Thymalin is a thymus-derived peptide bioregulator studied for immune modulation and aging research; this guide compiles reported examples for educational use only, not medical advice.
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Thymalin Guide: Available Now
Educational use only — not medical advice. This guide summarizes information reported in published research and community practice for educational purposes. It is not medical advice and not a recommendation to use any compound. Any doses, schedules, or combinations shown are examples of what has been reported, not instructions for you. Many peptides described here are research compounds that are not FDA-approved for the uses discussed and may be investigational or restricted. Effects, risks, and legal status vary; individual needs and results vary. Consult a qualified, licensed healthcare professional before making any decision. Do not use this content to diagnose, treat, or dose yourself.
Thymalin at a glance
What it is
A polypeptide complex (multiple low-molecular-weight peptides, <10 kDa) extracted from calf thymus tissue, developed as a peptide bioregulator by the Khavinson research group.
Researched for
Immune modulation, T-cell function, and geroprotective (anti-aging) effects in Russian clinical and community research.
Plasma half-life
No published pharmacokinetic study establishes one. A half-life describes a molecule, and this is a mixture rather than a single sequence, so the figures that circulate for it cannot be traced to a measurement.
Regulatory status
Registered as an immunomodulatory medicine in Russia; not FDA-approved and not EMA-approved; sold in the US and elsewhere as a research-use-only chemical.
Educational reference. This page does not publish dose ranges or reconstitution arithmetic.
What it is / mechanism
Thymalin is not a single molecule but a standardized complex of low-molecular-weight peptides (reported below roughly 10 kDa) isolated from thymus tissue. In the peptide-bioregulator model advanced by the Khavinson group, these short peptides are proposed to act as signaling molecules that the aging thymus can no longer produce in sufficient quantity. At the molecular level, the peptide fractions are reported to interact with double-stranded DNA and histone proteins and to modulate the expression of genes involved in immune-cell differentiation. Reported downstream effects include supporting T-lymphocyte maturation, restoring interleukin-2 (IL-2) production, and influencing calcium-driven activation cascades in thymocytes and macrophages. Because Thymalin is a mixture rather than a defined single peptide, its pharmacology is less precisely characterized than that of synthetic single-sequence peptides such as thymosin alpha-1. Thymalin's identity also differs in kind from the defined peptides beside it in this library, and the difference is visible in the public chemical registries rather than a matter of opinion. Thymosin alpha-1 is a single 28-amino-acid sequence registered as thymalfasin (PubChem CID 16130571, C129H215N33O55, 3108.3 g/mol). Thymulin is a single nonapeptide (PubChem CID 3085284, C33H54N12O15, 858.9 g/mol, CAS 63958-90-7). Thymalin has no molecular formula in either database: searching PubChem for its own CAS number, 79621-14-0, returns no compound record at all, and the MeSH entry for the neighbouring thymarin concept carries the National Library of Medicine's own note that the registry number refers to a compound of unknown molecular formula. A preparation standardized by biological activity is therefore a different kind of object from a peptide defined by its sequence, and the characterization a buyer can ask for differs accordingly.
Researched effects
Reported effects in the Russian clinical literature include restoration of T-cell counts and CD4/CD8 balance in older or immunocompromised subjects, increased natural killer (NK) cell activity, normalization of cytokine signaling, and reduced frequency of respiratory infections. The widely repeated claim that Thymalin extends life comes from a single publication (Khavinson and Morozov, Neuro Endocrinology Letters, 2004; PubMed 14523363): 266 people over 60, followed for 6-8 years, with the preparations given only during the first 2-3 years, reporting mortality 2.0-2.1 times lower in the Thymalin group than in the control and acute respiratory disease 2.0-2.4 times less frequent. That paper is indexed as a randomized controlled trial, yet its abstract states no confidence interval, no p-value, no method of randomization and no blinding; it comes from the institutes that developed the preparation; no study of Thymalin is registered on ClinicalTrials.gov; and it has never been independently replicated. One detail in it is routinely misread, including in an earlier version of this page: the second preparation in that study was Epithalamin, a pineal-gland extract that the National Library of Medicine describes in its own MeSH record as an epiphysial polypeptoid extract. It is not Epithalon, the defined synthetic tetrapeptide alanyl-glutamyl-aspartyl-glycine (PubChem CID 219042, C14H22N4O9, 390.35 g/mol) that is sold under the similar name. A result reported for an extract is not a result for the synthetic peptide named after it. These are reported research findings, not guaranteed outcomes.
