Vilon
Summary
Vilon is the Khavinson dipeptide Lys-Glu (KE), an active substance of the calf thymus complex Thymalin. In vitro it promotes T-cell differentiation markers and reduces LPS-induced inflammatory cytokines; a lifelong mouse study raised physical activity and reduced lung adenomas without extending survival. No human trial or pharmacokinetic study exists.
Also known as: KE, Lys-Glu, AB-O peptide, Lysylglutamic acid
Key Findings at a Glance
- • Vilon (Lys-Glu, KE) is the shortest Khavinson thymic bioregulator and one of the defined active substances of the registered Russian drug Thymalin.
- • Isolated KE reduced TNF-α, IL-1β, and IL-6 synthesis in inflamed human blood cells, outperforming the whole Thymalin complex at the TNF-α endpoint in the same assay.
- • Lifelong monthly KE dosing in CBA mice increased physical activity and reduced spontaneous lung adenomas but did not significantly extend survival.
- • Docking work from the developing group proposes KE binds GCGC motifs in nucleosomal DNA, the epigenetic mechanism claimed for the class; no receptor has been identified.
Vilon Overview & Molecular Profile
Vilon is a synthetic dipeptide with the sequence Lys-Glu (abbreviated KE), developed at the St. Petersburg Institute of Bioregulation and Gerontology as a defined active constituent of Thymalin, a calf thymus polypeptide complex registered as an immunomodulatory drug in Russia. In the Thymalin literature KE sits alongside the EW dipeptide (Glu-Trp, known as Thymogen), and 2023 mechanistic work from that network reported that KE preferentially docks to GCGC motifs in nucleosomal DNA. Experimental findings include increased expression of T-cell differentiation markers in cultured thymic cells, reduced IL-1β, IL-6, and TNF-α synthesis in LPS-stimulated human blood cells, and selective decondensation of chromatin in lymphocytes from elderly donors. Vilon belongs to the same broad thymic peptide class as Thymosin Alpha-1, though their evidence bases differ enormously: nearly all Vilon data comes from one institutional network, and no randomized trial or pharmacokinetic study has been published.
Mechanism of Action: Gene Expression & Epigenetic Regulation
The proposed mechanism is epigenetic rather than receptor-mediated: molecular docking from the developing group indicates KE preferentially binds GCGC sequence motifs in curved nucleosomal DNA, a proposed route to transcriptional modulation of cytokine genes, with the CHUK gene identified as a specific potential target. In lipopolysaccharide-stimulated human peripheral blood mononuclear cells, KE reduced synthesis of the inflammatory cytokines IL-1β, IL-6, and TNF-α. In cultured human and rat thymic cells, KE (reported under the code AB-O) increased expression of the lymphocyte differentiation marker CD5 and promoted maturation of T-cell precursors toward CD4+ helper cells. No cell-surface receptor has been identified, and the mechanism has not been characterized outside the originating research network.
Vilon Pharmacokinetics: No Published Measurements for the KE Dipeptide
No pharmacokinetic study of isolated Vilon (Lys-Glu) has been published in any species. As an unmodified dipeptide it is expected to be degraded rapidly by plasma and tissue peptidases; any half-life figure in secondary sources is class-level extrapolation, not measurement.
Class-Level Inference Only
- • Linear dipeptides are substrates for aminopeptidases and typically clear from plasma within minutes; no KE-specific plasma measurement exists, the same data gap documented for epithalon in a 2025 systematic review (PMID 40141333).
- • The 2023 transporter docking analysis from the developing network proposed LAT and PEPT family transporters as a cellular uptake route for ultrashort peptides of this class; this is computational inference, not measured transport (PMID 36979488).
Why Effects May Outlast Plasma Presence
- • In the LPS-stimulated blood cell assay, KE altered cytokine synthesis through a proposed DNA-level interaction, a mechanism in which brief exposure can trigger a sustained transcriptional response (PMID 37686182).
