FDA-approved·Thymic immune-modulating peptide

Thymosin Alpha-1

aka TA-1, Zadaxin

Education only. Many compounds discussed are research chemicals not approved for human use in the US. This is not medical advice — consult a licensed physician.

What it is

A 28-amino acid peptide naturally produced by the thymus gland. FDA-approved as Zadaxin for hepatitis B/C and other immune conditions in 35+ countries (not US-approved but available via compounding). Acts as an "immune thermostat" — boosts immune response when underactive, calms it when overactive.

How it works

Activates and matures T-cells (CD4 and CD8), modulates cytokine production, enhances natural killer cell activity. Restores balance to dysregulated immune systems without overstimulation.

What the research says

Decades of clinical trial data for hepatitis B/C treatment. Multiple studies show benefit in chronic infection, post-surgical recovery, and immune dysregulation. Strongest safety profile of any longevity-tier peptide.

Sources: PubMed: Thymosin alpha 1 · Zadaxin clinical data

Common dosing ranges

Range: 0.5–1.6 mg per dose
Frequency: Daily SubQ, often 2x/week long-term
Duration: 4–6 week cycles or ongoing for chronic conditions

Sources: PubMed

Administration

SubQ · IM

Half-life

~2 hours

Side effects

Common

Injection site reactions (mild)
Generally well-tolerated

Serious / theoretical

Contraindicated in active autoimmune disease
Contraindicated in active cancer (immune surveillance accelerator)

Sources: PubMed

Notes

Bachmeyer includes TA-1 in his "4 Forever Peptides" longevity scaffold. One of the few peptides with FDA approval (in other countries) and decades of human safety data.