What Is Thymosin Alpha-1?
Thymosin Alpha-1 (Ta1) is a 28-amino-acid peptide naturally produced by the thymus gland. It plays a central role in immune system modulation, particularly in T-cell maturation and function. Ta1 is approved as a pharmaceutical drug in over 35 countries (marketed as Zadaxin), primarily for hepatitis B and C treatment and as an immune adjuvant — but it has never been FDA-approved in the United States.
Thymosin Alpha-1 is one of the most clinically validated peptides in the reclassification pipeline — it has real Phase III trial data and decades of clinical use in Asia, Europe, and Latin America.
Quick Facts
| Property | Detail |
|---|---|
| Amino Acids | 28 |
| Molecular Weight | ~3,108 Da |
| Origin | Thymus gland extract (synthetic for commercial use) |
| Regulatory Status | Expected Category 1 reclassification |
| Prescription Required | Yes (pharmacy); No (research vendor) |
| Approved Outside US | Yes — 35+ countries as Zadaxin |
Research Areas of Interest
- Immune modulation — enhances T-cell function, dendritic cell maturation, and natural killer cell activity
- Chronic viral infections — studied extensively for hepatitis B and C; approved for this use in multiple countries
- Cancer immunotherapy adjunct — investigated as a complement to chemotherapy and immunotherapy regimens
- Vaccine enhancement — research suggests it may improve antibody response in immunocompromised individuals
- Sepsis and critical illness — emerging research on outcomes in critically ill patients
How It's Sold
| Source | Form | Prescription? | Typical Cost |
|---|---|---|---|
| Research Vendors | Lyophilized powder (5mg vial) | No | $40-90/vial |
| Compounding Pharmacy | Injectable (subcutaneous) | Yes | $150-400+/month |
What to Look For on the COA
- HPLC purity — minimum 95% research grade, 98%+ preferred
- Mass spectrometry — confirmed molecular weight of ~3,108 Da
- Endotoxin testing — critical for injectable use
- Amino acid analysis — confirms full 28-amino-acid sequence
- Batch/lot number — must match product label
Ta1 is a larger peptide (28 amino acids) than many popular compounds, making synthesis more complex and quality more variable. Third-party testing is especially important.
Storage Guide
- Lyophilized (powder): Store at -20°C for long-term stability; 2-8°C for short-term
- Reconstituted: Refrigerate at 2-8°C. Use within 14-21 days
- All forms: Protect from light. Avoid repeated freeze/thaw cycles
Key Sourcing Tips
- Always request and verify the COA — batch numbers must match your product label
- Ta1 is a longer peptide (28aa), making it more expensive to synthesize correctly — be skeptical of unusually cheap sources
- Compare purity and mass spec data across vendors before purchasing
- For personal use: work with a licensed provider and compounding pharmacy
- Avoid any source making specific disease treatment claims — Ta1 is not FDA-approved in the US