Thymalin
Polypeptide fraction extracted from calf thymus. The Khavinson school in its original Soviet form: registered in Russia, given to soldiers, and now at the centre of a real supply crisis after Samson-Med stopped manufacturing it in October 2025.
1 · Identity
- Identity
- sequence-only / literature
- Aliases
- Thymalinum (EN); Timolin (EN); Тимолин (RU_LATIN)
2 · Mechanism — what the primary literature actually shows
A calf-thymus polypeptide fraction (Morozov extraction protocol: acetone dehydration → acetic acid + ZnCl₂ pH 3.4-4.0 → ultrafiltration Amicon PM-10 → lyophilization). The active principle is not a single sequence but a complex of low-molecular-weight peptides (Khavinson 2020 meta-analysis explicitly attributes the effect to "ultrashort peptides" within the fraction). At the cellular level, thymalin restores T-lymphocyte count and the ratio of T/B-subpopulations, normalises cellular immunity, phagocytosis and haematopoiesis. At the systems level, the most striking finding is its effect on CNS-immune axis: Korolev 2018 showed that thymus peptides correct behavioural and learning deficits in an MPTP Parkinson-like model in rats — a finding that connects thymic output to central nervous system function. Shcherbak 2005 (n=34 children) suggests thymalin reduces lipid peroxidation (POL) intermediates that remain elevated after conventional therapy alone.
How it works
calf thymus → polypeptide fraction (Morozov protocol) → T/B-cell regulation · phagocytosis → T-lymphocyte maturation + haematopoiesis → immune restoration · CNS-immune axis (Korolev 2018)
Key findings (5)
- Wistar rats 300-350g, MPTP Parkinson-like model: thymalin accelerates conditioned active avoidance reflex acquisition, corrects neurotoxin-induced behavioural deficits (Korolev 2018, n=80 rats)
- Piglets, 5 mg i.m.: increased lymphocyte fraction, decreased segmented neutrophils, increased phagocytosis, complement activation (Saliga 2010)
- Children 10-16y with chronic gastroduodenitis (n=34), thymalin 5 mg i.m. ×10d: pain syndrome reduced by 4.7 days vs conventional therapy alone; primary/secondary/intermediate POL products (which were 19.3%/32%/56% above control at baseline) normalised with thymalin but stayed high with conventional therapy (Shcherbak 2005)
- Ewes with postpartum endometritis: combined with endometrial polypeptides reduces mortality, shortens treatment time (Anokhova 2011)
- Radiation-exposed animals: thymus preparations restore immune function post-irradiation (Topuria 2004 — adjacent)
Evidence quality
Strong on cellular immunity mechanism — multiple direct studies with consistent findings. The Korolev 2018 CNS-immune axis is single-paper but well-controlled (MPTP model, n=80). Clinical translation data are Russian-only and small (Shcherbak n=34). Khavinson 2020 meta-analysis aggregates Russian clinical literature of variable statistical quality (Grigoriev 2019 statistical review notes this explicitly for the parallel pineal drug epithalamin).
Open questions (5)
- No ICH-GCP-compliant registration trials in NMPA / PMDA / DCGI / ANMAT / ANVISA jurisdictions. Russian Federation + CIS clinical literature only. Active principle uncharacterised: which ultrashort peptides within the fraction carry the effect?
- Active principle uncharacterised: which ultrashort peptides within the fraction carry the effect?
- CNS mechanism: how does a peripherally-administered thymus fraction modulate MPTP recovery?
- Samson-Med ceased thymalin manufacture October 2025 — supply-chain collapse means further clinical trials unlikely
- Lipid peroxidation reduction: anti-oxidant mechanism or reduced neutrophil-driven ROS production?
