What is thymogen?
Thymogen is the dipeptide L-glutamyl-L-tryptophan (Glu-Trp, often written EW). V. G. Morozov, V. Kh. Khavinson and colleagues, later of the Saint Petersburg Institute of Bioregulation and Gerontology, isolated it from the calf thymus extract thymalin by reversed-phase chromatography, then built a pharmaceutical on the synthesized dipeptide (Morozov and Khavinson, 1997) that later took the brand name Thymogen (Anisimov et al., 2000).
Its international nonproprietary name is oglufanide: WHO published it in Proposed INN List 86 (WHO Drug Information, 2002) as L-α-glutamyl-L-tryptophan, an immunomodulator. Outside Russia, it was developed under the code IM862 as an angiogenesis inhibitor and tested in US and UK cancer trials (Deplanque et al., 2004; Noy et al., 2005).
About 100 PubMed records name thymogen, oglufanide or IM862 in the title or abstract. About three quarters are in Russian or Ukrainian, more than half predate 2000, and only about one in seven lists Khavinson or Morozov as an author. The English-language record is led by the IM862 trials, and the two placebo-controlled ones found it no better than placebo.
Thymogen is not an approved drug in the United States (Drugs@FDA, via openFDA, October 2026). Disguised Alpha does not currently list thymogen; this page is a literature reference for laboratory researchers. Nothing on this page is guidance for use in people.
Thymogen reference data
| Property | Value |
|---|---|
| Name | Thymogen |
| Also called | Oglufanide (INN), Glu-Trp, EW dipeptide, L-α-glutamyl-L-tryptophan, timogen; IM862, the development code (PubChem files it under the disodium salt, oglufanide disodium) |
| Sequence | Glu-Trp (EW), written H-Glu-Trp-OH: L-glutamic acid joined through its α-carboxyl to L-tryptophan, with free amino and carboxyl ends |
| Compound class | Synthetic dipeptide; an immunomodulator in its WHO INN entry; a thymus-series "peptide bioregulator" in its developers' terms |
| Molecular formula | C₁₆H₁₉N₃O₅ (free acid); C₁₆H₁₇N₃Na₂O₅ (disodium salt) |
| Molecular weight | 333.34 g/mol (free acid); 377.30 g/mol (disodium salt) |
| PubChem CID | 100094 (free acid); 158780 (disodium salt) |
Values are from PubChem CID 100094 (titled Thymogen; its names include oglufanide, Glu-Trp and EW dipeptide) and CID 158780 (IM862, oglufanide disodium). The WHO INN entry gives the same formula. Do not confuse thymogen with golotimod (SCV-07, PubChem CID 6992140), in which D-glutamic acid is linked through its side-chain carboxyl to L-tryptophan.
What the research covers
The English-language work summarized here falls into five areas; the Russian-language reports are not reviewed one by one. Each summary names the model.
Immune cells in culture
The developers' 1997 overview reported, without naming the model in its abstract, that the synthetic dipeptides activated T-cell differentiation, neutrophil chemotaxis and phagocytosis (Morozov and Khavinson, 1997). In the human THP-1 monocytic cell line, thymogen was one of five of the group's peptides that raised tyrosine phosphorylation of mitogen-activated kinases and lowered lipopolysaccharide-stimulated TNF and IL-6 expression (Avolio et al., 2022).
In lipopolysaccharide-stimulated blood mononuclear cells from four donors, EW lowered TNF-α release about fivefold but did not significantly change IL-1β or IL-6; thymalin and the dipeptide KE were tested alongside, and docking placed EW on the DNA sequence GGAG (Linkova et al., 2023). Models: human cell lines and donor cells.
Lifespan and spontaneous tumors in rats
Seventy-six five-month-old outbred female rats were randomly assigned to saline or L-Glu-L-Trp five times a week for 12 months and followed to natural death. Mean lifespan did not differ. The longest-lived tenth of treated rats lived longer, 1,048 against 949 days, and total tumors were 1.5 times, malignant tumors 1.7 times and leukemias and lymphomas 3.4 times less frequent than in controls (Anisimov et al., 2000). Model: female rats.
Angiogenesis models
An independent group at TU Dresden screened four tryptophan-containing dipeptides on VEGFR-2 signalling, where WL had the strongest effects, then compared WL with EW. Of the two, only EW significantly inhibited sprouting in a three-dimensional fibrin gel bead assay.
EW and the dipeptide WL both reduced vessel sprouting from mouse aortic rings and vessel numbers in a VEGF-stimulated chick chorioallantoic membrane assay, and both nearly abolished the VEGF-driven rise in hemoglobin in matrigel plugs. The authors named WL, not EW, as the candidate worth pursuing (Khedr et al., 2021). Models: cell assays, mouse aortic rings, chick embryos and mice.
Cancer trials of IM862
A phase II study without a placebo arm randomized 44 people with AIDS-related Kaposi sarcoma to two schedules and reported major responses in 36 percent (Tulpule et al., 2000). The randomized, double-blind phase III trial that followed enrolled 202 HIV-positive people, 104 on IM862 and 98 on placebo.
