Thymalin: The Russian Thymus Peptide Extract
Thymalin explained: a thymus-derived peptide complex registered in Russia, how it differs from thymulin and thymosin alpha-1, the evidence and the risks. Not medical advice.
Anonymous user report. Not medical advice. Peptides discussed are not FDA-approved for the uses described. Editorial process →
Short answer
Thymalin is a mixture of peptides extracted from calf thymus, developed in the Soviet Union in the 1970s and registered in Russia as an immune modulator. It is promoted online for immunity and longevity. It is not approved in the US, Canada or the EU, and most evidence comes from Russian studies that have not been independently replicated. Peptide Confessions does not publish dosing, timing, injection or sourcing guidance.
Thymus peptides compared
Last reviewed October 15, 2026.
| Name | What it is | Status |
|---|---|---|
| Thymalin | Animal-derived peptide mixture | Registered in Russia; not approved in US/Canada |
| Thymulin | Single zinc-dependent nonapeptide hormone | Research only |
| Thymosin alpha-1 | 28-amino-acid peptide | Approved in some countries (Zadaxin) for hepatitis B; not US/Canada |
| Thymogen | Synthetic dipeptide (Glu-Trp) | Registered in Russia |
Evidence and risks
Russian studies, many from the same research group, report effects on immune markers and, in older adults, on mortality; these were small and not to modern standards. Because it is extracted from animal tissue, batch quality matters, and products sold online outside Russia's regulated supply are unverified. People with autoimmune disease, cancer or transplants should be especially cautious. Related: thymosin peptides.
related peptides:
More confessions from the archive
Community Q&A
- What is thymalin?
- A calf-thymus peptide extract registered in Russia as an immune modulator.
- Is thymalin the same as thymulin?
- No. Thymulin is a single defined peptide hormone; thymalin is an extract mixture.
- Is thymalin approved?
- Not in the US, Canada or the EU.
- Does this page give dosing advice?
- Peptide Confessions does not publish dosing, timing, injection or sourcing guidance.
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