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PeptideLimited humanNot FDA approved

Thymogen

L-glutamyl-L-tryptophan (Glu-Trp dipeptide)

Last reviewed October 27, 2026 · 36 sources · Written for general readers · Compare with another compound →

The bottom line

Thymogen is a two amino acid peptide registered as an immune medicine in Russia.[1] The same molecule, called IM862, was tested in Western cancer trials, and placebo controlled trials in 202 and 71 people found it worked no better than placebo.[2][3] Russian trials report immune and stomach lining benefits, but they are mostly small, and it is not approved in the US.

Where the evidence stands

What it is

Thymogen is a dipeptide, a chain of just two amino acids: glutamic acid and tryptophan. FDA's substance registry lists the same molecule under the drug name oglufanide.[26]

A 2024 review says it was first found in a fraction of thymalin, a calf thymus extract, and is registered with Russia's Ministry of Health.[1] Outside Russia, the same molecule was developed for cancer under the code name IM862, and later as oglufanide for hepatitis C in Australia.[7][27] Recent Russian studies test a nasal spray form of the drug.[10][11]

Name
Thymogen (L-glutamyl-L-tryptophan (Glu-Trp dipeptide))
Other names
Timogen, oglufanide, IM862, EW, Glu-Trp, alpha glutamyl tryptophan
Type
Peptide
Sequence
EW
CAS number
38101-59-6
Formula
C16H19N3O5
Molecular weight
About 333.3 g/mol

What it does in the body

Thymogen is a chain of two amino acids, glutamic acid and tryptophan, first found in thymalin, an extract of calf thymus, the gland where T cells mature.[4][1] It is not a hormone with one known receptor. It is described as an immune tuner, and in mice its tumor fighting effect depended on natural killer cells, a type of immune cell that attacks abnormal cells.[5]

This is the biology, area by area. A change measured in the body, like a higher blood level, does not always mean a person feels a benefit. The claims check below covers that.

Immune system

Measured in people

In blood immune cells in a dish, it pushed T cells to mature, raised the immune signals IL2 and interferon, and boosted neutrophils, the cells that swallow germs.[4] In 48 people with acute pancreatitis, adding Thymogen to usual care was reported to remove a shortfall in T cells compared with 36 healthy donors.[6] These Russian reports did not use a placebo.

Cancer and tumor blood vessels

Measured in people

In mice, the dipeptide slowed tumor growth without poisoning tumor cells directly, and this needed working natural killer cells.[5] In people, IM862 was tested as a blocker of new tumor blood vessels. In a kidney cancer trial, blood levels of VEGF, a signal that drives new blood vessel growth, fell during treatment, but no tumors shrank.[7]

Gut

Measured in people

In a Russian placebo controlled trial of 116 people with long term stomach lining damage linked to H. pylori bacteria, the number of stomach glands rose 26.1% in the treated group.[8] Camera exams in 80 of these patients showed less swelling and inflammation of the stomach lining.[9]

Lungs and infections

Seen in animals

In mice with deadly flu pneumonia, using the nasal spray before infection lowered virus in the lungs about 32 times on day 3 and about 16 times on day 6 compared with untreated mice.[10] In cells in a dish, the spray was active against RSV, parainfluenza virus and the virus that causes COVID 19.[11][12] No controlled human trial has tested this.

Heart and blood vessels

Seen in animals

In an isolated heart model, Thymogen protected heart muscle starved of blood better than two comparison drugs, and in rat and guinea pig models it was reported to calm abnormal heart rhythms.[13][14] These are older Russian lab and animal studies without numbers.

Skin and hair

Lab finding

In human skin cells grown in a dish, Glu-Trp raised Ki67, a marker of cell renewal, and lowered caspase 9, a protein that drives cell death.[15]

Absorption

Lab finding

The plain dipeptide passes poorly through cell membranes, which is why researchers tried attaching fat or sugar groups to help it be absorbed by mouth.[16] Trials have given it as a nasal spray or injection.[17][18]

How it works

Thymogen is said to tune the immune system, and IM862 was tested as a drug to block new blood vessel growth in tumors.

  • The 2024 review says it helps restore white blood cells and T cells, a key type of immune cell, after chemotherapy.[1]
  • In mice, its tumor slowing effect was lost in animals lacking working natural killer cells or perforin, a protein these cells use to kill, and was weaker in mice lacking IL12.[5]
  • In a human immune cell line grown in a dish, it lowered inflammation signals and made cells stick less to blood vessel cells.[28]
  • In blood immune cells from four donors, EW lowered the inflammation signals IL1 beta, IL6 and TNF by 1.4 to 6 times after a bacterial trigger, and computer models predicted it binds a short DNA stretch.[23]
  • In a cancer trial, blood levels of VEGF, a signal that drives new blood vessel growth, fell during treatment.[7]

How it might work in people is not settled, and the immune theory rests mostly on Russian lab and small clinical work.