3 · Summary
Design distribution
| Design | Count | Distribution |
|---|---|---|
| CONTROLLED | 51 | ███████████████████████████████████████████████████ |
| CLINICAL_UNCONTROLLED | 49 | █████████████████████████████████████████████████ |
| ANIMAL | 42 | ██████████████████████████████████████████ |
| IN_VITRO | 16 | ████████████████ |
| REVIEW | 4 | ████ |
| CLINICAL_CASE | 1 | █ |
| UNGRADED | 41 | █████████████████████████████████████████ |
4 · Possible mechanisms — candidate list
5 · Pathways — questions the corpus does not yet answer
- Pathway
- Falsification experiment for open question 1. No ICH-GCP-compliant registration trials in NMPA / PMDA / DCGI / ANMAT / ANVISA jurisdictions. Russian Federation + CIS clinical literature only. Active principle uncharacterised: which ultrashort peptides within the fraction carry the effect?
- Blocked by
- See synthesis evidence quality section for barriers.
- Pathway
- Falsification experiment for open question 2. Active principle uncharacterised: which ultrashort peptides within the fraction carry the effect?
- Blocked by
- See synthesis evidence quality section for barriers.
- Pathway
- Falsification experiment for open question 3. CNS mechanism: how does a peripherally-administered thymus fraction modulate MPTP recovery?
- Blocked by
- See synthesis evidence quality section for barriers.
- Pathway
- Falsification experiment for open question 4. Samson-Med ceased thymalin manufacture October 2025 — supply-chain collapse means further clinical trials unlikely
- Blocked by
- See synthesis evidence quality section for barriers.
- Pathway
- Falsification experiment for open question 5. Lipid peroxidation reduction: anti-oxidant mechanism or reduced neutrophil-driven ROS production?
- Blocked by
- See synthesis evidence quality section for barriers.
6 · Bibliography — Russian primary sources
- primenenie-immunomodulyatora-timusnogo-proishozhdeniya-dlya-korrektsii-immuniteta-u-zhivotnyh
- vozmozhnost-korrektsii-peptidami-timusa-narusheniy-obucheniya-na-modeli-parkinsonopodobnogo-sindroma
- sravnitelnoe-vliyanie-polipeptidov-endometriya-i-timalina-na-nekotorye-pokazateli-immuniteta-i-gemostaza-v-opytah-in-vitro-i-in-vivo
- meta-analiz-immunomoduliruyuschey-aktivnosti-lekarstvennogo-peptidnogo-preparata-timalina
- vliyanie-timalina-na-klinicheskoe-techenie-i-pokazateli-perekisnogo-okisleniya-lipidov-u-detey-s-hronicheskim-gastroduodenitom
- effektivnost-preparatov-timusa-pri-luchevoy-patologii-zhivotnyh
- peptidnaya-bioregulyatsiya-rezistentnosti-k-ekstremalnym-vozdeystviyam
- sravnitelnoe-deystvie-timalina-timogena-i-ronkoleykina-na-sostoyanie-immuniteta-i-gemostaza-pri-razvitii-endometrita-posle-kesareva
- vliyanie-kompleksa-immunoaktivnyh-peptidov-tinrostima-na-aktivnost-proteoliticheskih-fermentov
- profilaktika-orvi-u-detey-v-ambulatorno-poliklinicheskih-usloviyah
- sochetannoe-vliyanie-polipeptidnyh-kompleksov-na-razvitie-organotipicheskoy-kultury-tkaney-krys
- lekarstvennye-peptidnye-preparaty-proshloe-nastoyaschee-buduschee
- vliyanie-timalina-na-adaptivnyy-immunitet-pri-provedenii-kompleksnoy-terapii-patsientov-s-covid-19
- identifikatsiya-korotkih-peptidov-optimizatsiya-targetnyh-terapevticheskih-svoystv-lekarstvennogo-preparata-timusa
- sravnitelnoe-deystvie-timalina-epitalamina-i-vilona-na-sostoyanie-immuniteta-u-bolnyh-s-oslozhnennym-techeniem-ostrogo-appenditsita
- sravnitelnoe-issledovanie-immunomoduliruyuschey-aktivnosti-peptidov-tinrostima-i-timalina
- vliyanie-timalina-na-obmen-gamk-v-tkani-golovnogo-mozga-10-dnevnyh-krys-pri-tsiklofosfamidnoy-immunosupressii
- vliyanie-timalina-na-trombotsitarnuyu-adgeziyu-u-detey-stradayuschih-infektsionnym-endokarditom
- eozinofily-kak-prediktory-sklonnosti-k-trombozam-i-tyazhesti-zabolevaniya-covid-19-pri-razlichnyh-vidah-terapii
- vozdeystvie-polipeptidov-timusa-na-rabotu-stress-sistemy
Inventor (detail): **Joint** — V.G. Morozov (biochemist, Kirov Academy) and V.Kh. Khavinson (gerontologist). Both names appear on every foundational paper. US Patent 5,070,076 (1991) lists both as co-inventors. **Khavinson was the younger partner** — the chemistry comes from Morozov.
