Immune & ThymicTarget: ThymusImmune

Thymogen

Glu-Trp · EW dipeptide · α-glutamyl-tryptophan · Тимоген

Thymogen is synthetic Glu-Trp (EW, α-glutamyl-tryptophan) - an immune dipeptide with a real CIS pharmaceutical footprint (intranasal drops in Russian practice). It is not Thymulin (the zinc nonapeptide FTS) and not Thymalin (extract).

Not FDA-approved - research chemical
Reviewed by CalcMyPeptide Editorial Team
Last updated: August 2026Evidence: Low4 peer-reviewed citations
Typical research dose
100-1000 mcg/day (intranasal or SC)
Frequency
1× daily for 3-10 days
Half-life
Short (dipeptide)
Common vials
1 mg / 5 mg
CAS
79738-25-3
Molecular weight
337.34 g/mol

Use-case scores

0–10 against the evidence we have, not a gym ranking. Hidden domains do not apply here.

  • Longevity / aging3.5/10

    Khavinson-school tissue peptide. Single-lab concentration after haircut. Not a Western Phase 3 geroprotector.

  • Immune3.5/10

    Thymus/immune organ map in the school. Not Zadaxin and not a US immune-deficiency drug.

Compound card

Sequence
EW
Class
Khavinson cytogen (EW)
Formula
C16H19N3O5
Status
Not FDA-approved · research use
Dose it
1 mg + 1 mL BAC water → 1 mg/mL · 100 mcg ≈ 10 units (U-100)
Open in calculator

How it works

Thymogen (Glu-Trp) is a synthetic dipeptide thymic bioregulator developed by Vladimir Khavinson. It restores T-cell differentiation, NK cell activity, and immune-endocrine balance. Clinical studies show improved immune response in elderly patients and reduced immune senescence markers.

Source: PMID: 15677927

Khavinson map

Canonical 41
Class
Cytogen (synthetic short peptide)
Organ
Thymus / immune
Target
Thymus
System
Immune
Sequence
EW · Glu-Trp
Тимоген

Used in bioregulator stacks

Manufacturer-style organ combinations - not FDA protocols. Every name is a live leaf.

The Khavinson school

Vladimir Khatskelevich Khavinson (1946–2024) spent five decades at what became the St. Petersburg Institute of Bioregulation and Gerontology arguing a simple, stubborn idea: aging is, in part, a failure of tissue-specific peptide signals, and those signals can be restored. The first products were not “peptides” in the Instagram sense. They were Cytamins - polypeptide fractions isolated from a named organ of young animals. Later commercial refinements of those fractions are sold as Cytomaxes (Cytomed / NPCRIZ): still mixtures, still oral capsules, still defined by the source organ rather than a single sequence. When the group identified short active motifs inside those mixtures, they synthesized them as Cytogens - di-, tri-, and tetrapeptides with a one-letter code (KE, AEDG, KED, EDR, KEDP, and so on).

That three-layer stack is the whole map. Cytamin / pharmaceutical extracts (Thymalin, Epithalamin, Cortexin, Retinalamin, Prostatilen) are the clinic-era injectables registered in the former Soviet pharmacopeia. Cytomaxes are the capsule complexes Cytomed still lists as a 21-SKU organ line. Cytogens are the defined synthetics. English-language educators, including Brenden Henry’s public writing at Peptide Science Institute, add a further commercial distinction - later analog SKUs (N-acetyl, amidate, “V2” complexes) sold as more stable or more diverse than the original Cytomed lots. That last layer is a product taxonomy, not a Khavinson paper. We describe it so readers are not gaslit by three bottles with the same organ name. We do not reproduce paid Peptide Mastery protocols, Precision Cell Method language, or anyone else’s course IP.

Full Cytamin → Cytomax → Cytogen map, literature limits, and how we counted 41

The mechanism Khavinson published is epigenetic, not receptor-agonist in the GLP-1 sense. Short peptides are claimed to enter nuclei, interact with DNA/histones, and reopen tissue-specific transcription that condensed with age (heterochromatin → euchromatin). Reviews in the Bulletin of Experimental Biology and Medicine and Neuroendocrinology Letters (PMID 14523363, 15677927, 23888677) are the citable core. Complementary GI pharmacology is not mystical: di- and tripeptides are PEPT1/LAT substrates, which is why oral capsules are even a conversation. What is not established in Western Phase 3 programs is organ-by-organ disease treatment, telomere reversal as a clinical endpoint, or the manufacturer claim that Cytomax is “a third stronger” than Cytogen. Those are NPCRIZ marketing sentences.

Khavinson’s group published hundreds of papers, many in Russian, many in the same journal family. That is a real literature. It is also a literature with limited independent Western replication, small n, and a habit of using one review PMID as a stamp on every organ. On this site a leaf earns its organ story, its Cytomax↔Cytogen pair, its sequence if it has one, and an honest sentence about what has not been shown. Reconstitution math belongs on cytogens sold as vials. Cytomax capsules do not get a fake 5 mg vial.