What the research shows

We keep animal and human evidence apart. A result in animals is a reason to study something in people, not proof that it works in people.

Animal and lab studies

Older Russian animal studies, one US mouse study and lab work

  • In 76 female rats followed until natural death, the dipeptide did not change average lifespan but lengthened the life of the longest lived rats and cut total tumors 1.5 times and blood cancers 3.4 times.[25]
  • In a US mouse study, the dipeptide slowed tumor growth only when natural killer cells worked.[5]
  • In rats given a chemical that causes throat and stomach tumors, Thymogen lowered how often and how many tumors formed.[29]
  • In mice infected with deadly flu, groups of 30 mice each compared the nasal spray with Tamiflu and an antiseptic spray. Using Thymogen before infection gave lung tissue close to normal, as did Tamiflu, and cut lung virus about 32 times by day 3.[10]
  • In an older mouse flu study, Thymogen injected into the belly was less effective than the flu drug rimantadine, while a mix with glycyrrhizic acid cut deaths by 75% to 79% compared with untreated mice.[22]
  • In isolated hearts and in rat and guinea pig models, it protected heart muscle starved of blood and calmed abnormal rhythms, without numbers in the summaries.[13][14]
  • In a human immune cell line, it had the strongest effect of five Khavinson peptides at reducing immune cell sticking, and it most strongly cut the inflammation signal IL17.[28]

Limit: Most animal work is decades old, published in Russian, and comes from groups tied to the developers.

Human studies

Negative Western cancer trials and small Russian studies

  • In an early study of 44 people with HIV and Kaposi sarcoma, a skin and tissue cancer, IM862 nose drops were followed by tumor shrinkage in 36%, with 5 complete and 11 partial responses. There was no placebo group.[17]
  • A later placebo controlled trial of 202 people with the same cancer found tumors shrank about as often with IM862 as with placebo, and the cancer got worse sooner on IM862, at 16 versus 35 weeks.[2]
  • In a double blind trial of 71 men with prostate cancer, IM862 nasal spray did not slow the rise of PSA, a prostate cancer blood marker. At six months, the cancer had progressed, judged mainly by a rising PSA, in 41% of men on IM862 and 49% on placebo, a difference that could be chance. No significant side effects appeared.[3]
  • In 25 people with advanced kidney cancer, no tumors shrank. Side effects were mostly mild headaches and sinus irritation, and one person's bowel disease flared.[7]
  • In a Russian double blind, placebo controlled trial of 116 people with long term stomach lining damage linked to H. pylori bacteria, the number of stomach glands rose 26.1% in the treated group and ended higher than with placebo.[8]
  • A second look at 80 of these patients, 43 treated and 37 on placebo, found less stomach lining swelling and lower inflammation scores on camera exams.[9]
  • In 48 people with acute pancreatitis, adding Thymogen to usual treatment was reported to correct a T cell shortfall and improve their course, compared with 36 healthy donors, not with a placebo group.[6]
  • In people with type 1 diabetes and signs of weak immunity, a 1996 Russian report said 94.4% had a clinical response and 83.3% a lab response, without giving patient numbers or a control group.[20] A 1999 report in destructive lung tuberculosis gave no numbers.[30]
  • A 1993 Russian report in an army training group said Thymogen given in the nose or under the skin cut the number, severity and length of colds and flu, but gives no numbers.[18]
  • A Russian study in older adults having abdominal cancer surgery reported better immune markers, fewer complications and faster recovery with a Thymogen nasal spray, but its summary gives no patient numbers.[19]
  • In Australia, a small safety study of oglufanide in chronic hepatitis C was stopped early, and a pilot study testing whether a nasal form lowers virus levels is listed as completed with no results posted.[31][27]

Limit: The controlled Western trials were in cancer and found no benefit. Proof for immune and stomach benefits rests on Russian studies from a small set of teams.

Claims check

The most common claims about this compound, and what studies actually found. Verdicts rate the evidence, not whether you should use it.

Boosts the immune system

Mixed results

Russian studies report better immune markers in 48 people with acute pancreatitis, in older adults having cancer surgery and in people with type 1 diabetes, but none used a placebo and some give no patient numbers.[6][19][20] A 2024 review says it helps restore white blood cells after chemotherapy.[1] Western trials of the same molecule did not test immune benefits.

