Khavinson Short Peptides: Vilon, Vesugen, Testagen, and Prostamax Explained

Research-use-only context. This article summarizes published third-party scientific literature and laboratory practice. It is not medical advice, not a therapeutic or performance claim, and not a usage guide. US Prime Peptides products are supplied strictly for in vitro laboratory research and are not for human or veterinary use.

This article explains what Vilon, Vesugen, Testagen, and Prostamax are, where their sequences came from, what the "peptide bioregulator" hypothesis behind them claims, and what the published studies actually measured. It is candid about the evidence: nearly all of it comes from one research group, much of it was first published in Russian, and almost none of it has been independently replicated.

Four very short peptides built from the same three residues

Vilon, Vesugen, Testagen, and Prostamax are trade names for a dipeptide, a tripeptide, and two tetrapeptides that share a lysine-glutamate core. Vilon is Lys-Glu (KE). Vesugen is Lys-Glu-Asp (KED). Testagen is Lys-Glu-Asp-Gly (KEDG). Prostamax is Lys-Glu-Asp-Pro (KEDP). All four were designed in the laboratory of V. Kh. Khavinson at the St. Petersburg Institute of Bioregulation and Gerontology, and all four belong to a larger family that also includes Epithalon (Ala-Glu-Asp-Gly) and Pinealon (Glu-Asp-Arg), which have their own articles: the Epithalon overview and the Pinealon overview.

Two things stand out from the table. First, these are among the smallest molecules sold as research peptides; Vilon at 275 daltons is lighter than many small-molecule drugs. Second, none of the four contains an aromatic residue, which has a direct analytical consequence discussed below. The Testagen row also shows a naming inconsistency worth knowing: the 2011 and 2013 papers by Kuznik and colleagues describe Lys-Glu-Asp-Gly as a peptide designed from the amino acid composition of anterior pituitary extracts, while vendors and later reviews associate it with the testis. The sequence is the same; the organ story is not consistent across sources.

The bioregulator hypothesis and how the sequences were chosen

Khavinson's 2002 monograph "Peptides and Ageing" in Neuroendocrinology Letters lays out the method. The group first prepared crude peptide extracts from organs (thymus, pineal gland, prostate, vessels), observed in organotypic culture that an extract tended to stimulate outgrowth of explants from the same organ, and then designed short synthetic peptides "based on the data about the amino acid compositions" of those extracts. The short peptides were selected because they reproduced the organ-selective effect on explants in culture. That is the origin of the "bioregulator" label: a short peptide proposed to carry a tissue-specific signal.

The proposed mechanism is that these peptides enter cells, reach the nucleus, and bind DNA or histones to change gene expression. Fedoreyeva, Kireev, Khavinson, and Vanyushin reported in a 2011 Biochemistry (Moscow) paper that fluorescein-labeled Epithalon, Pinealon, and Testagen produced fluorescence in the cytoplasm, nucleus, and nucleolus of HeLa cells, and that the peptides quenched the fluorescence of labeled oligonucleotides in a sequence-dependent way, with apparent preferences for CAG-containing sequences. A 2013 follow-up found binding to labeled wheat histones. Khavinson's 2016 Bulletin of Experimental Biology and Medicine paper built docking models for 19 short peptides and proposed that KE and EDP bind an AGAT motif. A 2023 Biomolecules paper from the same group used docking to argue that KED, KEDG, KEDP, and others fit the binding sites of the LAT1, LAT2, and PEPT1 transporters, offering a route into cells.

It should be clear what kind of evidence this is. The HeLa uptake and oligonucleotide quenching are in vitro biophysics; the DNA, histone, and transporter binding are mostly computational. A systematic docking study by Kolchina, Khavinson, and colleagues in Nucleic Acids Research in 2019 is the most rigorous entry and is also the most sobering: screening all 400 dipeptides against all tetranucleotide centers in B-form DNA, they found that "the vast majority of the dipeptides were found to be unable to bind dsDNA", with only 57 low-energy complexes identified. Whether KE is among the binders in a living nucleus has not been shown experimentally.

