Peptide dossier, updated Nov 2, 2026
Thymalin
Thymalin, a polypeptide extract of calf thymus. Not a single defined peptide, though sellers and papers sometimes treat its KE and EW dipeptides as the active parts. A Russian immunomodulator made from thymus tissue. It is registered as a drug in Russia, and nearly all published research on it comes from Russian and Ukrainian groups. It has no FDA approval. It is often grouped with the short “bioregulator” peptides, but its registration describes an extract. This page lays out what each source actually says.
See all 7 verified records for Thymalin on the Records page
In plain terms
Approved for: In Russia, per the state drug register entry we read, a freeze-dried thymus extract for intramuscular injection (Timalin, registration LS-000267). Nothing from FDA that we found. We did not read the Russian label’s indications.
What it is: An extract from the thymus gland of calves, containing a mix of small proteins and peptides. It is not one lab-made peptide.
What it is said to do, and by whom:
- Researchers, 2002, from a St. Petersburg gerontology institute: in 266 elderly people followed for 6 to 8 years, thymalin and a pineal extract, taken for the first 2 to 3 years, were linked to fewer respiratory illnesses fewer heart-disease and other conditions, and lower mortality than a control group.
- Researchers, 2022: in a hospital study of severe COVID-19 patients, mortality was 40.9% with standard care, 28.4% with tocilizumab and 20.6% with thymalin.
- We did not collect sellers’ claims for this compound.
How strong the evidence is: Weak by Western standards. The human studies we found are small or observational, from a closely linked set of Russian groups, and we found no placebo-controlled trial registered outside Russia.
Regulatory status
What we looked for, and what we found.
What we found
- Russia. The RLS drug encyclopedia entry for Timalin shows registration LS-000267 of Feb 26, 2010 to Samson-Med, with a validity date of Dec 18, 2027, and a history that includes reissue under Eurasian Economic Union rules. The page lists the active ingredient as “thymus extract” and has no indications section. RLS entry (in Russian)
- WADA, 2026. No entry for thymalin in the text we searched.
What we did not find
- We did not read the Russian prescribing information, so we cannot say what uses it is registered for.
- We found no FDA document about thymalin. We did not check EU or other regulators.
- We did not confirm the manufacturer’s current status, or whether other registrations exist in other countries.
Published research
PubMed returns 293 results for thymalin as of Nov 2, 2026, many in Russian-language journals. We read the abstracts of the papers below.
What the papers show
- Elderly cohort, 2002. Authors from the St. Petersburg Institute of Bioregulation and Gerontology and a Kiev gerontology institute followed 266 elderly and older people for 6 to 8 years; thymalin and epithalamin were given in the first 2 to 3 years. They report 2.0 to 2.4 times fewer acute respiratory illnesses, fewer cases of ischemic heart disease, hypertension and other conditions, and 2.0 to 2.1 times lower mortality with thymalin, all compared with a control group. The abstract does not say how people were assigned to groups or whether anyone was blinded. Adv Gerontol PubMed
- Severe COVID-19, 2022. Three groups of middle-aged and elderly patients: basic therapy, plus tocilizumab, or plus thymalin. Hospital mortality was 40.9%, 28.4% and 20.6%. The abstract does not say how patients were assigned. Adv Gerontol PubMed
- Cells, 2020. In human stem cells, thymalin raised a marker of mature T cells 6.8-fold. This is a laboratory study. Bull Exp Biol Med PubMed
- Mechanism, 2023. A computer-modeling and gene-expression paper on the KE and EW dipeptides described as active parts of thymalin. It describes thymalin as a polypeptide extract of thymus. Int J Mol Sci PubMed
Read with care
- The key human papers share authors and institutes linked to the same research program. We found no independent replication.
- The COVID-19 abstract does not describe randomization or blinding, so the mortality figures should not be read as a trial result.
- We read abstracts, not full text, funding or disclosures.
Timeline
Newest first. Every entry links to the document it comes from.
- Government or registry record
- Journal
- Oct 30, 2026RegulatoryHHS publishes draft policy pausing enforcement on six peptides; Thymalin is not one of them
The draft policy’s appendix names six peptides: BPC-157, epitalon, KPV, MOTS-c, Semax and TB-500. The policy is a draft and not FDA approval. We read the appendix through a text extraction.
- July 23–24, 2026RegulatoryFDA advisory committee meets on seven peptides; Thymalin is not among them
The committee recommended six of the seven, all nonbinding. FDA’s notice of the meeting does not list Thymalin.
- Feb 26, 2010RegistrationTimalin registered in Russia (LS-000267)
Registration date per the RLS drug encyclopedia entry. Holder: Samson-Med.
- 2002LiteratureElderly cohort study reports fewer respiratory illnesses
266 people followed 6 to 8 years. Published in Adv Gerontol.
Still not covered
Left off rather than guessed:
- HHS policy: we read the draft policy appendix through a text extraction, not as the original PDF layout. It names six covered peptides and not thymalin.
- FDA review: we found no FDA briefing document or advisory committee evaluation for thymalin. FDA’s notice for the July meeting does not name it.
- Russian label: not read. The uses it is registered for are not stated on this page.
- Composition: the register says thymus extract. We did not verify what peptides it contains or in what amounts.
- Independent trials: we found none. We did not search Russian or Ukrainian trial registries.
- Manufacturer and other registrations: not researched.
- Patents and SEC filings: not researched for this dossier.
- Seller claims and independent lab reports: how gray-market product is marketed versus what testing finds. We have not collected testing data.
- Unread items: full text of most papers; EU and other non-US regulators and registries; WADA lists for years other than 2026; FDA warning letters beyond those listed, which rest on web searches.