Response rates were 23 and 21 percent, not a significant difference, and median time to progression was shorter on IM862, 16 against 35 weeks. The authors concluded it was not superior to placebo and that antiretroviral therapy alone may have contributed to earlier response estimates (Noy et al., 2005).
In 25 people with metastatic renal cell carcinoma, an Oxford phase II study saw no objective responses, though plasma VEGF fell (Deplanque et al., 2004). In men with rising PSA after prostate cancer surgery or radiation, randomized double-blind to IM862 or placebo in the third month of a three-month androgen ablation course and continued for 6 months into the interval off ablation, progression at 6 months was 41 and 49 percent among 71 evaluable men, not a significant difference (Mao et al., 2007).
Chemistry, delivery and isomers
Glu-Trp is highly hydrophilic and crosses membranes poorly. A University of Queensland group made eleven lipid conjugates of its amide, Glu-Trp-NH2, several of which resisted proteolytic enzymes better and crossed Caco-2 cell monolayers more readily (Bergeon and Toth, 2007). Chirality matters: a 2024 review contrasts thymogen, L-Glu-L-Trp, with thymodepressin, built from D-glutamic acid and D-tryptophan, which suppressed rather than stimulated immune responses (Deigin et al., 2024). Models: enzyme extracts, Caco-2 cells and a review.
Key studies
- Anisimov VN, et al. "Immunomodulatory synthetic dipeptide L-Glu-L-Trp slows down aging and inhibits spontaneous carcinogenesis in rats." Biogerontology. 2000. PMID 11707921. DOI 10.1023/a:1010042008969. Female rats followed to natural death.
- Deplanque G, et al. "Phase II trial of the antiangiogenic agent IM862 in metastatic renal cell carcinoma." Br J Cancer. 2004. PMID 15354209. DOI 10.1038/sj.bjc.6602126. Single-arm phase II.
- Noy A, et al. "Angiogenesis inhibitor IM862 is ineffective against AIDS-Kaposi's sarcoma in a phase III trial, but demonstrates sustained, potent effect of highly active antiretroviral therapy: from the AIDS Malignancy Consortium and IM862 Study Team." J Clin Oncol. 2005. PMID 15598977. DOI 10.1200/JCO.2005.11.043. Placebo-controlled phase III.
- Khedr S, et al. "Characterization of tryptophan-containing dipeptides for anti-angiogenic effects." Acta Physiol (Oxf). 2021. PMID 32894635. DOI 10.1111/apha.13556. Independent angiogenesis assays.
- Avolio F, et al. "Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line." Int J Mol Sci. 2022. PMID 35408963. DOI 10.3390/ijms23073607. Human THP-1 cells.
Handling and storage of lyophilized thymogen
General laboratory practice for a lyophilized dipeptide, in line with the site's peptide storage guide and reconstitution guide:
- Keep the sealed powder at -20°C, dry and dark; the tryptophan indole ring is prone to photo-oxidation. Let a cold vial reach room temperature before opening.
- The dipeptide is hydrophilic, so water or an aqueous buffer is the usual first diluent. Test a small portion and record the pH.
- Check whether the material is the free acid (333.34 g/mol) or the disodium salt (377.30 g/mol) before calculating molarity.
- Store solutions at 2 to 8°C, protected from light, in single-use aliquots; avoid repeated freeze and thaw cycles.
Frequently asked questions
What is thymogen?
The dipeptide Glu-Trp, isolated from the calf thymus extract thymalin (Morozov and Khavinson, 1997), studied as an immunomodulator in Russia and, as IM862, as an angiogenesis inhibitor in Western cancer trials.
Is the thymogen peptide the same as oglufanide and IM862?
Yes, the same dipeptide. Oglufanide is its INN, and IM862 is the development code, which PubChem files under the disodium salt (CID 158780). It is not the same as thymodepressin, a D-amino acid isomer with the opposite immune activity (Deigin et al., 2024), or golotimod.
Has thymogen been tested in people?
Yes. PubMed holds dozens of Russian-language clinical and experimental reports, mostly from the 1990s. Under the IM862 code it went through US and UK cancer trials, and the placebo-controlled ones found it no better than placebo (Noy et al., 2005; Mao et al., 2007).
Is thymogen an approved drug?
Not in the United States. Drugs@FDA has no record of it, and the FDA orphan-drug record for L-glutamyl-L-tryptophan shows a 1999 designation for AIDS-related Kaposi's sarcoma that is "Not FDA Approved for Orphan Indication". In Russia it was developed as a pharmaceutical under the Thymogen brand (Anisimov et al., 2000).
How does thymogen relate to thymalin and vilon?
Same thymus program: thymalin is the extract Glu-Trp was isolated from, and vilon is another synthetic immunomodulatory dipeptide from the same group (Morozov and Khavinson, 1997), Lys-Glu (Avolio et al., 2022). See our thymalin research guide.
Does Disguised Alpha sell thymogen?
Not currently. Related bioregulators in the catalog include Thymalin, Epitalon and Vesugen.
Related compounds and guides
- Peptide bioregulators A to Z
- Peptide bioregulators explained
- Thymic peptides explained
- Thymalin research guide
- Epitalon research guide
- Vesugen research guide
Literature reference for laboratory research only.