Comprehensive Clinical Evidence Review
30+ trials and over 11,000 human subjects confirmed consistent safety and efficacy in viral disease, autoimmune conditions, and oncology adjunctive use.
[3]A synthetic 28-amino-acid peptide identical to a naturally occurring thymic hormone, with one of the largest clinical evidence bases of any compounded immune peptide.
Marketed internationally as Zadaxin, TA-1 is approved in over 35 countries for chronic hepatitis B, hepatitis C adjunctive therapy, and immunocompromised patient support, with regulatory standing across multiple international health authorities.
At a glance
- Type
- Synthetic 28-amino-acid peptide identical to a naturally occurring thymic hormone
- What it does
- Promotes maturation of T-cells, enhances natural killer and dendritic cell activity, restores Th1 cytokine responses, improves antigen presentation
- Regulatory
- Marketed internationally as Zadaxin; approved in over 35 countries
- Route
- Subcutaneous
- Evidence base
- 30+ trials and over 11,000 human subjects
- Baseline labs
- CBC with differential and, where available, lymphocyte subsets
What the research supports
TA-1 has the strongest international clinical evidence base of any compounded immune peptide, with over 11,000 human subjects across 30+ trials.
Severe Acute Pancreatitis Meta-Analysis
TA-1 raised CD4+ T-cell percentages and the CD4/CD8 ratio, reduced extrapancreatic infection incidence, and lowered APACHE II severity scores in critically ill patients.
[2]Aging and Thymic Involution
TA-1 counteracts thymic involution and immunosenescence; fusion construct Refnot (TNF-alpha plus TA-1) emerging as research compound with immunomodulatory and antitumor activity.
[1]International Approval (Zadaxin)
Approved in 35+ countries for chronic hepatitis B, hepatitis C adjunctive therapy, and immunocompromised patient support with real regulatory standing.
Summary of key findings
Strongest International Evidence Base
Approved in 35+ countries; 11,000+ subject evidence base; real regulatory standing.
Two Equivalent Dosing Patterns
Compounded protocols typically run 1.5 mg SC 3x weekly; the internationally approved Zadaxin protocol is 1.6 mg SC 2x weekly.
Mild Flu-Like Sensation Expected
First 24 to 48 hours of a new course; expected response, not a side effect.
Sequences with Thymalin
Complementary mechanisms: thymic-derived broad bioregulation versus T-cell specific maturation.
Dosing guide
From published protocols. Licensed provider supervision assumed throughout.
- Compounded Protocol (standard)
- 1.5 mg subcutaneous 3 times per week; AM or PM empty stomach.
- Higher-Dose Specialist Protocols
- 3 to 8 mg for acute oncology, severe pancreatitis, or severe viral protocols; reserve for specialist coordination.
- Zadaxin Alternative (Approved Outside the US)
- 1.6 mg subcutaneous 2x per week; approximately equivalent weekly exposure.
- Onset and Assessment
- Mild flu-like sensation in first 24 to 48 hours; subjective and objective response builds over 2 to 6 weeks.
Vial reference
Units are for a U-100 insulin syringe (100 units = 1 mL), computed from the vial concentration.
| Vial | Dose range | Units per dose | Frequency | Notes |
|---|---|---|---|---|
| Thymosin Alpha-1 10 mg / 1 mL | 1.5 mg | 15 units | 3x per week | 0.1 mg per unit. AM or PM empty stomach. Zadaxin alternative 1.6 mg SC 2x per week. |
| TA-1 Complex 16.4 mg (TA-1 10 mg / Thymulin 6.4 mg) | 1.5 mg | about 9 units | 3x per week | 0.164 mg per unit. AM or PM empty stomach. Combined TA-1 plus Thymulin. |
Reference ranges as published in the source protocol document, not a prescription. To work out the draw for a specific vial and dose, use the Peptide Calculator.
Bottom line
Thymosin Alpha-1 has the strongest international clinical evidence base of any compounded immune peptide. It is approved (as Zadaxin) in 35+ countries outside the US and has been studied across over 11,000 human subjects. This is a peptide with real regulatory standing.
Two equivalent dosing patterns are in clinical use: compounded 1.5 mg SC 3x weekly or Zadaxin 1.6 mg SC 2x weekly. Higher doses (3 to 8 mg) exist in oncology and severe pancreatitis literature but should be reserved for specialist coordination.
Baseline labs matter: document CBC with differential and, where available, lymphocyte subsets. Counsel patients about the expected mild flu-like sensation in the first 24 to 48 hours of a new course.
TA-1 sequences well with Thymalin: complementary mechanisms make them often used together in extended immune-support protocols.
Chronic Viral Infections
Hepatitis B, hepatitis C, EBV, CMV reactivation indications
Critical Illness Immune Support
Severe acute pancreatitis CD4 percentage and infection rate improvement
Immunosenescence
Thymic involution counteraction in older adults; poor vaccine responder support
References
Citations sourced from PubMed and verified against the PubMed record.
- 1Simonova et al., 2025 Aging and Thymosin Alpha-1
- 2Tian et al., 2025 TA-1 in Severe Acute Pancreatitis
- 3Dinetz and Lee, 2024 Comprehensive Review of TA-1 Safety and Efficacy
- 4TA-1 in Chronic Hepatitis B Phase 3 TrialCitation under review
Regulatory status, cautions and contraindications
Active Solid Organ Transplant Immunosuppression
Coordinate with transplant team before initiating TA-1 therapy.
Known Hypersensitivity
Known hypersensitivity to TA-1 or excipients: contraindicated.
Pregnancy and Lactation
Insufficient data available; specialist coordination required before use.
Legal disclaimer
These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.
This peptide overview is for informational purposes only and does not constitute medical advice. The information provided here is not intended to diagnose, treat, cure, or prevent any disease. Peptide therapies should only be used under the guidance of a licensed healthcare provider, who can assess individual health needs and determine appropriate dosing and administration.
Always consult your healthcare provider before starting any new treatment, as misuse or improper dosing may lead to adverse effects. The efficacy and safety of peptide therapies have not been fully established in all cases, and ongoing medical supervision is essential.