Fights cancer

No benefit in trials so far

An early uncontrolled study of 44 people with Kaposi sarcoma looked promising.[17] But a placebo controlled trial of 202 people found no benefit and faster worsening on IM862, a trial of 71 men with prostate cancer found no benefit, and no tumors shrank in 25 people with kidney cancer.[2][3][7] A 2022 systematic review found too little evidence to recommend any Kaposi sarcoma treatment it covered, IM862 included.[21]

Heals the stomach lining

Mixed results

One Russian placebo controlled trial of 116 people with H. pylori gastritis found 26.1% more stomach glands after treatment and less inflammation in a group of 80.[8][9] This comes from one team and has not been repeated elsewhere.

Prevents colds and flu

Mixed results

A 1993 Russian report in an army training group said soldiers given Thymogen in the nose or under the skin had fewer, milder and shorter colds and flu, but it gives no numbers or description of the comparison group.[18] In mice with flu pneumonia, the nasal spray used before infection cut lung virus about 32 times by day 3.[10] In another mouse flu study, Thymogen alone helped less than a standard flu drug.[22]

Lowers inflammation

Mixed results

In immune cells in a dish, it cut several inflammation signals by up to 6 times.[23] Another dish study found it lowered IL1 alpha and IL8 from blood vessel and blood immune cells.[24] In people, the only support is lower stomach inflammation scores in one Russian trial.[9]

Slows aging

Only in animals

In 76 female rats, average lifespan was the same with or without the dipeptide, but the longest lived tenth of treated rats lived about 1,048 days versus 949 days for controls, and tumors were 1.5 times less common.[25] No study has measured aging in people.

Speeds skin and wound healing

Only in animals

In human skin cells in a dish, Glu-Trp boosted a cell renewal marker and lowered a cell death protein.[15] We did not find a controlled trial of skin or wound healing in people.

Known risks and side effects

  • Unregulated products. It is sold online outside pharmacies with no FDA review, so what is in the vial or capsule, how pure it is, and how much it holds are unknown.[32]
  • May worsen some cancers. In the largest trial, Kaposi sarcoma got worse faster with IM862 than with placebo, at 16 versus 35 weeks.[2]
  • Mild side effects in trials. Trials reported mild headache, tiredness, tingling and nausea, sinus irritation, and one flare of bowel disease among 25 kidney cancer patients. A trial of 71 men found no significant side effects.[17][7][3]
  • Not proven against infections. The antiviral support comes from mice and cells in a dish, and the only human report on colds gave no numbers, so it should not replace vaccines or proven antiviral care.[10][18]
  • Sport rules unclear. WADA does not name it in its 2026 or 2027 list. Its ban on unapproved drugs may not apply because it is registered in Russia, so athletes should check with their anti doping agency.[33][34][1]

Regulatory status

Today: Thymogen is registered as a medicine in Russia.[1] It is not approved by the FDA. Its US orphan drug status for AIDS related Kaposi sarcoma never led to approval.[35] It is not named on FDA's list of risky bulk substances for compounding as updated April 22, 2026, or on FDA's list of substances nominated for pharmacy compounding as updated May 14, 2026.[32][36] WADA does not name it on its 2026 list or on its 2027 list, which takes effect January 1, 2027.[33][34]

  1. FDA gave the molecule orphan drug status for AIDS related Kaposi sarcoma. It was never approved for that use.[35]
  2. A placebo controlled trial in 202 patients found IM862 was no better than placebo for Kaposi sarcoma.[2]
  3. A safety study of oglufanide in hepatitis C was registered in Australia. It was later stopped early.[31]
  4. A pilot study of nasal oglufanide in hepatitis C was registered in Australia. No results have been posted.[27]
  5. Date of the Russian registration certificate cited in a 2024 review.[1]

