Thymosin Alpha-1
Dosage Protocol
Thymosin Alpha-1 (Tα1) is a 28-amino acid peptide derived from prothymosin alpha in the thymus. It is FDA-approved as Zadaxin® in 35+ countries for the treatment of hepatitis B, hepatitis C, and as an adjunct in cancer immunotherapy. It modulates innate and adaptive immunity by promoting dendritic cell maturation, T-cell differentiation, and NK cell activation.
What is Thymosin Alpha-1?
Thymosin Alpha-1 was first isolated from bovine thymic extract by Allan Goldstein's group at George Washington University in 1977. It was identified as the primary biologically active component of Thymosin Fraction 5 — a thymic peptide extract used in early immunotherapy research. The synthetic version (Tα1) has been extensively studied and approved internationally as Zadaxin®.
Tα1 acts primarily on toll-like receptors (TLR2, TLR9) and MHC class II pathways to mature dendritic cells, shift T-cell differentiation toward Th1 and regulatory T-cell phenotypes, and enhance NK cell cytotoxicity. Clinical applications include hepatitis B/C treatment, cancer immunotherapy adjuvant, and COVID-19 immune support — where Chinese clinical data showed significantly improved outcomes when added to standard care.
Dosing Schedule
Parameters documented in published preclinical and clinical research.
| Phase | Dose | Frequency | Duration | Notes |
|---|---|---|---|---|
| Standard | 1.6 mg | 2× weekly SubQ | 16–52 weeks | Zadaxin-approved dose. Single-dose vial — use entire contents immediately after reconstitution. |
| Intensive | 1.6 mg | Daily | 2–4 weeks | Daily dosing used in some cancer and COVID-19 protocols. Reconstitute fresh each time. |
| Longevity | 1.6 mg | 1–2× weekly | 12 weeks, 1–2× yearly | Off-label longevity and immune optimization protocol. |
| Immune prep | 1.6 mg | 5 days on / 2 off | 4 weeks | Short cycle for immune priming before high-stress periods. |
Safety & Side Effects
Academic References
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[1]
Goldstein AL, et al. (1977). Purification and biological activity of thymosin, a hormone of the thymus gland. Proc Natl Acad Sci USA. 69(6):1800–3. PubMed ↗
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[2]
Tuthill CW, et al. (2006). Thymosin alpha 1 as a targeted therapy for immune restoration. Ann N Y Acad Sci. 1112:1–10. PubMed ↗
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[3]
Ji P, et al. (2020). Thymosin alpha 1 as an immunomodulatory and anti-inflammatory agent in severe COVID-19. Clin Infect Dis. 72(4):686–9. PubMed ↗
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[4]
Ershler WB, et al. (2003). Clinical applications of thymosin alpha-1: a review. Oncology. 17(9 Suppl 8):22–6. PubMed ↗