Vilon (Lys-Glu): the most-studied of the four

Vilon has the largest literature. Khavinson and Anisimov reported in a 2000 Doklady Biological Sciences paper, and in a companion 2000 paper in the Bulletin of Experimental Biology and Medicine, that female CBA mice given the dipeptide from six months of age showed higher physical activity, lower body temperature, longer lifespan, and fewer spontaneous tumors than controls, with no effect on estrous cycling or free-radical markers. Anisimov, Bokheler, and Khavinson's 2002 microarray study measured expression of 15,247 cDNA clones in mouse heart and reported that Vilon changed 36 clones more than two-fold, Epithalon 98, and the combination 144.

The cell-culture work is of two kinds. Lezhava, Khavinson, and colleagues reported in a 2004 Biogerontology paper that Vilon added to cultured lymphocytes from old people decondensed facultative heterochromatin and reactivated nucleolar organizer regions, without affecting pericentromeric constitutive heterochromatin. Sevostianova and colleagues' 2013 paper exposed cultured human and rat thymic cells to two dipeptides and measured a rise in the CD5 differentiation marker and shifts toward CD4-positive and CD8-positive phenotypes. Khavinson, Tarnovskaya, and colleagues' 2015 paper is a useful control experiment: in organotypic spleen culture, Lys-Glu stimulated proliferation while an equimolar mixture of free lysine and glutamic acid inhibited it, which argues that the peptide bond matters and that the effect is not simply amino acid supplementation.

A fair summary: the mouse lifespan and tumor data come from a single laboratory and have not been repeated elsewhere; the chromatin, marker, and microarray findings are descriptive; and no study has yet linked a specific gene change to a specific DNA-binding event for KE.

Vesugen, Testagen, and Prostamax: thinner literatures

Vesugen (KED) appears in Chalisova and colleagues' 2012 Bulletin of Experimental Biology and Medicine paper, which exposed organotypic cultures of rat pineal, thymus, and spleen tissue to the tripeptide and reported lower p53 and higher Ki-67 staining in pineal cultures (more so in cultures from old animals) and induction of the CD5 and CD68 markers in immune-cell cultures. Khavinson, Linkova, and Polyakova's 2012 paper found that KED increased expression of the differentiation factors CXCL12 and WEGC1 in late-passage human prostatic fibroblast cultures, the effect being larger in "aged" cultures. The vascular association in the name rests on organ-extract work and on the group's reviews rather than on an endothelial study indexed in PubMed under the peptide's name.

Testagen (KEDG) has the oddest literature. Kuznik, Pateyuk, and Rusaeva published a series between 2008 and 2013 in which neonatally hypophysectomized chickens and old hens received KEDG or AEDG; the papers report partial recovery of thyroid hormone levels and of thymus and thyroid histology, with KEDG the more active of the two. These are bird studies with pituitary removal as the model, which is a long way from any mammalian testis question. Separately, Fedoreyeva's 2011 HeLa work included Testagen among the nucleus-penetrating peptides. The most recent indexed paper, Dobriţescu and colleagues' 2025 study in Molecules, has nothing to do with biology: it reports that KEDG adsorbs on copper surfaces in saline and inhibits corrosion by about 86%, with a Freundlich isotherm and DFT modeling. It is a reminder that a tetrapeptide is also just a small chelating molecule.

Prostamax (KEDP) has the least. Dzhokhadze and colleagues' 2012 paper in Georgian Medical News reported that the tetrapeptide added to cultured lymphocytes from people aged 75 to 86 roughly doubled sister chromatid exchange frequency and increased silver-stained nucleolar organizer regions, interpreted as chromatin decondensation. Solovyev and colleagues' 2015 paper in the International Journal of Biological Macromolecules measured DNA melting temperature and found that KE, AEDG, and KEDP each shifted it, with acidic residues weakening and basic residues strengthening strand pairing. A prostate-cell study of KEDP indexed under its own name was not located.