Evidence & regulatory status
Evidence: the geroprotective claim rests on one publication (PubMed 14523363, Neuro Endocrinology Letters 2004) - 266 people over 60, 6-8 years of follow-up, preparations given in the first 2-3 years, mortality reported 2.0-2.1 times lower than control in the Thymalin group. It is indexed as a randomized controlled trial and reports no confidence interval, no p-value and no method of randomization or blinding, and it comes from the institutes that developed the preparation. PubMed types 13 records as clinical trials of Thymalin; the other twelve study a hospital indication — tuberculosis, dysentery, erysipelas, ulcerative colitis, peritonitis, pancreatitis, parkinsonism, schizophrenia and others — so nothing in that set repeats the ageing result.
Registration: ClinicalTrials.gov returns no studies for Thymalin (checked 2026-09-19; the same search for the phrase thymic peptide returns 65 studies, so the query itself works). The US FDA drug-label database returns no label for Thymalin.
Regulatory: reported as registered in Russia as an immunomodulatory medicine. That entry could not be verified in the Russian state register directly, so it is stated here as reported rather than confirmed. Not approved by the FDA or the EMA.
Research use: in the US and most Western markets Thymalin is sold strictly as a research-use-only chemical, not for human consumption or clinical use.
Research timeline
Dated milestones taken from the primary records: the molecule's discovery, its first registered human study, the trials that shaped the evidence and the regulatory decisions. Each entry links to the record it comes from.
Khavinson and Morozov present thymalin as a new immunoregulating preparation, with experimental and clinical results, in the Soviet military medical journal; the PubMed record carries no abstract. PMID 7048731
A report in a Soviet psychiatry journal adds thymalin to psychotropic drugs in 36 patients with treatment-resistant schizophrenia and immune abnormalities and describes improvement; the abstract describes no control group. PMID 2163147
A comparison in 50 patients with ulcerative colitis finds corticosteroids more effective in active, destructive inflammation and thymus preparations such as thymalin preferable only in milder disease. PMID 1441366
A before-and-after report in 15 patients aged 45 to 72 with early Parkinson's disease describes better symptoms and EEG changes after a course of thymalin, with no comparison group. PMID 10424021
Thymalin's developers report that among 266 older people followed for 6 to 8 years, mortality in the thymalin group was about half that of controls; the abstract does not say how the groups were formed. PMID 14523363
Khavinson's institute reports that thymalin shifted human blood-forming stem cells in culture towards mature CD28-positive T cells, and proposes it for COVID-19 prevention on that basis alone. PMID 33237528
Khavinson's institute and a St Petersburg city hospital add thymalin to standard care in COVID-19 patients and report a faster fall in IL-6, C-reactive protein and D-dimer than with standard care alone; the abstract gives no patient numbers and describes no randomisation. PMID 33575961
The institute names two dipeptides, KE and EW, as thymalin's active substances and reports that thymalin and both dipeptides reduced inflammatory cytokines in blood cells from four donors, alongside computer docking to DNA. PMID 37686182
Records checked Oct 5, 2026
Claims at a glance
The claims most often made about this compound, each with the strongest kind of evidence we found for it. The grade says what was studied, not whether the claim is true; the line beside it says what that study showed.
