What is Testagen?
Testagen is the synthetic tetrapeptide Lys-Glu-Asp-Gly, usually written KEDG. It is one of the short "peptide bioregulators" developed by V. Kh. Khavinson and colleagues at the Saint Petersburg Institute of Bioregulation and Gerontology, whose review tables list the testagen peptide as a regulator of male reproductive system function (Khavinson et al., 2021; Khavinson et al., 2022), although no indexed study has examined it in reproductive tissue.
A Chita group that tested the same sequence describes it as designed from anterior pituitary extracts (Kuznik et al., 2011). The record is small, comes almost entirely from one research network and includes no human study. Disguised Alpha lists Testagen as a 20MG lyophilized research vial for laboratory research use only. Nothing on this page is guidance for use in people.
Testagen reference data
| Property | Value |
|---|---|
| Name | Testagen |
| Also called | KEDG, Lys-Glu-Asp-Gly, H-Lys-Glu-Asp-Gly-OH, lysyl-glutamyl-aspartyl-glycine |
| Sequence | Lys-Glu-Asp-Gly (KEDG), linear, with free amino and carboxyl ends |
| Compound class | Synthetic tetrapeptide; one of the Khavinson group's peptide bioregulators |
| Molecular formula | C₁₇H₂₉N₅O₉ |
| Molecular weight | 447.4 g/mol |
| PubChem CID | 123863700, filed as H-Lys-Glu-Asp-Gly-OH (the record does not list the name testagen) |
| Form | Lyophilized powder, 20MG per vial |
| Testing | No certificate is published for this listing yet, on the product page or in the COA portal (checked October 2026). Ask support for the certificate covering your lot |
Sequence, strength, format and storage come from the Testagen product page, which lists no formula or weight. Formula and weight come from PubChem CID 123863700, so the two sources do not conflict. MeSH, the National Library of Medicine's index, files the sequence as lysyl-glutamyl-aspartyl-glycine.
What the research covers
Published work on Testagen falls into five areas, summarized below with their models. PubMed indexes two papers under the name and about eight more under the sequence. Nearly all of the biology comes from Khavinson's institute or groups that publish with him, a Moscow laboratory and a Chita group led by his long-time co-author B. I. Kuznik, often in Russian journals or their English translations. All of it is bird, cell, cell-free or computer-model work.
The name and the tissue label
The name suggests the testes, and the group's 2021 systematic review lists KEDG under "regulation of male reproductive system function" (Khavinson et al., 2021). The three papers cited for that row are a histone-binding study, a review of cell differentiation and a mouse heart study of two other peptides. We found no indexed study of testagen in testicular tissue or cells.
The differentiation review lists KEDG among peptides it says stimulate immune cell differentiation (Khavinson et al., 2020). The Chita papers describe Lys-Glu-Asp-Gly as designed from anterior pituitary extracts, paired with Ala-Glu-Asp-Gly, the epitalon sequence, which they place in the posterior lobe (Kuznik et al., 2011). The St Petersburg group instead describes epitalon as designed from a pineal extract (see the epitalon research guide). Model: none (review and design statements).
Hypophysectomized birds
Five papers from Kuznik's group test KEDG side by side with Ala-Glu-Asp-Gly in chickens whose pituitary was removed. In neonatally hypophysectomized chickens, 40 days of the tetrapeptides was followed by higher thyrotropin and thyroid hormone levels and recovery of thyroid structure (Kuznik et al., 2008). A Russian-language report added that both peptides prevented thyroid atrophy and normalized immune and hemostatic parameters disturbed by the operation (Kuznik et al., 2010).
The response was weaker in older birds: in old hens than in chickens operated at 5 days (Kuznik et al., 2011), and in five-year-old than in one-year-old birds (Kuznik et al., 2011). In the thymus, both peptides promoted recovery of structure at every age, KEDG more than Ala-Glu-Asp-Gly (Pateyk et al., 2013). Thyrotropin is normally made by the anterior pituitary, and the abstracts do not say how complete removal was confirmed. Model: chickens and hens.
Nuclear entry, DNA and histone binding
In HeLa cells, a human cervical cancer line, fluorescein-labeled testagen, epitalon and pinealon appeared in the cytoplasm, nucleus and nucleolus. In cell-free tests, the unlabeled peptides quenched labeled DNA fragments to different degrees, and testagen, like epitalon and pinealon, appeared to prefer CAG-containing sequences (Fedoreyeva et al., 2011). KEDG was also one of six short peptides that bound fluorescein-labeled wheat histones H1, H2B, H3 and H4, with binding that varied with the histone, peptide and oligonucleotide (Fedoreyeva et al., 2013). Models: HeLa cells, synthetic DNA and purified plant histones.
