thymalin

a drug made from calf thymus glands, sold for immune support and to slow ageing. registered in the ussr in 1982 and never once entered into a trial registry. the largest human dataset belongs to the two men who made it.

tier D · healing · 0 registered trials · 44 yrs

verdict

a mixture of peptides extracted from calf thymus glands, registered as a medicine in the ussr in 1982 and sold for immune support and anti-ageing. it moves immune numbers: every group that has put it beside a control and counted t cells has watched them go up from baseline. the anti-ageing claim rests on one dataset of 266 older people, reported by the two men who developed the compound, published twice from that single cohort and unchecked by anyone else since. 44 years of published clinical reporting, and zero registered trials in any registry.

if you're asking whether thymalin and thymulin are the same thing: they are two different things, and the market sells them as one. thymalin is a mixture pulled out of calf thymus tissue, so it has no single sequence and no single mass. thymulin is one defined molecule, a nine amino acid peptide, Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, 858.9 g/mol. two vendor pages sold under the thymalin name publish thymulin's sequence, thymulin's mass and a formula of C33H54N12O15, then print a purity figure of 99 percent or better against it. one of those pages calls the material a natural extract containing multiple bioactive peptides in its own copy, then prints a single-molecule identity three paragraphs later. the literature does it too. a 2004 Kyiv paper carries thymalin in its title and thymulin in its English abstract.

if you're asking whether the mortality numbers are real: they are published, they are placebo-controlled, and they are much smaller than 266. the mortality comparison is 24 people on thymalin against 22 on placebo, and the paper describes stratification randomisation, a placebo arm and a double blind. six-year all-cause mortality reconstructs to 18 of 22 dead on placebo against 10 of 24 on thymalin. the 4.1-fold figure belongs to a separate 20-person group outside that randomisation. the paper's statistics stop at the p values on the mortality table. the second cohort in it, from the Kiev institute of gerontology, prints percentages that resolve to fractions of a person against its own denominators. the same dataset ran in Russian in 2002 and in English in 2003, so secondary sources count it twice. the developers reported both cohorts under their own names, and nobody outside those two institutes has tried to reproduce it in 23 years.

if you're asking what the best independently controlled human number is: it belongs to one piece of thymalin. Glu-Trp, a two amino acid fragment the developers isolated out of the extract, was licensed west, renamed IM862 and run in a 202-patient double-blind placebo-controlled phase 3 in AIDS-related Kaposi sarcoma. response 23 percent against 21 percent on placebo, p=0.46. median time to progression 16 weeks against 35 weeks on placebo, p=0.012, which the authors soften to may accelerate progression because the IM862 arm also had significantly less concurrent antiretroviral therapy at baseline, 88 against 96 percent, p=0.042. the same trial found a shorter time to response on drug, 8.5 weeks against 14, p=0.024. a 25-patient renal-cell phase 2 recorded zero objective responses. that programme stopped after 2007. IM862 is one dipeptide sprayed into the nose, and the extract is the mixture it came out of.

based on published evidence and the registry record. not medical advice.

why D-tier

d-tier, and the argument is about who checked. the efficacy answer splits in two. the immune-parameter effect is real and shows up against controls. the geroprotection number is enormous and has never been checked by anyone who does not stand to gain from it. the flagship 2003 paper does describe stratification randomisation, a placebo control and, verbatim, a double blind, and its mortality arms are 24 and 22 people, with 266 the total observed. its statistics stop at the p values on the mortality table, and the kiev cohort inside the same paper prints percentages that resolve to fractions of a person against its own denominators. count the rest of the human record: 293 pubmed entries, 13 trial-tagged, eight of those from before 1996, five with no stated sample size. the one modern prospective controlled study is 92 patients, single centre, open label, biomarker endpoints read as within-group fold change from baseline, zero deaths in either arm. a 2022 retrospective prints hospital mortality of 40.9, 28.4 and 20.6 percent with no denominators, which leaves those three figures uncomparable. every registry queried on 2026-07-25 returns zero. c is the band for a compound whose mechanism is plausible and whose data is thin, the shape of something preclinical still waiting its turn in humans. thymalin has had 44 years in humans, and what came back is a real placebo-controlled result that a single research lineage owns end to end, plus one outside double-blind placebo comparison, on its own glu-trp fraction, that failed on response. on top of that sits an identity problem the other d-tier entries do not have, with the marketed product carrying a different compound's sequence, mass and purity claim. f requires fake, a scam, or harm beyond reasonable doubt, and this is a nationally registered preparation with a granted composition patent by its developers and measurable nonspecific immune activity reported by groups in rostov, vladivostok, kharkiv and chieti that the developers do not run. d is where those two facts meet. the condition for moving is one registered, controlled, independently run trial of the extract itself.

