In short
An immune-modulating peptide (thymalfasin) studied in infections, cancer and COVID-19. Meta-analyses disagree on COVID-19. Not found in Health Canada's Drug Product Database.
Also known asthymalfasin
CategoryImmune
Canada statusNot authorized in Canada (approved elsewhere)
Human evidence Moderate: some randomized human trials, specific uses (mixed, condition-specific)
Last reviewedNovember 10, 2026
How strong is the human evidence?
- Cell & animal
- Small human studies
- Some randomized trials
- Large randomized trials
What is Thymosin Alpha-1?
Thymosin alpha-1 is a peptide originally isolated from the thymus. As thymalfasin it has been studied in hepatitis, cancer, sepsis and COVID-19 (Dominari et al. 2020 review).
Is Thymosin Alpha-1 legal in Canada?
Not authorized: no thymalfasin product found in the Drug Product Database.
What the research shows
- A 2023 meta-analysis (Soeroto et al.) found lower COVID-19 mortality with Tα1, with high heterogeneity, and called for RCTs.
- Another 2023 meta-analysis (Shang et al.) found no significant effect on mortality and did not support its use in COVID-19.
What it doesn't show
- No good evidence for general "immune boosting" in healthy people.
Common questions
Is thymosin alpha-1 legal in Canada?
It is not authorized by Health Canada.
Thymosin alpha-1 vs thymosin beta-4?
Different peptides: alpha-1 is studied as an immune modulator; beta-4 is involved in tissue repair (TB-500 is based on part of it).
Sources
- Health Canada Drug Product Database (searched Nov 10, 2026)
- Dominari A et al. Thymosin alpha 1: a comprehensive review of the literature. World J Virol 2020
- Soeroto AY et al. Thymosin alpha-1 in COVID-19: SR, meta-analysis and meta-regression. Inflammopharmacology 2023
- Shang W et al. Thymosin alpha1 in adult COVID-19: SR and meta-analysis. Int Immunopharmacol 2023
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