Extends life in older peopleHuman, non-randomised. In one study of 266 older people followed for six to eight years, the developers report deaths about halved in the thymalin group against controls; no randomisation, blinding or confidence interval is described, and no other group has repeated it. PMID 14523363
Strengthens the immune response to serious infectionHuman, non-randomised. Added to drug treatment in 60 hospital patients with tuberculosis, the authors report shorter stays and better results; the abstract gives no figures. PMID 2080155
Helps Parkinson's diseaseHuman, non-randomised. Fifteen patients with early parkinsonism were assessed before and after a course, with no control group; the author reports less tremor, rigidity and slowness. PMID 10424021
Calms inflammatory bowel diseaseHuman, non-randomised. Compared with steroids in 50 people with ulcerative colitis, steroids worked better where inflammation was severe; thymus preparations did better only in milder disease. PMID 1441366
Helps recovery from COVID-19Human, non-randomised. Added to standard care, inflammation and clotting markers in the blood fell faster than in controls; the report measured blood tests rather than recovery and gives no patient numbers in its abstract. PMID 33575961
The reasoning behind each grade, study by study, is in this guide's Benefit & Outcome Review.
Grades checked Oct 7, 2026
A printable reference sheet with the compound's key facts, storage guidance and a vial record comes with All-Access Lifetime.
Half-life & pharmacokinetics
No published pharmacokinetic study establishes a plasma half-life for Thymalin, and that is structural rather than an oversight: a half-life is a property of a molecule, while Thymalin is a mixture whose composition is set by the extraction process rather than by a sequence. Searches of PubMed on the name and of ClinicalTrials.gov, which returns no registered study of Thymalin at all, surface no measured elimination curve, and the figures that circulate in community write-ups are not traceable to a published measurement. Where a number is wanted for comparison, it has to come from a defined peptide such as thymosin alpha-1, which is a single sequence and has been studied as one. Any half-life quoted for Thymalin itself should be treated as an assumption until the measurement behind it can be named.
Reported side effects & toxicology
Reported tolerability in the Russian literature is generally described as good, with the most commonly noted effects being injection-site reactions (redness, soreness) and occasional allergic-type responses, consistent with an animal-tissue-derived product. Because Thymalin is an immunomodulator, the theoretical concerns raised are unpredictable effects in autoimmune conditions and during immunosuppressive therapy. Human safety data outside older Russian studies is limited, and long-term controlled safety data under modern Western standards is lacking. This is not a complete safety profile and not medical advice.
Storage & handling
Lyophilized (powder): store in a freezer or refrigerator, protected from light; the dry powder is reported to remain stable for extended periods when kept cold and sealed.
Reconstituted (in bacteriostatic water): keep refrigerated (about 2-8 C) and use within roughly 2-4 weeks; do not freeze the reconstituted solution.
References
Primary sources for the statements above: Khavinson VKh and Morozov VG, Peptides of pineal gland and thymus prolong human life, Neuro Endocrinology Letters 2004 (PubMed 14523363); the PubChem compound records CID 3085284 (thymulin / nonathymulin), CID 219042 (epithalon) and CID 16130571 (thymalfasin); the National Library of Medicine MeSH records for epithalamin and thymarin; and ClinicalTrials.gov together with the openFDA drug-label API, both queried on 2026-09-19 with the results reported above. Everything here is educational information about reported research, not medical advice.
Evidence File
The Thymalin Evidence File: 302 Papers, 260 of Them in Russian, and One Study Carrying the Entire Longevity Claim
Thymalin has the largest published literature of any compound in this library, and the least readable. PubMed indexes 302 records once every spelling of the name is searched and the results are combined. Of those, 260 are in Russian, nine in Ukrainian and 32 in English — so a reader working in English sees about one paper in nine. The median year of publication is 1990, and more than half of the corpus appeared before the Soviet Union ended. Thirteen records are typed as clinical trials, twelve of them in a language most buyers cannot read. No study of this preparation is registered on ClinicalTrials.gov under any of its names. This file assembles the corpus by hand, says what each part of it can support, and identifies the single 2003 paper that every longevity claim traces back to.
302 records in the corpus, 260 of them in Russian
32 records an English-only reader can read — about one in nine
13 trial-typed records, and 0 of their abstracts report a confidence interval
0 registered studies, under any name, anywhere
How large this literature really is, and why almost nobody reads it
The median year is 1990, and that is the most important number here
202 papers tagged Humans, 13 typed as trials, and the difference between them
The thirteen trials, and what they were actually about
The one paper the longevity claim rests on, read closely
The registry check, and the COVID-19 papers an English search returns first
What has never been measured
7 more sections in the Evidence File for Thymalin
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Thymalin for $14 — or every compound in the library, plus the printable reference sheets, for $99.