Sources

  1. Deigin V, Linkova N, Vinogradova J, Vinogradov D, Polyakova V, Medvedev D, Krasichkov A, Volpina O. The First Reciprocal Activities of Chiral Peptide Pharmaceuticals: Thymogen and Thymodepressin, as Examples. Int J Mol Sci. 2024;25(9):5042. PMID 38732260
  2. Noy A, Scadden DT, Lee J, Dezube BJ, Aboulafia D, Tulpule A, Walmsley S, Gill P. 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. J Clin Oncol. 2005;23(5):990-8. PMID 15598977
  3. Mao S, Daliani DD, Wang X, Thall PF, Do KA, Perez CA, Brown MA, Bouchillon K, Carter CM, Logothetis CJ, Kim J. Employing the treatment-free interval of intermittent androgen ablation to screen candidate prostate cancer therapies. Prostate. 2007;67(15):1677-85. PMID 17879948
  4. Morozov VG, Khavinson VK. Natural and synthetic thymic peptides as therapeutics for immune dysfunction. Int J Immunopharmacol. 1997;19(9-10):501-5. PMID 9637345
  5. Smith DL, Cai J, Zhu S, Wei W, Fukumoto J, Sharma S, Masood R, Gill PS. Natural killer cell cytolytic activity is necessary for in vivo antitumor activity of the dipeptide L-glutamyl-L-tryptophan. Int J Cancer. 2003;106(4):528-33. PMID 12845648
  6. Saidakhmedova ZT. [Immunomodulating activity of thymogen in acute pancreatitis]. Vopr Pitan. 2000;69(6):35-6. PMID 11452372
  7. Deplanque G, Madhusudan S, Jones PH, Wellmann S, Christodoulos K, Talbot DC, Ganesan TS, Blann A, Harris AL. Phase II trial of the antiangiogenic agent IM862 in metastatic renal cell carcinoma. Br J Cancer. 2004;91(9):1645-50. PMID 15354209
  8. Baryshnikova NV, Uspensky YP, Fominykh YA, Kalinina EY, Krylova YS, Krasnov AA, Petlenko SV, Apryatina VA. [Repair stimulator alpha-glutamyl-tryptophan in the complex therapy of chronic atrophic gastritis: results of histological examination]. Arkh Patol. 2023;85(3):54-63. PMID 37272441
  9. Baryshnikova NV, Uspenskiy YP, Fominykh YA, Petlenko SV, Zaplutanov VA, Apryatina VA, Krasnov AA. [Endoscopic and morphometric analysis of the reduction of acute inflammatory process in the gastric mucosa after therapy with Regasthym Gastro]. Ter Arkh. 2023;95(4):322-326. PMID 38158980
  10. Zarubaev VV, Garshinina AV, Esaulkova YaL, Mihalskij MG, Smirnov VS, Kudryavtseva TA, Petlenko SV, Zaplutanov VA. Study of the Protective Activity of Thymogen Dosed Nasal Spray on a Model of Experimental Influenza Pneumonia in Laboratory Animals. Antibiot Khimioter. 2023;68(9-10):46-57. DOI 10.37489/0235-2990-2023-68-9-10-46-57
  11. Smirnov VS, Zarubaev VV, Kudryavtseva TA, Esaulkova IL, Volobueva AS, Zaplutanov VA, Petlenko SV. Virucidal Activity of the Drug Thymogen, a Nasal Dosed Spray, Against Human Respiratory Viruses In Vitro. Antibiot Khimioter. 2025;70(3-4):5-11. DOI 10.37489/0235-2990-2025-70-3-4-5-11
  12. Leneva IA, Smirnov VS, Kudryavtseva TA, Fayzuloev EB, Gracheva AV, Kartashova NP, Zaplutanov VA, Petlenko SV. Local antiviral activity of the drug Thymogen, nasal dosed spray, against SARS-CoV-2 coronavirus in vitro. Antibiot Khimioter. 2021;66(5-6):11-16. DOI 10.37489/0235-2990-2021-66-5-6-11-16
  13. Filippova OV, Reznikov KM, Alabovskii VV, Khamburov VV, Vinokurov AA. [The effect of thymogen on the heart in ischemia and reperfusion]. Eksp Klin Farmakol. 1997;60(3):27-9. PMID 9324392
  14. Reznikov KM, Vinokurova OV, Alabovskii VV, Vinokurov AA. [The anti-arrhythmia properties of thymogen]. Eksp Klin Farmakol. 1994;57(6):31-3. PMID 7756955
  15. Malinin VV, Durnova AO, Polyakova VO, Kvetnoi IM. Dipeptides Increase Functional Activity of Human Skin Fibroblasts. Bull Exp Biol Med. 2015;159(1):164-7. PMID 26033609
  16. Bergeon JA, Chan YN, Charles BG, Toth I. Oral absorption enhancement of dipeptide L-Glu-L-Trp-OH by lipid and glycosyl conjugation. Biopolymers. 2008;90(5):633-43. PMID 18428206
  17. Tulpule A, Scadden DT, Espina BM, Cabriales S, Howard W, Shea K, Gill PS. Results of a randomized study of IM862 nasal solution in the treatment of AIDS-related Kaposi's sarcoma. J Clin Oncol. 2000;18(4):716-23. PMID 10673512
