Thymosin Alpha-1 Dosage Chart
The internationally-labeled 1.6 mg twice-weekly protocol and off-label immune support cycles.
Educational tool — not medical advice. This calculator provides estimates based on population averages and published trial data. Outputs are not clinical recommendations and do not replace evaluation by a qualified prescriber. Do not start, stop, or change a peptide therapy based on the result of this tool.
Thymosin Alpha-1 (Zadaxin) is approved in over 35 countries for chronic hepatitis B and C, immune restoration in cancer patients, and as a vaccine adjuvant. It is not FDA-approved in the United States but is widely used off-label through 503A/503B compounding pharmacies for general immune support. The labeled dose of 1.6 mg twice weekly is the most evidence-supported protocol.
Thymosin Alpha-1 at a Glance
| Labeled dose (Zadaxin) | 1.6 mg subQ, 2× per week |
|---|---|
| Off-label immune support | 1.6 mg subQ, 2× per week, 4–12 week cycles |
| Route | Subcutaneous injection |
| FDA status | Not FDA-approved (US). Approved in 35+ countries for hepatitis indications. |
| Source quality | Strong international clinical trial base for hepatitis indications. Off-label immune support is practitioner-derived. |
| Common vial size | 1.6 mg lyophilized powder |
Thymosin Alpha-1 Reconstitution Chart
How vial size, bacteriostatic water volume, and insulin-syringe units convert for Thymosin Alpha-1. Use this to translate a prescribed mcg or mg dose into a syringe measurement.
| Vial size | Bac water | Concentration | Dose → insulin-syringe units (U-100) |
|---|---|---|---|
| 1.6 mg | 1 mL | 1.6 mg/mL |
|
U-100 syringe reference: 100 units = 1.0 mL. So 10 units = 0.1 mL, 25 units = 0.25 mL, 50 units = 0.5 mL. Zadaxin is supplied as a single-dose vial — full reconstitution is one dose. Compounded preparations may differ.
Thymosin Alpha-1 Dosing by Use Case
Commonly cited protocols vary by what Thymosin Alpha-1 is being used for. The table below summarizes typical ranges reported in clinical practice and published literature.
| Use case | Typical dose | Frequency | Cycle length | Notes |
|---|---|---|---|---|
| Chronic hepatitis B/C (international label) | 1.6 mg | 2× per week | 6–12 months per international labeling | Labeled use in 35+ countries. |
| Immune support (off-label) | 1.6 mg | 2× per week | 4–12 weeks | Off-label compounded use; common in convalescent care and immunocompromised patients under clinician supervision. |
| Cancer adjuvant (off-label) | 1.6 mg | 2× per week | Coordinated with oncology team | Use only under direct oncologist supervision; not a substitute for cancer therapy. |
Thymosin Alpha-1 has the most robust international clinical safety data among the immune-modulating peptides on this site.
- •Common side effects: injection-site reactions, transient flu-like symptoms in the first few doses (usually self-resolving).
- •Generally well-tolerated in 30+ years of international clinical use.
- •Activates immune signaling — caution in autoimmune disease and patients on immunosuppressants.
- •Not FDA-approved in the US, but the international approval base is one of the strongest in this section.
- •Active autoimmune disease without specialist clearance
- •Organ transplant patients on immunosuppression (consult transplant team)
- •Pregnancy or breastfeeding (limited data)
Thymosin Alpha-1 Dosing FAQ
International labeled hepatitis protocols run 6–12 months. Off-label immune support cycles are typically 4–12 weeks. Most clinicians do not run continuous indefinite use.
Approval pathways and clinical-trial requirements differ by country. The molecule is the same; the FDA simply has not granted US approval. Compounded versions are widely used in the US through 503A/503B pharmacies under clinician prescription.
Thymosin Alpha-1 has been studied as a vaccine adjuvant and is not contraindicated with vaccination in published literature. Specific timing should be coordinated with your prescriber.
Sources
Related Dosage Charts
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See Thymosin Alpha-1 guideMedical Disclaimer: This content is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare provider before beginning any peptide therapy treatment.