Transporter docking
The developers' 2022 review gives KEDG a docking score at LAT1, an amino acid transporter (Khavinson et al., 2022). In a 2023 study of 26 short peptides, it ranked sixth at LAT1, ninth at LAT2 and seventh at PEPT1 but 23rd at PEPT2, and the authors grouped it with the most effective transporter ligands (Khavinson et al., 2023). We found no indexed measurement of KEDG transport. Model: molecular docking.
Copper corrosion
The one indexed paper from outside this network is materials chemistry: Romanian chemists reported that testagen inhibited copper corrosion in 0.9% sodium chloride by about 86% at 20 mg/L, with a free energy of adsorption of -30.86 kJ/mol that they read as mixed physical and chemical adsorption (Dobriţescu et al., 2025). It addresses no biological question. Model: copper electrodes plus computer simulation.
Key studies
- Kuznik BI, et al. "Effect of tetrapeptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the structure and function of the thyroid gland in neonatally hypophysectomized chickens." Bull Exp Biol Med. 2008. PMID 19024016. DOI 10.1007/s10517-008-0033-6. Hypophysectomized chickens: thyroid hormones and structure.
- Pateyk AV, 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. PMID 23658898. DOI 10.1007/s10517-013-2029-0. Hypophysectomized birds: thymus structure; KEDG the more active peptide.
- Fedoreyeva LI, et al. "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. PMID 22117547. DOI 10.1134/S0006297911110022. HeLa cells and labeled DNA: nuclear entry and a CAG preference.
- Khavinson VK, et al. "Feasibility of Transport of 26 Biologically Active Ultrashort Peptides via LAT and PEPT Family Transporters." Biomolecules. 2023. PMID 36979488. DOI 10.3390/biom13030552. Molecular docking at four transporters.
- Dobriţescu A, et al. "The Inhibitory Effect and Adsorption Properties of Testagen Peptide on Copper Surfaces in Saline Environments: An Experimental and Computational Study." Molecules. 2025. PMID 40807317. DOI 10.3390/molecules30153141. Copper electrodes in saline: about 86% inhibition.
Handling and storage of lyophilized Testagen
General laboratory practice for this peptide:
- Store the sealed vial at -20°C, protected from light, as shipped. After reconstitution, keep it at 2 to 8°C, protected from light, and avoid freeze-thaw cycles (per the product page).
- Let the vial reach room temperature before opening so moisture does not condense on the powder.
- With one basic and two acidic side chains and a PubChem-computed XLogP of -8.1, KEDG is strongly hydrophilic. Prepare stock in water or a neutral buffer and record the pH.
- Use single-use aliquots, set concentrations from measured content rather than the label figure, and record the lot number. See our peptide storage guide and reconstitution guide.
Frequently asked questions
What is Testagen?
Testagen is the synthetic tetrapeptide Lys-Glu-Asp-Gly from Khavinson's peptide bioregulator program. The group's review tables file it under male reproductive system function (Khavinson et al., 2021), but no indexed study has examined it in reproductive tissue. Its indexed research is bird, cell, cell-free, docking and corrosion work.
What is the KEDG peptide?
KEDG is the one-letter code for Lys-Glu-Asp-Gly, the sequence named Testagen (PubChem CID 123863700, 447.4 g/mol). It differs from epitalon, Ala-Glu-Asp-Gly, only in the first residue, and the two were tested side by side in the bird studies (Kuznik et al., 2008).
Has testagen been studied in testicular tissue?
Not in any indexed paper we found. The male reproductive label comes from the developers' review tables (Khavinson et al., 2022), not from a reproductive study.
Has Testagen been tested in people?
No human study of testagen or the KEDG sequence is indexed in PubMed, and it is not an approved drug in the United States (no Drugs@FDA record as of October 2026).
How strong is the evidence?
Weak. There are about ten indexed records, nearly all from Khavinson's institute or groups that publish with him; two are in Russian and five in English editions of Russian journals. The one outside paper concerns copper corrosion (Dobriţescu et al., 2025).
Where can researchers buy Testagen?
Disguised Alpha lists Testagen for laboratory research as a 20MG lyophilized vial: Testagen. The product page shows current availability and certificate status.
Related compounds and guides
- Epitalon (Ala-Glu-Asp-Gly) and its research guide
- Vesugen (Lys-Glu-Asp) and its research guide
- Pinealon (Glu-Asp-Arg) and its research guide
- Cardiogen (Ala-Glu-Asp-Arg) and its research guide
- Peptide bioregulators explained
- Peptide bioregulators list, A to Z
- COA portal, by lot
This product is for research use only. It has not been evaluated for safety or effectiveness in humans. Not for human consumption. All products are intended for laboratory research purposes only.