Evidence quality and regulatory status

The limitations apply to all four peptides and should be weighed before any of them is chosen for a research program. The primary papers come overwhelmingly from the St. Petersburg Institute of Bioregulation and Gerontology and its collaborators in Chita, Tbilisi, and Moscow. The main venues are the Bulletin of Experimental Biology and Medicine (the English translation of a Russian journal) and Advances in Gerontology, where abstracts are often the only English text. Group sizes are small, blinding is rarely described, and the same senior authors appear on the review articles that summarize the work, including the 2020 Stem Cell Reviews and Reports review that assigns each peptide a differentiation role. The 2022 THP-1 paper by Avolio and colleagues in an international journal refers to the materials as "Khavinson Peptides®", which signals a commercial interest that readers should factor in. No independent laboratory outside this network has published a replication of the lifespan, tumor, or chromatin findings.

None of the four is an approved drug in the United States, and none has a marketing application on record. A research vial is supplied for in vitro laboratory work only. The FDA status reference table tracks the regulatory position of these and other Khavinson peptides, including the warning-letter activity it notes for Prostamax.

Certificate notes for di-, tri-, and tetrapeptides

Very short peptides are easy to confirm by mass spectrometry, because the calculated mass is small and unambiguous: about 275.3 daltons for KE, 390.4 for KED, 447.4 for KEDG, and 487.5 for KEDP. The challenge is purity. None of the four contains tryptophan, tyrosine, or phenylalanine, so none absorbs at 280 nm; HPLC purity must be measured at 210 to 220 nm, where the peptide bond absorbs, and the certificate should state the wavelength. Short, highly polar peptides also elute early on reversed-phase columns, close to the solvent front, so a chromatogram showing a well-retained main peak is worth checking against the method description. Net peptide content by amino acid analysis matters because small, charged peptides carry a large proportion of counter-ion and water by mass; the net peptide content article explains why a 99% area-percent purity can still correspond to a much lower peptide mass. These peptides are also hygroscopic, which affects weighing and storage.

US Prime Peptides posts a lot-matched certificate with mass spectrometry identity, HPLC purity, net content, endotoxin, sterility, and heavy metals for Vilon 20 mg, Vesugen 20 mg, Testagen 20 mg, and Prostamax 20 mg on each product page before purchase.

Frequently Asked Questions

What is the difference between Vilon, Vesugen, Testagen, and Prostamax?

They are four short synthetic peptides from the Khavinson laboratory that share a Lys-Glu core: Vilon is Lys-Glu, Vesugen is Lys-Glu-Asp, Testagen is Lys-Glu-Asp-Gly, and Prostamax is Lys-Glu-Asp-Pro. Each was designed from the amino acid composition of a different organ extract and is associated by the group with that organ.

Are Khavinson peptides backed by independent research?

Largely not. Nearly all primary studies come from the St. Petersburg Institute of Bioregulation and Gerontology and its collaborators, many first published in Russian, with small group sizes. The strongest independent-style entry, a 2019 docking study in Nucleic Acids Research, still lists Khavinson as a coauthor and found that most dipeptides do not bind double-stranded DNA.

How do bioregulator peptides supposedly work?

The group proposes that the peptides enter the nucleus and bind DNA or histones to change gene expression. Supporting data are fluorescence uptake in HeLa cells, oligonucleotide and histone quenching assays, DNA melting-temperature shifts, and computational docking. A direct demonstration that a specific peptide-DNA contact changes a specific gene in a living cell has not been published.

Are Vilon, Vesugen, Testagen, or Prostamax approved drugs?

No. None of the four is an approved drug in the United States, and none has a marketing application on record. Research-grade vials are supplied for in vitro laboratory use only.

