Thymosin Alpha-1
Immune-modulating peptide with decades of clinical use in chronic infection and cancer-adjunct settings.
Thymosin Alpha-1 (Thymosin Alpha-1 (Tα1)). Immune-modulating peptide with decades of clinical use in chronic infection and cancer-adjunct settings. Typical community dosing: 1.6 mg SC, 2× per week (600 mcg–3 mg ranges reported). Regulatory status: FDA orphan-drug / clinical-use status in certain settings.
28 residues· First described 1972
N-terminally acetylated
Overview
Thymosin Alpha-1 (Tα1) is a synthetic analog of a peptide naturally produced by the thymus gland. It has decades of clinical use, particularly in chronic hepatitis and as a cancer-treatment adjunct - it's approved for specific indications in 35+ countries outside the US. Under the 2026 reclassification, it's now a Category 1 peptide available via 503A compounding pharmacies.
The primary mechanism is T-cell maturation support. Tα1 helps the thymus convert immature lymphocytes into functional T-cells, restoring immune function in contexts where it's depleted (chronic infection, aging, stress, cancer therapy). This makes it one of the most clinically validated peptides in the immune category.
In optimization use, it's typically cycled for immune resilience - post-illness recovery, chronic low-grade infection concerns (EBV, CMV, Lyme), or preventative support in high-stress periods.
Mechanism of Action
Tα1 stimulates the maturation of bone-marrow lymphocytes into functional T-cells, enhances NK cell activity, and modulates cytokine signaling to rebalance Th1/Th2 response. In chronic-infection contexts, it supports the Th1 (cellular) arm that's often depleted.
Community Usage Patterns
1.6 mg SC, 2× per week is the most common protocol. Some immune-focused protocols run 600 mcg daily or 3 mg twice-weekly. Cycles typically 12–24 weeks. Common combos: with peptides for chronic infection workups, or post-illness for recovery support. Effects are often subjective (fewer illnesses, faster recovery) rather than lab-visible, but hs-CRP and NK cell panels can show changes.
Education only - not medical advice. Any protocol change should involve your licensed provider.
Biomarkers to Track
When running Thymosin Alpha-1, these are the biomarkers most commonly tracked to assess response and safety:
Blood Work Checklist
Before starting Thymosin Alpha-1, baseline the right panel. The Peptide Blood Work Checklist covers the full baseline panel, what to add for Thymosin Alpha-1's class, and when to retest.
See the peptide blood work checklist →Reconstitution Calculator
Free calculator for Thymosin Alpha-1 reconstitution math - vial size, BAC water volume, and exact syringe units.
Open Thymosin Alpha-1 calculator →Side Effects & Monitoring
What Thymosin Alpha-1 side effects are commonly reported, when they appear, the red flags worth a provider call, and the biomarkers that catch issues early.
Thymosin Alpha-1 side effects & what to track →Results & What to Track
What Thymosin Alpha-1 results actually look like in the data - the markers to measure, when they tend to move, and how to tell a real result from placebo.
Thymosin Alpha-1 results & how to measure them →Related Peptides
Stacks That Include Thymosin Alpha-1
Conditions Thymosin Alpha-1 is Commonly Researched For
Frequently Asked Questions
What is Thymosin Alpha-1?
Thymosin Alpha-1 (Tα1) is a synthetic analog of a peptide naturally produced by the thymus gland. It has decades of clinical use, particularly in chronic hepatitis and as a cancer-treatment adjunct - it's approved for specific indications in 35+ countries outside the US. Under the 2026 reclassification, it's now a Category 1 peptide available via 503A compounding pharmacies.
How does Thymosin Alpha-1 work?
Tα1 stimulates the maturation of bone-marrow lymphocytes into functional T-cells, enhances NK cell activity, and modulates cytokine signaling to rebalance Th1/Th2 response. In chronic-infection contexts, it supports the Th1 (cellular) arm that's often depleted.
What is the typical dosing for Thymosin Alpha-1?
1.6 mg SC, 2× per week (600 mcg–3 mg ranges reported)
What biomarkers should I track on Thymosin Alpha-1?
Common biomarkers tracked on Thymosin Alpha-1 protocols: CBC with differential, hs-CRP, NK cell activity (specialized), Lymphocyte subsets.
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Start tracking →This page is informational and does not constitute medical advice. MyProtocolStack is a tracking and education platform. Work with a licensed provider before starting, changing, or stopping any protocol.