The 41 we treat as canonical are the 21 Cytomaxes on the public e-peptide/Cytomed list, the 12 Cytogens on that same commercial line (including Vesilut, which Western catalogs often drop), plus eight historically load-bearing molecules that sit beside the capsule SKUs: Epitalon, Vilon, Thymogen, Livagen, Cortagen, Prostamax, Thymalin, and Epithalamin. Honluten, Cortexin, Retinalamin, Prostatilen, Thymulin, N-acetyl-epitalon-amidate, Pinalex, and the GPL Man / GPL Femme kits are covered as adjacent - same school or same storefront, not padded into a fake 41.

Public English-language teaching (including Brenden Henry at peptidescienceinstitute.com) is cited as context, not copied. Paid Peptide Mastery / Peptide Salvation text stays theirs.

History of this molecule

EW is one of the few Khavinson-adjacent dipeptides that behaved like a drug product (immunomodulator drops) rather than only a research-chem vial. That does not make it FDA-approved in the US. It does mean this leaf has a different regulatory texture than Cartalax.

Thymulin (FTS) is a nine-residue zinc-dependent thymic hormone from a French discovery path. Different molecule. Our library keeps both. Do not merge them because the first five letters match.

Vilon is KE. Thymogen is EW. Two dipeptides, one organ aisle.

Caveats

A defined sequence is not an FDA indication. Immune cytogens sit in a Russian experimental-gerontology literature with limited Western replication. “Oral bioavailability because PEPT1” is real peptide-transport biology; it is not proof this SKU treats the organ disease. Gray-market identity is a live problem - HPLC is the only way to know the vial is the sequence on the label.

Full 41-map: Khavinson bioregulators index · Bioregulator stacks

Research Use Cases

  • ✓Secondary immunodeficiency (post-infection, post-surgery)
  • ✓Chronic bacterial and viral infection adjunct
  • ✓Post-radiation immune recovery
  • ✓Seasonal immune support (cold/flu prevention)

Dosing

PhaseDoseFrequencyNotes
Khavinson Protocol1–2 capsules/day or 1–2 mg SCDaily for 10–30 day courses, 1-2x per yearPart of Khavinson thymic complex. Can follow or precede Thymalin. Often combined with Epitalon.

Administration

Route / form
Two real SKUs: Cytomed oral capsules (swallowed) or a lyophilized research vial reconstituted for subcutaneous injection. Nobody manufactures these as sublingual tablets.
Timing
Capsules: morning, about 30 minutes before meals. Research vial (SubQ): food does not change the injection.
Empty stomach?
Capsules: yes - Swallow on an empty stomach, about 30 minutes before meals. Reconstituted vial (SubQ): food does not change the injection. Cytomed boxes sometimes print “with food” because they are labeled as supplements; the manufacturer user-guide preference is before meals.

Thymogen: Cytomed EW capsule vs Research EW vial vs CIS intranasal drops

Cytomed EW capsule
Bioavailability
Cytomed oral EW capsules, swallowed with water. Dipeptides are PEPT1/LAT substrates, which is why a swallowed capsule is even a conversation. That is transporter biology, not a US indication and not proof the organ disease is treated. Intranasal CIS drops are not this capsule.
Dose note
Cytomed folklore: 1–2 capsules daily, 10–30 day courses, morning, about 30 minutes before meals. Manufacturer protocol, not an FDA label.
Advantages
  • Oral cytogen SKU exists. No reconstitution.
  • Dipeptide oral story is stronger than tetrapeptide cytogens.
  • Not a sublingual tablet. Nobody manufactures this SKU that way.
Considerations
  • Vladonix is the thymus Cytomax. Swallowing that kit is not a Thymogen dose.
  • Do not dose capsules from a dropper insert or from a 10 mg Thymalin ampoule.
  • US approval: no. CIS immunomodulator history stays in CIS.
Research EW vial
Bioavailability
Research SubQ from a reconstituted EW (Glu-Trp / α-glutamyl-tryptophan) vial. Not the CIS dropper and not Thymalin IM.
Dose note
Research-vial folklore is short courses around 1–2 mg SC. Do not assume the CIS dropper microgram dose equals this milligram cake. Not a Thymalin 10 mg IM ampoule chart.
Advantages
  • Defined dipeptide. Vial math is legitimate when the bottle is powder.
  • Separable from Thymalin extract and from Thymulin (FTS nonapeptide).
  • Food does not change the shot.
Considerations
  • US research cake ≠ Cytomed capsule ≠ CIS drops. Three bottles, three doses.
  • Not Thymulin. Zinc-dependent FTS biology does not apply to EW.
  • Infection treatment this is not. Keep antivirals/antibiotics in their lane.
CIS intranasal drops
Bioavailability
CIS pharmaceutical glutamyl-tryptophan drops. Real drug-product texture in that market. Not an FDA label, not a Cytomed capsule, and not a sublingual tablet.
Dose note
Dropper labeling is often in the 100–1000 mcg range. Do not equate the dropper to 1–2 mg SC research-chem or to a 10-day Cytomed capsule box.
Advantages
  • This is the presentation that made EW behave like a drug product in CIS practice.
  • Keeps the dropper from being flattened into a US vial protocol.
Considerations
  • CIS immunomodulator history does not transfer as a US BLA.
  • Not Thymalin IM extract and not Thymulin FTS.
  • Not a pneumonia protocol.
Recommendation: Thymogen (EW) is capsule-or-vial, plus a CIS intranasal dropper that is neither of those. Swallow Cytomed capsules, reconstitute a research vial for SubQ, or use the labeled CIS drops - do not mix those dose sheets. It is not Thymalin (extract, IM), not Thymulin (FTS), not Vilon (KE), and not a sublingual tablet. Dropper micrograms are not vial milligrams.