the core tension

forty four years of published clinical history, and the smallest circle of people willing to vouch for any of it. on one side: a national registration certificate, a granted patent held by its developers, and a placebo-controlled double-blind cohort whose mortality arms are 24 and 22 people and whose numbers are large enough to sell a product on. on the other: statistics that stop at the p values on the mortality table, one dataset appearing twice in the literature, a second cohort inside it printing percentages that resolve to fractions of a person, every registry queried returning zero, no pharmacokinetics in any species, and no published assay of what is actually in the marketed material. the one time a piece of thymalin went in front of a placebo run by outsiders, it lost.

what it is

A drug made out of calf thymus glands, developed in Leningrad by Vladimir Khavinson and Vyacheslav Morozov and registered by the USSR Ministry of Health in 1982 under certificate 82/1108/8. It is a mixture of many peptides, and it has never been one defined molecule. The developers' own granted US patent specifies a weight distribution: polypeptides in a 600 to 6,000 Da band, 80 to 90 percent by weight at isoelectric point 3.5 to 6.7 and the remainder at pI 7 to 9. The 2021 clinical paper describes the same material as a complex of thymus peptides with molecular weight up to 10 kDa. Three named fractions appear across the literature: the dipeptides Lys-Glu and Glu-Trp and the tripeptide Glu-Asp-Pro. AMASS DrugCore, queried on 2026-07-25, holds no record for thymalin under any spelling. A tissue extract with many components has no single structure to register, so there is no SMILES, no InChIKey and no ChEMBL identifier.

what it does

It damps down inflammatory signals and shifts the markers on immune cells. Almost all of that has been measured in cells and in rodents. In LPS-stimulated human peripheral blood mononuclear cells from four donors, thymalin and its two named dipeptides lowered IL-1 beta, IL-6 and TNF-alpha by 1.4 to 6.0 fold. In cultured human haematopoietic stem cells, CD44 and CD117 expression fell 2 to 3 fold and CD28 rose 6.8 fold. The most informative cell work runs against the extract. An Italian group at Chieti-Pescara and Ancona ran thymalin at 100 ng/mL in THP-1 monocytes alongside four defined Khavinson peptides across three independent experiments. Every defined peptide reduced monocyte adhesion to endothelium. Thymalin increased it. Thymalin was also the reproducible exception to JNK downregulation, and drove the largest release of extracellular vesicles. Khavinson is a co-author on that paper. In rodents the reported effects are broad: tumour growth arrest in rats carrying transplanted sarcoma 45, accelerated reparative osteogenesis in a 48-rat mandibular defect model, raised cytokine output in mice used as an active comparator arm.

origin

One lineage, Leningrad then St Petersburg. Morozov and Khavinson filed the extract patent in 1985, registered the preparation in 1982, and remain authors on the largest human dataset published on it. The manufacturer named in the 2021 clinical paper is Samson-Med LLC. The developers state the order of invention themselves. In their 2013 review they write that the method of building short peptide bioregulators from the amino acid composition of tissue extracts was proposed in 1999, seventeen years after the extract was registered. Thymalin came first. Vilon, Thymogen and the Glu-Asp-Pro tripeptide were carved out of it afterwards, and every one of those fraction patents was filed after 1982. The founding 1982 publication in Voenno-Meditsinskii Zhurnal carries no abstract in PubMed at all.

