Thymosin Alpha-1
Category 1Also known as: Tα1, Zadaxin
Immune SupportLast reviewed: April 28, 2026
A thymic peptide that plays a central role in immune system regulation. Approved as a drug in over 35 countries (though not in the US) for hepatitis B and C treatment and as an immune booster.
Mechanism of Action
Enhances T-cell function, promotes dendritic cell maturation, and modulates cytokine production. Acts as an immune system regulator rather than a simple stimulant, helping to balance immune responses.
Common Uses
- Immune system support
- Chronic infection management
- Cancer adjunct therapy (in some countries)
- Post-illness recovery
- Autoimmune condition management
Known Risks
- Generally well-tolerated in clinical use
- Injection site reactions
- Rare allergic reactions
- May interact with immunosuppressive drugs
Regulatory Status
Reclassified to Category 1 in February 2026 as part of the HHS announcement restoring compounding access. Not affected by the April 15, 2026 Category 2 removal action. Approved as Zadaxin in 35+ countries but not FDA-approved in the US. Available through licensed 503A compounding pharmacies with a physician prescription.
Common Protocols
Protocol information is for educational reference only. Dosing varies significantly by individual, condition, and physician guidance. Always work with a licensed healthcare provider.
Subcutaneous injection
Typical Dose
1.6 mg
Frequency
2x per week
Cycle Length
6–12 weeks
Standard clinical dose used in approved international formulations (Zadaxin). Often used during illness recovery or as an immune support protocol. Reconstitute with bacteriostatic water.
Related Compounds
Research References
Related Articles
This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy. Data is compiled from published research and regulatory sources and may not reflect the most recent developments.