LA LABResearch Reference Document
Compound Guide
Thymosin Alpha-1 (TA1) — Thymalfasin / Zadaxin
Quick Start
Approved in 35+ Countries — Not FDA Approved
Thymosin Alpha-1 (synthetic form: thymalfasin; brand name Zadaxin) is approved in more than 35 countries including China, Italy, and various Asia-Pacific nations for Hepatitis B and C treatment, and as an adjunct in cancer therapy and sepsis. It is NOT FDA-approved in the US. FDA placed it in Category 2 (September 2023), then removed it (September 2024), with PCAC review December 2024.
What It Is
Thymosin Alpha-1 is a 28-amino acid peptide naturally produced by the thymus gland. It is the first thymosin fraction described to have significant immunomodulatory activity. The synthetic form (thymalfasin) is identical to the naturally occurring peptide and is the active ingredient in Zadaxin. It acts as a biological response modifier — enhancing immune function rather than suppressing it.
Research Dosing
1.6 mg SubQ twice weekly (e.g. Monday and Thursday). The standard 6-month HBV protocol uses this dose continuously. For immune support research, some protocols use 1.6 mg 2–3× per week for 4–12 weeks. No ramp-up required.
Regulatory Status
Approved in 35+ countries for HBV, HCV, and cancer adjunct. NOT FDA-approved. FDA removed from Category 2 September 2024; PCAC reviewed December 2024. TESTS BMJ 2025 trial showed negative primary endpoint for sepsis. Not on WADA prohibited list. For research purposes only in the US and SA context.
Dosing Protocol
| Protocol | Dose | Frequency | Duration | Context |
|---|---|---|---|---|
| HBV Standard (Zadaxin) | 1.6 mg | Twice weekly (Mon + Thu) | 6 months | Approved clinical protocol for hepatitis B |
| Immune research | 1.6 mg | 2–3× weekly | 4–12 weeks | General immune-modulation research |
| Adjunctive | 1.6 mg | Twice weekly | With active protocol | Used alongside other treatments in international approved contexts |
Supplies & Reconstitution
Reconstitution Math — 5 mg Vial (3 mL BAC)
| Target Dose | Units (U-100) | Doses / Vial |
|---|---|---|
| 0.5 mg | 30.0 units | 10 |
| 1 mg | 60.0 units | 5 |
| 1.6 mg | 96.0 units | 3.1 |
Reconstitute the 5 mg vial with 3.0 mL bacteriostatic water → 1.67 mg/mL. U-100 syringe = 100 units per mL. Swirl gently — do not shake. Refrigerate 2–8°C.
Reconstitution Steps
01
Warm the vial
Remove from freezer 10–15 minutes before reconstitution. Allow to reach room temperature.
02
Swab both stoppers
Wipe the tops of both vials with fresh alcohol swabs. Air-dry.
03
Draw and inject BAC water
Draw BAC water and let it run slowly down the inside wall of the peptide vial. Do not jet onto the powder cake.
04
Swirl gently
Swirl until clear. Solution should be colourless to faint yellow. Do not shake.
05
Refrigerate
Store at 2–8°C for up to 30 days. Do not freeze after reconstitution. Protect from light.
Mechanism of Action
TLR Signalling
Activates Toll-like receptor 2 (TLR2) and TLR9 signalling on dendritic cells and plasmacytoid DCs. This triggers innate immune activation, type-I interferon production, and bridges innate to adaptive immunity.
T-Cell Activation (Th1 Shift)
Promotes differentiation and maturation of T-helper 1 (Th1) cells, and augments cytotoxic T-lymphocyte (CTL) activity. Key mechanism for its antiviral effects in HBV and HCV research. Shifts immune response toward cellular immunity.
Dendritic Cell Maturation
Promotes dendritic cell maturation and antigen-presenting function. Mature DCs are required for effective T-cell priming, relevant to both viral clearance and adjuvant cancer therapy research contexts.
No Immunosuppression
Unlike corticosteroids or calcineurin inhibitors, TA1 does not suppress immune function. It is a biological response modifier — it enhances responses that are deficient rather than globally suppressing inflammation.
Key Research
| Study / Trial | Design | Finding |
|---|---|---|
| Multiple RCTs (Zadaxin era) | HBV and HCV; 26–52 weeks | HBeAg seroconversion and HBV DNA suppression in multiple trials; approved basis in 35+ countries |
| Cancer adjunct studies | Lung, colon, breast cancer + chemo | Improved immune recovery post-chemotherapy in multiple open-label and controlled studies |
| TESTS trial (BMJ 2025) | RCT; n=1,100+; sepsis; 28-day mortality | Primary endpoint not met — no significant mortality difference vs placebo in sepsis |
| COVID-19 research | Observational; China 2020 | Suggested reduced mortality in severe COVID-19; not confirmed in RCTs |
Storage
| State | Temperature | Duration | Notes |
|---|---|---|---|
| Lyophilised (powder) | −20°C (freezer) | Up to 24 months | Protect from light and moisture |
| Reconstituted (liquid) | 2–8°C (refrigerator) | Up to 30 days | Do not freeze after reconstitution |
| Short-term (travel) | <25°C | Up to 72 hours | Avoid heat and direct sunlight |
Disclaimer
This document is an educational research reference only. Thymosin Alpha-1 is not FDA-approved in the United States. Approved uses in other jurisdictions (HBV, HCV, cancer adjunct) require supervision by a qualified medical professional. By purchasing from LA LAB you confirm you are 18+ and that products are for research purposes only.