why researchers are interested

Four decades of published clinical reporting is unusual in this market, and the numbers inside the developers' cohort are large. Mortality reported down 2.0 to 2.1 fold. Acute respiratory disease down 2.0 to 2.4 fold. Few compounds sold alongside it carry a national registration certificate and a pharmacopoeial history. There is also real independent work. Groups the developers do not run, in Rostov, Vladivostok, Kharkiv and Chieti, have measured effects in rats and in cultured human cells.

does it work

It moves immune numbers. The lifespan claim is the one nobody outside the developers' two institutes has ever checked. On immune parameters, every time a group has put thymalin beside a control and measured T cells, the numbers move. In the 2021 randomised COVID-19 study, 42 against 50, T lymphocytes rose 63.8 percent and CD4 rose 88.9 percent from baseline on thymalin while the control arm's T cell parameters, in the authors' own words, did not improve. Those are within-group changes and the paper prints between-group significance only for CRP, D-dimer, ferritin and ESR. One counter-example belongs here too: an Italian group found thymalin was the single agent that increased monocyte adhesion to activated endothelium while all four purified peptides decreased it. On geroprotection, one group measured it, got an enormous number, and nobody else has checked in 23 years. The 2003 paper does describe stratification randomisation, a placebo control and, verbatim, a double blind. Its mortality arms are 24 and 22 people, and the printed percentages reconstruct to whole people: 18 of 22 dead on placebo against 10 of 24 on thymalin over six years. Its statistics stop at the p values on the mortality table, and the Kiev half of the same paper prints percentages that resolve to fractions of a person against their own denominators. The registry answer is unchanged. AMASS TrialCore and a direct ClinicalTrials.gov query both return zero. Five basics are missing at once: a pharmacokinetic study, a half-life in any species, dose-ranging work, a systematic review, and a published composition assay of the marketed material. The only double-blind placebo-controlled result produced outside the developers' institutes landed on thymalin's Glu-Trp fraction, and it was negative: a 202-patient phase 3 with response 23 percent against 21 percent.

key facts

• molecular formula: none. a tissue extract with many components has no single molecular formula. vendor pages print C33H54N12O15, which is thymulin's formula
• molecular weight: 600 to 6,000 Da band per the developers' patent US-5070076-A; described as up to 10 kDa in the 2021 clinical paper. vendor pages print 858.9 g/mol, which is thymulin's mass
• amino acids: not a defined sequence. the fractions named in the literature are the dipeptides Lys-Glu and Glu-Trp and the tripeptide Glu-Asp-Pro
• half-life: not characterised in any species. no pharmacokinetic study appears in the 293 PubMed records
• type: calf thymus peptide extract, cytomedin class. a mixture of many peptides
• CAS: none assigned to the extract. vendor pages print 63340-72-7 alongside thymulin's sequence; thymulin's usual CAS is 63958-90-7
• 0 registered trials, any registry
• 293 pubmed records, 13 of them trial-tagged
• 266 largest human dataset, reported by its developers
• 1982 year of registration, ussr

frequently asked questions

What is Thymalin?

Thymalin is a drug made from the thymus glands of calves, sold for immune support and to slow ageing. The glands are minced and soaked in acid, and the peptides that come out of the tissue are the product. It is sold under the name Thymalin, also spelled Timalin, and the manufacturer named in the 2021 clinical study is Samson-Med LLC. Several western vendor pages sell it under thymulin's name and print thymulin's sequence and mass, and thymulin is a different compound. Thymalin was developed in Leningrad by Vladimir Khavinson and Vyacheslav Morozov and registered by the USSR Ministry of Health in 1982. It is a mixture of many peptides: the developers' granted US patent specifies it as a weight distribution of polypeptides across a 600 to 6,000 Da band, and the 2021 clinical paper describes a complex with molecular weight up to 10 kDa. It has no FDA or EMA record.

