Vilon is two amino acids, lysine and glutamic acid, joined by one peptide bond. Lys-Glu, or KE. It is the smallest peptide on this site, with a mass of 275.3 and a formula of C11H21N3O5, and it is sold as a 20 mg vial that at first sight looks like any other. It is not like any other, and the reasons are worth a page: what a dipeptide is as a chemical object, what its certificate can and cannot establish, and why its literature should be read with the same care as any of the Khavinson short peptides.
What is Lys-Glu as a molecule?
A lysine with its free alpha-amine and its side-chain amine, joined to a glutamic acid with its free alpha-carboxyl and side-chain carboxyl. Two positive charges and two negative charges at neutral pH. It is about as polar as a molecule of its size can be, which makes it completely water-soluble and almost impossible to retain on a reversed-phase HPLC column, a point that matters for how its purity is measured and is covered below.
Lys-Glu is not a fragment of a particular protein in any meaningful sense; the dipeptide occurs in thousands of protein sequences. It was chosen by the Khavinson group as a synthetic representative of their thymic polypeptide extract, by the same compositional design logic that produced pinealon from a pineal extract. The group's own name for the thymic extract is Thymalin, and the relationship between that extract and the catalogue product that carries its name is the subject of the thymalin versus thymulin post.
What does the certificate for lot VILON20-0528 report?
COA4861, issued by Bioviridian Inc. on 17 June 2026, covers the lot in every vial currently on sale. It carries six tests, which is more than most lots on the site.
| Test | Method | Result |
|---|---|---|
| Identity | MALDI-MS | 275.3 observed |
| Purity | RP-HPLC, 214 nm | 99.9% |
| Content | Gravimetric against label | 20.13 mg |
| Endotoxin | LAL | < 0.05 EU/mL |
| Heavy metals | ICP | < 0.01 ppm |
| Sterility | Culture | Not detected |
The identity figure is exact for the formula: lysine 146.19 plus glutamic acid 147.13 minus the water lost in the peptide bond, 18.02, gives 275.30. MALDI-MS reports the molecular ion; for a dipeptide there is essentially nothing else with that mass that a synthesis of Lys-Glu would yield.
The sterility line is worth noticing. Sterility, endotoxin and pyrogenicity are three different questions, as the sterility post sets out, and most research-reagent certificates answer only the endotoxin one. This lot answers all three. For cell-culture work that is the line that removes the need for a filtration step, provided the vial is handled aseptically after opening.
Why is purity harder to measure for a dipeptide?
Because reversed-phase HPLC separates by hydrophobicity, and Lys-Glu has almost none. The certificate's retention time for this lot is 1.56 minutes, which on a typical gradient means the molecule came off the column close to the solvent front. Impurities that are also very polar, including the free amino acids, would elute in the same region. A 99.9% area figure for a dipeptide is therefore reassuring but less discriminating than the same number for a 2,000-dalton peptide that retains well and separates cleanly from its deletion sequences.
That is not a criticism of the certificate. It is a property of the molecule, and it is why the identity test by mass is doing more of the work here than it does for a longer peptide. The HPLC chromatogram post explains retention and why early-eluting peaks are harder to resolve.
How many micromoles are in 20 mg?
20.13 mg at 275.3 g/mol is 73.1 micromoles; the label's 20 mg is 72.6. Nothing else in the catalogue comes close, because nothing else is this small. Dissolved in 1 mL it is a 72.6 millimolar stock. An experiment that uses vilon at 10 micromolar in 100 wells of 200 microlitres consumes 0.2 micromoles, which is 0.3% of the vial.
That arithmetic is the honest answer to a question buyers ask: why is a dipeptide sold at the same vial size and a similar price to a tripeptide and a tetrapeptide? Because the cost of a short peptide is in synthesis, purification, testing and filling, not in the mass of amino acids, and because the molar amount is already far beyond what one study will use. The vial-size post covers how to compare vials on molar rather than milligram terms.
What does the literature report?
The thymic peptide work from the Khavinson programme, summarised in Anisimov and Khavinson's 2010 Biogerontology review, places Lys-Glu among the short synthetic peptides derived from the thymus extract and reports effects on cultured lymphoid cells and on immune measures in aged animals. The group proposes that these peptides act on gene expression directly.
What is absent is the same as for the rest of the series: an identified receptor, independent replication at scale, and any registered clinical trial. A search of ClinicalTrials.gov on 2 October 2026 found none for vilon. The bioregulator evidence post is the longer treatment of how to design a study on a compound with that profile.
The comparison that is most often drawn is with thymosin alpha-1, a 28-residue acetylated peptide with a very different and far larger literature. They are not alternatives to each other; the thymosin alpha-1 versus thymalin post explains why.
How is it handled?
- Dissolve in water or buffer. It will dissolve before you have finished adding the liquid.
- Stability. No cysteine, methionine, tryptophan or asparagine. The main degradation route for a glutamyl dipeptide is slow cyclisation to the diketopiperazine, which is accelerated by heat and by extremes of pH; keep stocks cold and near neutral. The reconstituted shelf-life post has the general rules.
- Storage. Lyophilized at minus 20 °C, aliquoted solutions frozen.
- Adsorption to plastic is minimal for a molecule this polar; standard tubes are fine above micromolar.
- Diluent. Water or buffer for in-vitro work; reconstitution solution only where a preserved multi-entry stock is wanted.
Frequently asked questions
Is vilon a protein?
No. It is a dipeptide, two amino acids. Proteins are hundreds. A dipeptide has no fold, no tertiary structure and no stability problems of the kind proteins have.
Why does the certificate include a sterility test?
Because the laboratory ran one for this lot. Not every lot on the site carries sterility; it is listed when it was tested. It establishes that no viable organisms were detected in the sample cultured, which is a different question from endotoxin.
Can purity by HPLC be trusted for a molecule this small?
As one line among six, yes. The retention time of 1.56 minutes means the peak sits near the solvent front where polar impurities would co-elute, so the identity-by-mass line and the content line carry more weight than they would for a longer peptide.
What is 20 mg of vilon in moles?
72.6 micromoles. It is the largest molar amount in any single vial on the site.
Is vilon the same as Thymalin?
No. Vilon is the synthetic dipeptide. Thymalin is the name of a bovine thymus extract from the same programme, and the catalogue product sold under that name has a certificate mass of 858.8, which is not a dipeptide. The thymalin versus thymulin post deals with that mass.
References
- PubChem, National Library of Medicine. Lysyl-glutamic acid, CID 7010502, C11H21N3O5, 275.3 g/mol, CAS 45234-02-4. Read 2 October 2026. pubchem.ncbi.nlm.nih.gov/compound/7010502
- Anisimov VN, Khavinson VK. Peptide bioregulation of aging: results and prospects. Biogerontology 2010;11(2):139-149. doi.org/10.1007/s10522-009-9249-8
- Bioviridian Inc. Certificate of analysis COA4861, lot VILON20-0528, issued 17 June 2026. Verification code on the certificate. bioviridians.com/coa-search.html
Every product mentioned is sold for laboratory research use only and is not for human or animal use. Nothing on this page describes or recommends use of the material sold here in humans or animals.
