Thymalin vs thymosin alpha-1 at a glance
| Compared | Thymalin | Thymosin alpha-1 |
|---|---|---|
| What it is | Peptide mixture extracted from calf thymus | One purified 28-amino-acid thymus peptide |
| Main use | Immune support (Russia) | Chronic hepatitis B, immune support |
| Evidence | Small Russian studies | Dozens of trials, thousands of patients |
| Approval | Used as a medicine in Russia | Approved as Zadaxin in over 30 countries; not FDA |
How are thymalin and thymosin alpha-1 different?
Thymalin is a natural mixture of many peptides taken from calf thymus glands, while thymosin alpha-1 is a single, precisely defined peptide made in a lab. A defined single molecule is easier to dose, test and compare across studies.
Both aim to support the immune system, which matures T cells in the thymus.
What does the research show for each?
Thymosin alpha-1 has been tested in many trials, mostly in hepatitis B and C, cancer and severe infections, with mixed but substantial results. Thymalin’s evidence comes mainly from Russian studies in elderly people that reported better immune markers and survival, but they were small and haven’t been repeated elsewhere.
How do the risks compare?
Both are generally reported as well tolerated, mostly with injection-site reactions. Thymalin comes from animal tissue, so purity and sourcing matter more.
Which is legal?
Neither is FDA-approved. Thymosin alpha-1 is approved in over 30 countries as Zadaxin, and its page lists that label dose with its source; thymalin is used in Russia.