- • The lifelong CBA mouse study dosed only five consecutive days per month yet reported persistent behavioral and tumor-incidence differences, consistent with a trigger model rather than continuous exposure (PMID 11163623).
Research-Observed Effects
T-Cell Differentiation
Moderate ResearchIn cultured human and rat thymic cells, Vilon (reported as dipeptide AB-O) increased expression of the lymphocyte differentiation marker CD5 and drove T-cell precursor differentiation toward CD4+ helper cells. Related work from the same network showed the parent complex Thymalin increased the mature T-lymphocyte marker CD28 by 6.8-fold in cultured human hematopoietic stem cells while reducing stem and intermediate markers CD44 and CD117. These are in vitro findings from a single research network; no human T-cell outcome study of isolated KE exists.
Inflammatory Cytokine Reduction
Moderate ResearchIn LPS-stimulated human peripheral blood mononuclear cells, KE reduced synthesis of IL-1β, IL-6, and TNF-α, with reductions across cytokines and peptides reported in the 1.4- to 6-fold range in the 2023 IJMS study; isolated KE outperformed the whole Thymalin complex at the TNF-α endpoint in that assay. A 2022 Italian-Russian collaboration reported reduced TNF and IL-6 production and reduced monocyte adhesion to activated endothelium in THP-1 macrophage cultures, adding partial non-Russian co-authorship to an otherwise single-network literature.
Chromatin Decondensation in Aged Cells
Preliminary ResearchIn ex vivo lymphocyte cultures from donors aged 75-88, KE induced selective decondensation of heterochromatin and reactivation of ribosomal genes, with chromosome-region selectivity differing between the short peptides tested. The Georgian group performing this work frames it as reversal of age-related heterochromatinization; the finding is ex vivo, from a single collaborating group, and involves no functional human endpoints.
Geroprotection in Animal Models
Preliminary ResearchIn female CBA mice dosed lifelong with KE (0.1 mcg per animal, five consecutive days monthly from 6 months of age), treatment increased physical activity and reduced spontaneous lung adenoma incidence, but did not significantly extend survival; in the same experiment the pineal tetrapeptide Ala-Glu-Asp-Gly (epithalon) did extend mean survival by 5.3%. This makes the mouse record for KE genuinely mixed: functional and tumor-incidence benefits without a lifespan effect.
Safety & Tolerability
No human safety or pharmacokinetic study exists for isolated Vilon (KE). Human-relevant evidence is limited to in vitro donor-cell experiments, and the one long-term animal study reported good tolerance with lifelong monthly dosing in mice. Because KE promotes T-cell differentiation, its mechanism is directionally opposite to therapeutic immunosuppression, a theoretical concern for transplant and autoimmune contexts that has never been studied clinically.
Human data: No published human trials of any kind for isolated KE; all human-relevant data are in vitro (donor blood cells, THP-1 macrophages, ex vivo lymphocyte cultures). Human exposure occurs only through the parent complex Thymalin, whose evidence does not isolate KE.
Regulatory status: Isolated KE is not a registered drug anywhere; in Russia it is sold as a dietary supplement (BAFS). The parent complex Thymalin is a registered medicinal product in Russia.
- PubMed 11163623
Lifelong monthly KE administration in female CBA mice (0.1 mcg per animal, five consecutive days monthly from 6 months until natural death) produced no reported toxicity, increased physical activity, and reduced spontaneous lung adenomas, without significantly extending survival.
Animal - PubMed 37686182
In LPS-stimulated human donor blood cells KE reduced inflammatory cytokine synthesis; in vitro suppression of TNF-α does not establish human safety, and T-cell-promoting activity is theoretically unfavorable in transplant immunosuppression or active autoimmune disease.
In-vitro - PubMed 23486604
KE promoted T-cell precursor differentiation (CD5, CD4+) in human and rat thymic cell cultures, the same pro-T-cell mechanism that underlies both its claimed benefit and its theoretical risk in immunosuppressed or autoimmune contexts.
