Research/Compounds/Thymosin Alpha-1
Category 1SubQ · Immune

Thymosin Alpha-1

Ta1 — Immune System Modulator

Half-life
~2 hours
Route
SubQ
Typical dose
1.5 mg, 2x/week
Reconstitutable
Yes

What is Thymosin Alpha-1?

Thymosin Alpha-1 (Ta1) is a 28-amino acid peptide naturally produced by the thymus gland and the active ingredient in Zadaxin — approved in over 35 countries for hepatitis B, hepatitis C, and cancer immunotherapy. It has one of the strongest clinical evidence bases of any immunomodulatory peptide.

Thymosin Alpha-1 modulates innate and adaptive immunity by activating dendritic cells, stimulating T-cell differentiation and proliferation, promoting Th1 cytokine production (IFN-gamma, IL-2), and enhancing natural killer cell activity. It normalizes dysregulated immune responses in both directions — boosting underactive immunity and potentially modulating overactive responses.

Research Evidence

GoldHepatitis B & C Treatment

Multiple Phase 3 clinical trials support regulatory approval as Zadaxin in 35+ countries. Strongest human evidence base of any commonly used immunomodulatory peptide.

SilverCancer Immunotherapy Adjuvant

Clinical trials show improved outcomes when Ta1 is added to standard chemotherapy or immunotherapy for multiple cancer types.

SilverPost-COVID & Immune Recovery

Chinese studies during COVID-19 reported improved outcomes in critically ill patients treated with Ta1. Increasing use for immune recovery.

Evidence grades: Gold = RCT human data · Silver = multiple animal studies, consistent · Bronze = limited or preliminary

Dosing Protocols

Standard dose
1.5 mg SubQ
Most clinical trials use 1.6mg (commercial Zadaxin formulation). Community protocols use 1-1.5mg.
Frequency
2x weekly
Monday/Thursday or similar twice-weekly protocol. More frequent dosing (daily) for acute illness.
Cycle length
6–12 months (chronic)
Hepatitis trials ran 6-12 months. Short-term immune support protocols run 4-8 weeks.

Reconstitution Guide

Vial SizeBAC WaterConcentrationTarget draw
3 mg2 ml1.5 mg/ml1.5mg = 100 units
10 mg6.7 ml1.5 mg/ml1.5mg = 100 units
Calculate your exact protocol →

Frequently Asked Questions

Is Thymosin Alpha-1 FDA approved?

As Zadaxin, it is approved in over 35 countries for hepatitis B, hepatitis C, and cancer immunotherapy. It is not FDA-approved in the US but is available through compounding pharmacies as a Category 1 bulk substance.

Is Thymosin Alpha-1 the same as TB-500 (Thymosin Beta-4)?

No. Thymosin Alpha-1 and Thymosin Beta-4 are entirely different peptides. Ta1 is primarily immunomodulatory — it acts on immune cells. TB-500 acts on actin regulation and tissue repair. They are sometimes stacked together in comprehensive protocols.

References

  1. [1]Goldstein AL, Goldstein AL. From lab to bedside: emerging clinical applications of thymosin alpha 1. Expert Opin Biol Ther. 2009;9(5):593-608.
  2. [2]Liu F, Li Y, Feng Y, et al. Thymosin alpha-1 reduces the mortality of severe COVID-19 by restoration of lymphocytopenia and reversion of exhausted T cells. Clin Infect Dis. 2020;71(16):2150-2157.
Disclaimer: This profile is for informational and research purposes only. Not medical advice. Always consult a licensed healthcare provider before using any compound.

This profile was prepared using AI-assisted research synthesis. Citations are provided where applicable — verify with primary sources before clinical application.

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