The sections above this one stay free to read without an account.
Sourcing File
The Thymalin Sourcing File: A Substance With No Molecular Formula, Two CAS Numbers, and a PubChem Page That Hands You a Different Molecule
Every other sourcing file in this library opens with a molecular formula and a monoisotopic mass. This one cannot, and that is the point. Thymalin is an extract of calf thymus, not a synthesised sequence, and the registry that indexes it records no molecular formula for it at all — the National Library of Medicine's own note on the neighbouring concept states that the registry number refers to a compound with unknown molecular formula and may be the same substance as thymalin. Meanwhile, searching PubChem for the name returns a tidy, confident record for a nonapeptide called thymulin, a different compound this library also sells, whose synonym list carries the word Thymalin. The most useful thing a buyer can take from this file is a single test: a certificate of analysis that prints a molecular formula or a mass near 859 daltons for thymalin is describing a different substance.
0 molecular formulas on record for this substance
2 CAS numbers the registry itself cannot reconcile
858.9 Da — the mass PubChem returns for the name, belonging to a different compound
2 active dipeptides named by the developers, each a separately named preparation
What the registry actually records, in its own words
The PubChem trap, and how to turn it into a test you can run
The two dipeptides the developers themselves name as the active substances
Why a certificate of analysis means something different for an extract
What to ask a supplier, in the order to read it
5 more sections in the Sourcing File for Thymalin
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Thymalin for $14 — or every compound in the library, plus the printable reference sheets, for $99.
The sections above this one stay free to read without an account.
Benefit & Outcome Review
The Thymalin Benefit & Outcome Review: Thirteen Trials, and Twelve of Them Were About Something Else
Thymalin is bought today for immune support and for ageing. Its trial literature is about dysentery, erysipelas, tuberculosis, schizophrenia, ulcerative colitis, peritonitis in children, Parkinson's disease and pancreatitis — Soviet and post-Soviet hospital medicine, in which the preparation was almost always added on top of the treatment the patient was already receiving. Of thirteen trial-typed records, twelve studied a hospital indication and one studied ageing. This review takes each claimed benefit in turn, reports what was measured and in how many people, keeps patient results apart from laboratory results, and is explicit about the two design features that limit what any of it can prove: the add-on structure, and the absence of a single confidence interval across all thirteen abstracts.
13 trial-typed records; 1 of them studied ageing
266 people in the single geroprotection study, observed 6 to 8 years
8 of the 13 describe the peptide as an add-on to another treatment
0 confidence intervals across all 13 abstracts; 1 p-value
How to read a benefit review built on add-on trials
The ageing and longevity claim: one study, and what it actually reports
The immune and infection claims, which is where the patient data actually is
The neurological and inflammatory-bowel claims, and one honest negative
What no benefit claim here can rest on
5 more sections in the Benefit & Outcome Review for Thymalin
Unlock the Evidence File, Sourcing File and Benefit & Outcome Review for Thymalin for $14 — or every compound in the library, plus the printable reference sheets, for $99.
Quick answers about guide scope, access, and educational use context.
Is Thymalin the same as Thymosin Alpha-1 or Thymulin?
No. Thymalin is a complex mixture of several low-molecular-weight peptides extracted from thymus tissue. Thymosin alpha-1 is a single defined 28-amino-acid synthetic peptide, and Thymulin is a separate defined nonapeptide. They are related in origin and target but are distinct compounds with different characterization.
Is Thymalin approved by the FDA?
No. Thymalin is registered as an immunomodulatory medicine in Russia but is not approved by the FDA or EMA. In the US it is sold only as a research-use-only chemical, not for human use, and it has not been evaluated by US regulators for safety or efficacy.
Why is Thymalin measured in milligrams rather than mcg?
Thymalin is a polypeptide extract handled at the milligram scale, unlike many synthetic peptides handled in micrograms, so its vials and certificates state content in milligrams. This page does not publish dose or reconstitution arithmetic.
How long is a typical reported course?