  18. Furgal SM, Degtiarev AA, Seryi SV, Khavinson VKh. [The clinico-epidemiological efficacy of thymogen in acute respiratory viral infections in a military collective]. Voen Med Zh. 1993;(2):31-2, 80. PMID 8498021
  19. Smirnov VS, Petlenko SV, El'tsin SS. [Application thymogen for preoperative preparation of elderly patients with tumor processes in abdominal cavity]. Adv Gerontol. 2011;24(2):278-84. PMID 21957588
  20. Zhuk EA, Galenok VA. [Thymogen in the treatment of type-1 diabetes mellitus]. Ter Arkh. 1996;68(10):12-4. PMID 9026934
  21. Liew YCC, Tam YCS, Oh CC. Treatments for AIDS/HIV-related Kaposi sarcoma: A systematic review of the literature. Int J Dermatol. 2022;61(11):1311-1324. PMID 35775738
  22. Smirnov VS, Zarubaev VV, Anfimov PM, Shtro AA. [Effect of a combination of glutamyl-tryptophan and glycyrrhizic acid on the course of acute infection caused by influenza (H3H2) virus in mice]. Vopr Virusol. 2012;57(3):23-7. PMID 22905423
  23. Linkova N, Khavinson V, Diatlova A, Petukhov M, Vladimirova E, Sukhareva M, Ilina A. The Influence of KE and EW Dipeptides in the Composition of the Thymalin Drug on Gene Expression and Protein Synthesis Involved in the Pathogenesis of COVID-19. Int J Mol Sci. 2023;24(17):13377. PMID 37686182
  24. Golovacheva EG, Starikova EA, Kudryavtseva TA, Apryatina VA. The Effect of Drugs with alpha-Glutamyl-Tryptophan for Cytokine Secretion and Level of Surface Molecule ICAM-1 In Vitro. Cell Tissue Biol. 2023;17(2):146-152. PMID 37131521
  25. Anisimov VN, Khavinson VK, Morozov VG. Immunomodulatory synthetic dipeptide L-Glu-L-Trp slows down aging and inhibits spontaneous carcinogenesis in rats. Biogerontology. 2000;1(1):55-9. PMID 11707921
  26. U.S. FDA Global Substance Registration System. Oglufanide (UNII 4RHY598T5U). FDA GSRS
  27. Australian New Zealand Clinical Trials Registry. A pilot phase II open-label study of oglufanide disodium in patients with chronic hepatitis C. ACTRN12607000418471. Registered August 17, 2007. ACTRN12607000418471
  28. Avolio F, Martinotti S, Khavinson VK, Esposito JE, Giambuzzi G, Marino A, Mironova E, Pulcini R, Robuffo I, Bologna G, Simeone P, Lanuti P, Guarnieri S, Trofimova S, Procopio AD, Toniato E. Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line. Int J Mol Sci. 2022;23(7):3607. PMID 35408963
  29. Bespalov VG, Troian DN, Petrov AS, Morozov VG, Khavinson VKh. [Inhibiting effect of thymogen on the development of tumors of the esophagus and forestomach induced by N-nitrososarcosine ethyl ester in rats]. Eksp Onkol. 1989;11(4):23-6. PMID 2759010
  30. Medus AI, Pisarevskaia LI, Nikishina EV. [The effect of thymogen on the state of immunity in destructive pulmonary tuberculosis]. Voen Med Zh. 1999;320(10):65-7, 96. PMID 10605346
  31. Australian New Zealand Clinical Trials Registry. A phase Ib dose escalation study of the safety and tolerability of oglufanide disodium (IM862) in patients with chronic hepatitis C virus (HCV) infection. ACTRN12606000505505. Registered December 6, 2006. ACTRN12606000505505
  32. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. Content current as of April 22, 2026. FDA
  33. World Anti-Doping Agency. The 2026 Prohibited List, World Anti-Doping Code International Standard. In force January 1, 2026. WADA 2026
  34. World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2027. In force January 1, 2027. WADA 2027
  35. U.S. Food and Drug Administration, Office of Orphan Products Development. Orphan drug designation: L-glutamyl-L-tryptophan, treatment of AIDS-related Kaposi's sarcoma. Designated October 20, 1999. FDA orphan designation
  36. U.S. Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act. Updated May 14, 2026. FDA 503A list
Medical disclaimer

This page is educational information only. It is not medical advice and does not replace care from a licensed medical provider. Do not use this page to decide whether to take any substance. Talk to a licensed medical provider first.

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