Citations

1. Khavinson VKh. Peptides and ageing. Neuro Endocrinol Lett. 2002;23 Suppl 3:11-144. PMID 12374906
2. Khavinson VKh, Anisimov VN. A synthetic dipeptide vilon (L-Lys-L-Glu) inhibits growth of spontaneous tumors and increases life span of mice. Dokl Biol Sci. 2000;372:261-263. PMID 10944717
3. Khavinson VK, Anisimov VN, Zavarzina NY, et al. Effect of vilon on biological age and lifespan in mice. Bull Exp Biol Med. 2000;130:687-690. PMID 11140587
4. Anisimov SV, Bokheler KR, Khavinson VKh, Anisimov VN. Studies of the effects of Vilon and Epithalon on gene expression in mouse heart using DNA-microarray technology. Bull Exp Biol Med. 2002;133:293-299. PMID 12360356
5. Lezhava T, Khavison V, Monaselidze J, et al. Bioregulator Vilon-induced reactivation of chromatin in cultured lymphocytes from old people. Biogerontology. 2004;5:73-79. PMID 15105581
6. Sevostianova NN, Linkova NS, Polyakova VO, et al. Immunomodulating effects of Vilon and its analogue in the culture of human and animal thymus cells. Bull Exp Biol Med. 2013;154:562-565. PMID 23486604
7. Khavinson VKh, Tarnovskaya SI, Lin'kova NS, et al. Role of peptide bond in the realization of biological activity of short peptides. Bull Exp Biol Med. 2015;158:551-554. PMID 25705040
8. Chalisova NI, Lopatina NG, Kamishev NG, et al. Effect of tripeptide Lys-Glu-Asp on physiological activity of neuroimmunoendocrine system cells. Bull Exp Biol Med. 2012;153:569-572. PMID 22977872
9. Khavinson VKh, Linkova NS, Polyakova VO, et al. Peptides tissue-specifically stimulate cell differentiation during their aging. Bull Exp Biol Med. 2012;153:148-151. PMID 22808515
10. Kuznik BI, Pateyuk AV, Rusaeva NS, et al. Effects of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on hormonal activity and structure of the thyroid gland in hypophysectomized young chickens and old hens. Bull Exp Biol Med. 2011;150:495-499. PMID 22268052
11. Pateyk AV, Baranchugova LM, Rusaeva NS, et al. Effect of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the morphology of the thymus in hypophysectomized young and old birds. Bull Exp Biol Med. 2013;154:681-685. PMID 23658898
12. Dzhokhadze TA, Buadze TZh, Gaiozishvili MN, et al. [Deheterochromatinization of the chromatin in old age induced by oligopeptide bioregulator (Lys-Glu-Asp-Pro)]. Georgian Med News. 2012;(213):76-82. PMID 23221144
13. Fedoreyeva LI, Kireev II, Khavinson VKh, Vanyushin BF. Penetration of short fluorescence-labeled peptides into the nucleus in HeLa cells and in vitro specific interaction of the peptides with deoxyribooligonucleotides and DNA. Biochemistry (Mosc). 2011;76:1210-1219. PMID 22117547
14. Fedoreyeva LI, Smirnova TA, Kolomijtseva GY, et al. Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides. Biochemistry (Mosc). 2013;78:166-175. PMID 23581987
15. Solovyev AY, Tarnovskaya SI, Chernova IA, et al. The interaction of amino acids, peptides, and proteins with DNA. Int J Biol Macromol. 2015;78:39-45. PMID 25841380
16. Khavinson VK, Lin'kova NS, Tarnovskaya SI. Short peptides regulate gene expression. Bull Exp Biol Med. 2016;162:288-292. PMID 27909961
17. Kolchina N, Khavinson V, Linkova N, et al. Systematic search for structural motifs of peptide binding to double-stranded DNA. Nucleic Acids Res. 2019;47:10553-10563. PMID 31598715
18. Khavinson V, Linkova N, Diatlova A, Trofimova S. Peptide regulation of cell differentiation. Stem Cell Rev Rep. 2020;16:118-125. PMID 31808038
19. Khavinson VK, Linkova NS, Rudskoy AI, Petukhov MG. Feasibility of transport of 26 biologically active ultrashort peptides via LAT and PEPT family transporters. Biomolecules. 2023;13:552. PMID 36979488
20. Avolio F, Martinotti S, Khavinson VK, et al. Peptides regulating proliferative activity and inflammatory pathways in the monocyte/macrophage THP-1 cell line. Int J Mol Sci. 2022;23:3607. PMID 35408963
21. Dobriţescu A, Samide A, Cioateră N, et al. The inhibitory effect and adsorption properties of testagen peptide on copper surfaces in saline environments: an experimental and computational study. Molecules. 2025;30. PMID 40807317

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