Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-25. ← Back to Evidence Library
Thymalin: what the evidence says
At a glance
Thymalin is reported to be a registered medicine in Russia: UNVERIFIED, not checked against the Russian drug register. R1, R2
What it is: a mix of small peptides extracted from calf thymus (the immune gland in the chest), developed in the Soviet Union. R1
What the evidence says: a handful of Russian studies, mostly by the developer's own institute, report fewer infections and lower death rates in elderly people, and faster recovery markers in COVID-19. Study designs are poorly described and not independently repeated. R1, R2
Biggest risks: not well reported. It is an animal-tissue extract. Unknown
Rating
| Human Human evidence | Very limited: small Russian studies with unclear controls, all led by the developer group (Khavinson, St. Petersburg Institute of Bioregulation and Gerontology) R1, R2 |
| Animal Animal / lab evidence | Not rated here |
| Regulatory | Not FDA-approved (no Drugs@FDA record) · Russia: registered bovine thymus extract [UNVERIFIED: not confirmed directly on Russian GRLS primary registry] · WADA 2026: not named; S0 depends on Russian registration R4 |
| Established human dose | None recognized outside Russia. Study details lists what studies used where reported |
Evidence verdict: Human: Very limited Card verdict: Very limited (Russian clinical cohorts, developer-led)
This page reports what studies used. It is not dosing advice.
Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source
What is it?
Thymalin is a polypeptide extract from calf thymus, developed by V. G. Morozov and V. Kh. Khavinson. R1 Lab work suggests it contains short peptides such as KE and EW dipeptides. R3
Does it work?
- Human Elderly people (Russia/Ukraine): in 266 older people followed 6–8 years, the authors report that thymalin (alone or with the pineal extract epithalamin) was linked to 2.0–2.1 times lower death rates vs controls. How groups were assigned is not clear from the abstract, and the authors lead the developer's institute. R1
- Human COVID-19: adding thymalin to standard care was reported to speed the fall of inflammation markers (IL-6, CRP, D-dimer). Patient numbers are not given in the abstract. R2
- Unknown Independent trials outside Russia: none found.
Who ran the studies: every published human cohort we found was led by the developer group, V. Kh. Khavinson and colleagues at the St. Petersburg Institute of Bioregulation and Gerontology, which also developed and promotes thymalin. No independent group has repeated the results. R1, R2
Is it safe?
- Unknown Side effects are not described in the abstracts we read. R1, R2
- Unknown As an animal-gland extract, contamination and allergy are theoretical concerns.
Gray-market "research use only" Thymalin: extra risks
Unknown contents. Products sold online as "research use only" or "not for human use" are not made under drug-quality rules, so identity, strength and sterility are unknown. This is a general caution; we have not found testing data for this product specifically. Unknown
What we don't know
- Unknown Whether results hold up in independent randomized trials
- Unknown Side-effect rates
- Unknown What is in a gray-market vial labelled "thymalin" vs the Russian product
Is it legal?
Not FDA-approved in the US (no Drugs@FDA record, openFDA query Oct 24, 2026). Russia: reported as a registered medicine UNVERIFIED. EU, UK, Japan, China: UNVERIFIED not checked against EMA, MHRA, PMDA or NMPA. WADA: not named on the 2026 Prohibited List. S0 covers only substances with no current approval anywhere, so whether it applies depends on the Russian registration, which is UNVERIFIED R4.
Study details
These are doses researchers used, not recommendations.
R1 Human Human: Long-term follow-up in elderly people (Khavinson & Morozov 2003)
| Study | People / model | Route | Dose used | Follow-up | Reported | Side effects / dropouts | Citation |
|---|---|---|---|---|---|---|---|
| Khavinson 2003 | 266 elderly | Not in abstract | Not in abstract | 6–8 years (treatment first 2–3 years) | Mortality 2.0–2.1-fold lower with thymalin vs control | Not in abstract | PMID 14523363 |
R2 Human Human: COVID-19 add-on (Khavinson 2021)
Amounts and patient numbers not in abstract. PMID 33575961
R3 Animal Lab: peptide content (2023)
Full reference list (PubMed entries verified Oct 24, 2026)
- R1 Khavinson VKh, Morozov VG. Neuro Endocrinol Lett. 2003;24(3-4):233-40. PMID 14523363
- R2 Khavinson VK, et al. Stem Cell Rev Rep. 2021;17(1):285-90. PMID 33575961
- R3 The Influence of KE and EW Dipeptides in the Composition of the Thymalin Drug... Int J Mol Sci. 2023. PMID 37686182
- R4 WADA. World Anti-Doping Code International Standard: Prohibited List 2026 (in force Jan 1, 2026). https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf (text read Oct 24, 2026)
Disclaimer
This page summarizes published research for education and harm reduction; it is not medical advice or a recommendation to use Thymalin. Talk to a clinician you trust before using any drug, and report side effects to FDA MedWatch.
Approved for Adam Greene by Dr. Nova Reyes, 2026-10-25.