Timeline

Day 1-10 (course)
T-cell and NK cell activity restoration begins.
Month 3-6
Sustained immune biomarker improvement with repeat courses.

Who it is for

Immune Senescence / T-Cell Immunity

Low

Thymic dipeptide. Restores T-cell and NK function. Khavinson protocol component.

Reconstitution

VialWaterConcentrationExample dose
Lyophilized cytogen (if the SKU is a vial)Follow the COA fillDo the mathCapsules skip this step. Cytomax complexes are not this molecule.

Change vial size or water volume? Open the reconstitution calculator.

Safety & Considerations

Research peptide in Western markets. Extensively used in Russian clinical protocols. Russian clinic history is not a US safety NDA.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change - verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Limits of current evidence

  • A defined sequence is not an FDA indication.
  • Gray-market identity is a live problem. HPLC beats a blog table.
  • Do not paste a sibling cytogen’s papers onto this SKU.
  • This site will not treat the named organ disease from a peptide page.

Verdict

Thymogen is the synthetic EW cytogen for Thymus / immune. Khavinson’s group published in this family. That is a concentrated literature, not a Western Phase 3. Capsules and vials are different SKUs.

Interactions & Contraindications

Well tolerated. Intranasal spray form is OTC in Russia - excellent safety profile. Avoid in autoimmune conditions. Standard course: 3-10 days. Can be combined with conventional antibiotics/antivirals for infection management.

Synergies & Common Stacks

Thymogen (mild thymic dipeptide, OTC) can serve as maintenance therapy between Thymosin Alpha-1 cycles (more potent, prescription-level) - graduated immune support.

Thymogen stimulates thymulin production from thymic epithelial cells - the two peptides are mechanistically linked, with Thymogen acting upstream to enhance endogenous thymulin secretion.

Frequently Asked Questions

Thymogen vs Thymalin vs Thymulin vs Vilon?▼
Thymogen = EW dipeptide. Thymalin = thymus extract. Thymulin = zinc nonapeptide FTS. Vilon = KE.
US approved?▼
No. CIS pharmaceutical use does not transfer as an FDA label.
Sequence?▼
Glu-Trp (EW).
Capsule, vial, or drops?▼
Cytomed capsules (swallowed), research vials (SubQ), and CIS intranasal drops are three presentations. Dropper micrograms are not vial milligrams. Not Thymalin IM, not a sublingual tablet.
Infection treatment?▼
Not a substitute for antivirals/antibiotics. Immunomodulator history ≠ a pneumonia protocol.
How does Thymogen differ from Thymalin?▼
Thymalin is a polypeptide thymus extract; Thymogen is a specific synthetic dipeptide (Glu-Trp). Thymogen targets thymic immune axis via known dipeptide sequence. Both are part of the Khavinson immune bioregulator toolkit.

References

  1. Khavinson VKh et al. “Tissue-specific effects of peptides.” Bulletin of Experimental Biology and Medicine (2005). PMID: 15677927
  2. Khavinson VKh, Lin’kova NS, Tarnovskaya SI “Short peptides regulate gene expression.” Bulletin of Experimental Biology and Medicine (2013). PMID: 23888677
  3. Khavinson VKh, Morozov VG “Peptide regulation of aging: from experimental studies to clinical practice.” Advances in Gerontology (2003). PMID: 14523363
  4. Khavinson VKh et al. “"Thymic dipeptide Thymogen modulates neuroendocrine and immune function".” Bulletin of Experimental Biology and Medicine (1997). PMID: 9364573

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Recommended sourceOral bioregulator

Get Thymogen from Vita-Stream - a distributor for Khavinson-line oral capsules. No reconstitution math on a Cytomax bottle.

Affiliate link · Full review