What does Thymalin do?

Two things are claimed for it, propping up the immune system and slowing ageing. The immune half is measurable. In the one modern controlled study, 92 patients with COVID-19 in St Petersburg, the thymalin arm's T lymphocytes rose 63.8 percent and CD4 rose 88.9 percent from baseline while the control arm's T cell parameters, in the authors' own words, did not improve. Each arm there is measured against its own starting point, and the paper prints no direct test between the two. The ageing half rests on its developers reporting mortality 2.0 to 2.1 fold lower on thymalin in a 266-person dataset of older people observed for 6 to 8 years. The mortality comparison itself is 24 people on thymalin against 22 on placebo, with 266 the total observed, and nobody outside their two institutes has checked the result in 23 years. In cells it lowers inflammatory cytokines. In LPS-stimulated human mononuclear cells from four donors, thymalin and its two named dipeptides reduced IL-1 beta, IL-6 and TNF-alpha by 1.4 to 6.0 fold. In cultured human haematopoietic stem cells, CD44 and CD117 fell 2 to 3 fold while CD28 rose 6.8 fold. In one 92-patient open-label COVID-19 study the thymalin arm showed larger within-group falls in IL-6, CRP and D-dimer than the control arm. What it does in humans over any longer horizon is not established: the record holds no pharmacokinetic study, no dose-ranging work and no registered trial.

How is Thymalin studied and administered in the literature?

The only modern human regimen documented in a controlled study is 10 mg intramuscular once daily for five days, used in a 92-patient open-label COVID-19 study in St Petersburg. Older Russian-language reports describe course-based intramuscular administration and, in one 1994 paediatric peritonitis report, local wound infiltration at 0.01 percent. There is no FDA-approved dosing protocol because there is no FDA record of the compound.

What are the side effects of Thymalin?

The published record contains no human pharmacovigilance dataset and no adverse-event table, so this cannot be answered from evidence. The closest finding in the literature is an animal one: a 1993 guinea pig study reported that thymalin stimulated allergization to a microbial antigen and established the possibility of allergic reactions to thymalin itself, with repeated injections producing a stronger sensitising effect than a single one. That is an immunogenicity finding in a heterologous animal-protein extract, and it is not a human result. Product identity is a separate and live problem: two vendor pages publish a different compound's sequence and mass under the thymalin name.

Is Thymalin FDA approved?

No. AMASS RegulatoryCore, which indexes FDA NDA and BLA records and EMA centralised marketing authorisations, returns no thymalin record, and AMASS DrugCore holds no drug record for it under any spelling. There is no US label, no orphan designation and nothing to read a section out of. The Russian registration from 1982 sits outside both Western registers, and its absence there is not evidence about it either way. The wider thymic-peptide family is also absent from FDA and EMA: thymalfasin and thymopentin both reach approval stage elsewhere with no FDA or EMA authorisation. What separates them from thymalin is the registered trial base, 41 and 9 against zero.

Is Thymalin the same as thymulin?

No. Thymulin is a defined zinc-dependent nonapeptide, Pyr-Ala-Lys-Ser-Gln-Gly-Gly-Ser-Asn, with a molecular weight of 858.9 g/mol and its own drug record. Thymalin is a heterogeneous extract with no sequence and no single mass. The two are routinely sold as one product: two vendor pages publish thymulin's sequence, mass and formula under the thymalin name and print a purity figure of 99 percent or better against it, and one of those pages describes the material in its own copy as a natural extract containing multiple bioactive peptides. Thymalfasin, thymostimulin and the rival Soviet extract Taktivin sit in the same cluster of names.

related peptides

• thymosin α-1: the defined thymic peptide with an actual registered trial base
• epithalon: same lab, same playbook, the pineal side of it
• pinealon: another khavinson short peptide graded on a similarly thin base

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.