In-vitro
Research Protocol Doses Reported in Published Literature
Research Disclaimer: Doses reported below are from published preclinical research protocols. Vilon is not approved by the US FDA for human use; regulatory status can differ in other countries, so see the regulatory status note in the safety section of this page. This information is provided for research reference only and does not constitute a dosing recommendation.
| Route | Dose | Frequency | Notes |
|---|---|---|---|
| Subcutaneous (mouse) | 0.1 mcg/animal | 5 consecutive days monthly, lifelong | CBA mouse lifespan study (PMID 11163623); no human dosing established |
All doses above are reported from published research protocols using laboratory subjects. Refer to the cited studies in the Research Studies section above for original source data.
Research Studies & References
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
Linkova N, Khavinson V, Diatlova A, Petukhov M, et al.
International Journal of Molecular Sciences (2023)
This mechanistic study from the St. Petersburg network examined the KE and EW dipeptides, the active substances of Thymalin, in the context of COVID-19-related inflammation. Molecular docking found KE preferentially binds GCGC motifs in nucleosomal DNA, with the CHUK gene identified as a specific potential target. In LPS-stimulated human peripheral blood mononuclear cells, KE and EW reduced synthesis of IL-1β, IL-6, and TNF-α by 1.4- to 6-fold depending on cytokine and peptide; isolated KE was more potent at the TNF-α endpoint than the whole Thymalin complex in the same assay.
Immunomodulating effects of Vilon and its analogue in the culture of human and animal thymus cells
Sevostianova NN, Linkova NS, Polyakova VO, et al.
Bulletin of Experimental Biology and Medicine (2013)
This study examined two dipeptides, AB-O (Lys-Glu, i.e. Vilon) and R-1, in cultured human and rat thymic cells. Both increased expression of the lymphocyte differentiation marker CD5; AB-O induced T-cell precursor differentiation toward CD4+ T-helpers, though the authors report its effect as weaker than that of R-1, which additionally stimulated maturation toward CD8+ cytotoxic T cells. It is the primary cell-biology paper underlying Vilon's reputation as a thymic immunomodulator.
Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line
Avolio F, Martinotti S, Khavinson VK, et al.
International Journal of Molecular Sciences (2022)
A joint Italian-Russian study of Thymalin and its constituent peptides in the human THP-1 monocyte/macrophage line. KE and related peptides reduced TNF and IL-6 production in LPS-stimulated macrophages and reduced monocyte adhesion to activated endothelium. It is notable as partial non-Russian co-authorship in a literature otherwise confined to one institutional network, though the experiments remain in vitro.
Epigenetic modification under the influence of peptide bioregulators on the old chromatin
Lezhava T, Jokhadze T, Monaselidze J, et al.
Georgian Medical News (2023)
This Tbilisi State University study tested KE alongside epithalon, livagen, and cortagen in ex vivo lymphocyte cultures from donors aged 75-88. All four peptides induced selective decondensation of age-condensed heterochromatin and reactivated ribosomal gene activity at satellite stalks of acrocentric chromosomes, with each peptide showing chromosome-region selectivity. The work supports the epigenetic framing of Khavinson peptides but involves no in vivo or functional human endpoints.
Effect of synthetic thymic and pineal peptides on biomarkers of ageing, survival and spontaneous tumour incidence in female CBA mice
Anisimov VN, Khavinson VK, Mikhalski AI, Yashin AI
Mechanisms of Ageing and Development (2001)
Fifty female CBA mice received saline, Lys-Glu, or Ala-Glu-Asp-Gly subcutaneously (0.1 mcg per animal, five consecutive days monthly from 6 months until natural death). Lys-Glu did not significantly alter body weight, food consumption, free radical processes, or estrous function, but increased physical activity and reduced spontaneous lung adenoma incidence; survival was not significantly extended. In the same experiment the pineal tetrapeptide extended mean survival by 5.3%, making this study both the strongest animal geroprotection evidence for KE and an important honest negative on lifespan.