First publication: Morozov V.G., Khavinson V.Kh. *Isolation, purification, and identification of an immunomodulatory polypeptide found in the thymus of calves and humans.* **Biokhimiya, 1981, 46:1652–1659** (PMID 7295826). Earlier isolation work: Morozov V.G., Khavinson V.Kh., Pisarev O.A. *Dokl. Akad. Nauk SSSR*, 1977, 233:491–494. Mechanism: Morozov & Khavinson, *Dokl. Akad. Nauk SSSR*, 1978, 240:1004–1007.
Peptide kind: **Polypeptide fraction** from calf (veal) thymus; molecular mass 1–10 kDa; ultrafiltered to remove >10 kDa. The active core was later (Morozov et al., 2000; Zhurkovich et al., 2020) deconvoluted by RP-HPLC into three synthetic short peptides: **EW (Thymogen), KE (Vilon), EDP (Crystagen)**.
Below: substantive excerpts from 6 Russian primary papers. Click each title to expand the Russian/English abstract.
6/6 papers with substantive abstracts · 6,780 characters of Russian/English pharmacological text extracted · 6 Russian abstracts · 6 English abstracts · 5/6 relevance-classified.
Extracted findings (4 models · 5 mechanism terms · direction: ↑3 ↓2 ↺3 across 6 papers)
- Model organisms
- in vitro, овцематок, поросят
- Doses / concentrations
- 5 мг
- Mechanism terms
- иммунной системы, иммунную систему, регенерации, тимуса, тимусного
- Effect direction
- 3× increase · 2× decrease · 3× restoration/normalisation
[2010] Применение иммуномодулятора тимусного происхождения для коррекции иммунитета у животных
[2018] Возможность коррекции пептидами тимуса нарушений обучения на модели паркинсоноподобного синдрома
[2011] Сравнительное влияние полипептидов эндометрия и тималина на некоторые показатели иммунитета и гемостаза в опытах in vitr
[2020] МЕТА-АНАЛИЗ ИММУНОМОДУЛИРУЮЩЕЙ АКТИВНОСТИ ЛЕКАРСТВЕННОГО ПЕПТИДНОГО ПРЕПАРАТА ТИМАЛИНА
[2005] Влияние тималина на клиническое течение и показатели перекисного окисления липидов у детей с хроническим гастродуоденито
[2004] Эффективность препаратов тимуса при лучевой патологии животных
7 · Bibliography — PubMed corpus
8 · Corroboration
- Corpus source
- PubMed (eutils) and OpenAlex, swept against this compound by PMID. Last verified 26.08.2026.
- Identity source
- PubChem CID — verified live. InChIKey —. Live fetch on 26.08.2026.
- Provenance
- St. Petersburg Institute of Bioregulation and Gerontology (1990) Morozov VG — Thymic peptide complex; immunomodulation
9 · Open questions
- 4 B-grade paper(s) — verify COI flag and replicate independently before treating as decision-grade.
- Most of the published evidence for this compound is from the group that developed it. Where independent replication exists, we flag it in the mechanism block above; where it doesn't, treat mechanism claims as developer-side.