Major approvals include China, India, South Korea, Philippines, and several other Asian, South American, and European countries.
Tα1 is not FDA-approved for any indication, though it has received Orphan Drug designation for hepatocellular carcinoma and DiGeorge syndrome. Multiple IND applications have been filed, and clinical trials have been conducted in the United States.
The peptide is not on the WADA prohibited list. It is classified as a prescription medication in countries where it is approved and as a research compound in the United States.
Research Studies
Thymosin Alpha 1: A Comprehensive Review of the Literature
Dominari A, Hathaway D III, Pandya K, et al.
Thymalfasin (Thymosin Alpha 1) for Treatment of Hepatitis B
Iino S.
Thymosin Alpha 1 Activates Dendritic Cells through TLR9
Romani L, Bistoni F, Montagnoli C, et al.
Thymosin Alpha 1 in Cancer: From Bench to Bedside
Garaci E, Pica F, Serafino A, et al.
Thymosin Alpha-1 for Sepsis: A Systematic Review and Meta-Analysis
Li C, Bo L, Liu Q, Jin F.