Reported protocols commonly describe 5-10 consecutive days of once-daily injection making up one course, with courses repeated roughly every 3-6 months rather than run continuously. This reflects the reported model of short intermittent bioregulator courses.
Is Thymalin banned in sport?
Thymalin is not named individually on the WADA Prohibited List, but as a non-approved substance it can fall under the catch-all S0 category (substances not approved for human use), which WADA treats as prohibited at all times. Athletes should not assume it is permitted.
Does Thymalin extend lifespan?
That claim traces to one publication (PubMed 14523363): 266 people over 60 followed for 6-8 years, reporting mortality 2.0-2.1 times lower in the Thymalin group. It reports no confidence interval and no p-value, gives no randomization or blinding method, was written by the institutes that developed the preparation, is not registered on ClinicalTrials.gov, and has not been independently replicated in the two decades since. It is one result under those conditions, not an established effect.
Why does a chemical database return a different compound when I search for Thymalin?
Because the two names are filed together. A PubChem search on Thymalin returns CID 3085284, a complete record with the formula C33H54N12O15 and a mass of 858.9 - but that record is Thymulin (nonathymulin, CAS 63958-90-7), a different nonapeptide, returned because its synonym list carries the string Thymalin. Thymalin's own CAS number, 79621-14-0, returns no compound record at all, and MeSH records no molecular formula for it. A figure of that kind presented as Thymalin's is describing the other compound.
Is Epithalon the same as the Epithalamin used in the longevity study?
No, and the difference matters when reading that study. Epithalamin is a pineal-gland extract - the National Library of Medicine's MeSH record calls it an epiphysial polypeptoid extract. Epithalon is the defined synthetic tetrapeptide alanyl-glutamyl-aspartyl-glycine (PubChem CID 219042, C14H22N4O9, 390.35 g/mol). The 2004 study administered the extract; results reported for it are not results for the synthetic peptide named after it.
Compliance and trust notes
Educational content only; no personalized health or outcome claims.
No personalized use recommendation outputs.
Use this material for general learning and research-context literacy.
A certificate of analysis (COA) is a laboratory’s report on one sample of one batch. The single most useful thing to know about it is that purity and identity are two separate results that fail in different ways. A high purity figure says the sample was mostly one substance; it does not say that substance was Thymalin. Identity — normally a mass-spectrometry result matching the expected molecular weight — is what establishes what the material actually is, and a certificate reporting purity alone has not answered that question.
Two further limits are worth holding onto. Mass per vial is its own test: a vial can be 99% pure and still contain less material than the label claims. And sterility, endotoxin, heavy metals and residual solvent screening are separately commissioned tests, usually priced individually — so a “third-party tested” badge asserts none of them unless the certificate names them. Check that the batch or lot number on the document matches the vial in front of you; an unmatched certificate describes someone else’s material.
Medibact does not test, endorse or resell peptides, and publishes no rating of any laboratory. How to read a peptide certificate of analysis walks through the document section by section, and what each COA field establishes covers the field-by-field detail and the laboratories that publish their methods.
You’ll need bacteriostatic water
The diluent for reconstituting Thymalin
Reconstitution is volume arithmetic — it assumes a lyophilized vial is dissolved in bacteriostatic water, which is sterile water preserved with 0.9% benzyl alcohol. The preservative is what allows a vial to be entered more than once; plain sterile water carries none and is single-entry by design. Medibact supplies USP-grade Bacteriostatic Water for Injection in a 30 mL multi-dose vial, made in the United States and shipped from the United States, for research use only. One 30 mL vial covers 30 reconstitutions at 1 mL each, 15 at 2 mL, or 10 at 3 mL — division only, not a dosing recommendation.
Educational use only — not medical advice. This guide summarizes information reported in published research and community practice for educational purposes. It is not medical advice and not a recommendation to use any compound. Any doses, schedules, or combinations shown are examples of what has been reported, not instructions for you. Many peptides described here are research compounds that are not FDA-approved for the uses discussed and may be investigational or restricted. Effects, risks, and legal status vary; individual needs and results vary. Consult a qualified, licensed healthcare professional before making any decision. Do not use this content to diagnose, treat, or dose yourself.
