Immune
Thymosin Alpha-1
Approved in some countries; not Canada or USApproved drugTA1ThymalfasinZadaxin
A 28-amino-acid peptide from the thymus that helps regulate the immune system. As thymalfasin (Zadaxin) it's approved in dozens of countries, mostly in Asia, as an add-on for hepatitis B and C and some immune problems. It's not approved in Canada or the US.
- Canada
- Not authorized; seized by Health Canada in 2025
- United States
- Not approved (orphan designations only)
Download profile Opens in Vialchemy on your iPhone, where it's added to your Library as your own.
Not medical advice — talk to your doctor before making medical decisions.
At a glance
- Class
- Immune modulator
- Mechanism
- Supports T-cell function
- Evidence
- Approved abroad; clinical trials for hepatitis and other uses
- Canada
- Not authorized
- Us
- Not approved
- Half Life
- About 2 hours
- Routes
- SubQ
- Common Side Effects
- Site discomfort; generally well tolerated in trials
- Key Cautions
- Immune effects with autoimmune disease or transplant meds
What the research says
Is there real human evidence?
More than most peptides here. It's approved as thymalfasin in many countries and studied in hepatitis, sepsis and as a vaccine add-on, with mixed results.
With autoimmune disease or immunosuppressants?
It's designed to change immune activity. Anyone with autoimmune disease or on transplant or immune-suppressing medicine should talk to their doctor first.
Get medical care if
- Redness, heat, swelling or pus at a site that spreads or comes with fever
- Hives, swelling of the face or throat, or trouble breathing (call 911)
Buying and quality
- Not authorized by Health Canada. Products sold online as "research use only" are illegal to sell for human use in Canada, and the label doesn't change that.
- Health Canada warns these products may contain too much, too little or none of the peptide, plus contaminants like endotoxins, solvents, heavy metals or bacteria.
- A certificate of analysis (COA) from the seller isn't independent proof. A 98% purity result still leaves 2% unidentified.
- If you use it anyway: one clean needle per injection, sterile technique, label and date every vial, and stop if a site gets hot, red and spreading.
Dose calculator
Doses are set with your prescriber. This converts a dose you already have into what to draw; it doesn't recommend one. Check every number against your syringe and your vial's label.
Doses left in the vial
A blend vial
Not medical advice — talk to your doctor before making medical decisions.
Sources
Researched 2026-10-27. Trial results and approval status change.
General education, not medical advice. Nothing here is a dose recommendation. Doses, schedules and changes are set with a prescriber.