Thymalin: Activation of Differentiation of Human Hematopoietic Stem Cells
Khavinson VK, Linkova NS, Kvetnoy IM, et al.
Bulletin of Experimental Biology and Medicine (2020)
This study of the parent complex Thymalin (which contains KE) found it reduced stem-cell markers CD44 and CD117 by 2- to 3-fold and increased the mature T-lymphocyte marker CD28 by 6.8-fold in cultured human hematopoietic stem cells, interpreted as stimulated differentiation toward mature T cells. Because the tested material was the whole Thymalin complex rather than isolated KE, it supports Vilon's mechanism indirectly.
Frequently Asked Questions
What is Vilon?
Vilon is the synthetic dipeptide Lys-Glu (KE), developed at the St. Petersburg Institute of Bioregulation and Gerontology as a defined active substance of Thymalin, the calf thymus polypeptide complex. It is the shortest compound in the Khavinson thymic bioregulator family and is studied for T-cell differentiation, cytokine modulation, and epigenetic effects on chromatin in aged cells.
Is Vilon the same as Thymalin?
No. Thymalin is a polypeptide extract of calf thymus registered as a drug in Russia; Vilon is one of its defined synthetic constituents, the KE dipeptide. A 2023 IJMS study compared them directly in LPS-stimulated human blood cells: isolated KE reduced TNF-α synthesis more strongly than the whole Thymalin complex in that assay. Most clinical precedent attaches to Thymalin, not to isolated Vilon, for which no human trial exists.
What does Vilon do to the immune system?
In cell culture, KE increased the lymphocyte differentiation marker CD5 and pushed T-cell precursors toward CD4+ helper cells, and the parent complex Thymalin increased the mature T-cell marker CD28 by 6.8-fold in human hematopoietic stem cell cultures. In inflamed human blood cells and THP-1 macrophages, KE reduced IL-1β, IL-6, and TNF-α synthesis. The combined picture is pro-differentiation for T cells plus anti-inflammatory for cytokine output, but all of it is in vitro.
Does Vilon extend lifespan?
The one long-term animal study says no for survival: female CBA mice treated lifelong with KE showed increased physical activity and fewer spontaneous lung adenomas, but no significant survival extension, while the pineal peptide epithalon in the same experiment did extend mean survival by 5.3%. Human longevity claims for Vilon come from uncontrolled Khavinson-network reports and should be treated as unverified.
Is Vilon safe?
Human safety is uncharacterized: no Phase I trial, no pharmacokinetic study, and no controlled human exposure data exist for isolated KE. The mouse lifespan study reported no toxicity with lifelong monthly dosing. Because KE promotes T-cell activity, transplant recipients on immunosuppression and people with active autoimmune disease are theoretical risk groups that have never been studied. Outside Russia it is sold as a research chemical without pharmaceutical oversight.
Related Peptides
View allThymalin
Thymalin is a polypeptide complex isolated from calf thymus, developed in the Khavinson bioregulator program and registered as an immunomodulatory drug in Russia. It is studied for T-cell restoration, cytokine modulation, and geroprotection.
Thymosin Alpha-1
Thymosin Alpha-1 is a peptide originally isolated from thymic tissue that modulates immune function. It is approved in several countries for immune deficiency conditions and as an adjuvant therapy.
Thymulin
Thymulin is a zinc-dependent nonapeptide hormone produced by thymic epithelial cells that plays a central role in T-cell differentiation, immune regulation, and the neuroendocrine-immune axis.
Epithalon
Epithalon is a synthetic tetrapeptide based on the natural peptide Epithalamin produced by the pineal gland. It has been studied for effects on telomerase activity and longevity.
Vesugen
Vesugen is a synthetic tripeptide (Lys-Glu-Asp, KED) of the Khavinson bioregulator class, studied as a vascular endothelial regulator with mostly in vitro and animal evidence.
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