Thymosin Alpha-1

What people use it for

• Chronic hepatitis B and C (approved in some countries)
• Immune support (popular use)

What Thymosin Alpha-1 does in the body

A natural peptide produced by the thymus. It enhances T-cell maturation and function and modulates immune signalling (including toll-like receptors), helping the immune system respond to infections.

Strength of evidence

Moderate: clinical trials for hepatitis and as a vaccine adjunct; mixed results in other conditions.

Look up the evidence

• Reviews on PubMed: Summaries of the published research
• Clinical trials on PubMed: Published studies in people
• ClinicalTrials.gov: Registered trials, past and ongoing
• Prescribing information (DailyMed, US): Official US label
• Patient leaflets (emc, UK): Official UK product information

Live searches of official databases. New to the terms? See the glossary.

Reported side effects & risks

• Injection-site discomfort
• Generally well tolerated in trials

Who should avoid it or take extra care

• Organ transplant recipients on anti-rejection medicines
• Pregnant or breastfeeding
• Autoimmune disease (talk to your doctor first)

Not a complete list. Check with a doctor or pharmacist about your own health and medicines.

Regulatory status

Approved as Zadaxin in a number of countries outside the US. Not FDA-approved.

How it's taken

Route: Injection under the skin, usually twice a week

How long it lasts (half-life): About 2 hours

Storage

Unreconstituted (powder) vials are usually kept refrigerated or frozen and away from light. Once mixed with bacteriostatic water, keep refrigerated and do not freeze; follow the supplier's stated beyond-use date.

Mixing guides

How much water to add and what each syringe mark holds, worked out for your own dose:

• 5 mg vial
• 10 mg vial