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Peptide Protocol

Thymosin Alpha-1: the thymic master switch — immune precision.

28-amino acid thymic peptide. FDA-approved internationally for hepatitis and cancer immunotherapy. Activates T-cell and dendritic cell function.

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Immune Peptide Research Use Only

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.

1.6 mg
Standard Dose
12–52 weeks
Cycle
SubQ
Route
2× weekly
Frequency
Overview

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.

TLR Activation
Activates TLR2 and TLR9 signaling pathways on dendritic cells and macrophages, promoting maturation and pro-inflammatory cytokine production.
T-Cell Differentiation
Promotes Th1 differentiation and regulatory T-cell development, restoring immune balance in immunocompromised or dysregulated states.
NK Cell Enhancement
Increases natural killer cell cytotoxicity against viral-infected and tumor cells, supporting both innate and adaptive anti-tumor immunity.
Antiviral Activity
Demonstrated antiviral effects against HBV, HCV, and SARS-CoV-2 through immune-mediated mechanisms rather than direct antiviral action.
Dosing Protocol

Dosing Schedule

Parameters documented in published preclinical and clinical research.

Research use only. The following documents parameters from published preclinical and clinical research. Not medical advice. Not for human consumption. Consult a licensed healthcare professional before any use.
PhaseDoseFrequencyDurationNotes
Standard1.6 mg2× weekly SubQ16–52 weeksZadaxin-approved dose. Single-dose vial — use entire contents immediately after reconstitution.
Intensive1.6 mgDaily2–4 weeksDaily dosing used in some cancer and COVID-19 protocols. Reconstitute fresh each time.
Longevity1.6 mg1–2× weekly12 weeks, 1–2× yearlyOff-label longevity and immune optimization protocol.
Immune prep1.6 mg5 days on / 2 off4 weeksShort cycle for immune priming before high-stress periods.
Safety Profile

Safety & Side Effects

Generally Well Tolerated
FDA-approved (Zadaxin) in 35+ countries for hepatitis and cancer adjuvant
Extensive clinical safety data from formal trials
Endogenous peptide — well tolerated across decades of use
No significant immunosuppression or autoimmune risk reported
Potential Concerns
Not FDA-approved in the US — available as research peptide
Mild injection site reactions possible
May be contraindicated with certain immunosuppressive therapies
Long-term continuous use protocols not well studied
Research use onlyThis page is an educational reference. None of this constitutes medical advice. Consult a qualified professional before any use. All compounds are for research purposes only.
Evidence Base

Academic References

  1. [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 ↗
  2. [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 ↗
  3. [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 ↗
  4. [4]
    Ershler WB, et al. (2003). Clinical applications of thymosin alpha-1: a review. Oncology. 17(9 Suppl 8):22–6. PubMed ↗
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