Testagen: what the studies show, status and safety
Summary
Testagen is a synthetic chain of four amino acids, Lys-Glu-Asp-Gly, made at a St Petersburg institute and sold as a peptide for the testes. Every reviewed animal study published on it concerns the pituitary gland and the thyroid, and so does the only patent found for it, with the head of the originating group named as a co-inventor. The testis label rests on two review tables and on an unreviewed account by the developers themselves. No registered study in people was found in any database searched, and it is approved as a medicine in none of the markets checked.
Key findings at a glance
- The sequence is solid. Three independent papers give Lys-Glu-Asp-Gly, and the chemical record adds the formula C17H29N5O9 and a mass of 447.44 g/mol [1], [2], [14].
- Every reviewed animal study is about the pituitary and thyroid. Four papers from one group describe the peptide as built on the make-up of the front lobe of the pituitary gland and measure thyroid hormones [4], [5], [6], [7].
- The only patent found claims the same axis. RU2325397 claims the peptide as a medicine stimulating thyroid-stimulating hormone and thyroid hormones. Khavinson is named among its inventors [8].
- The testis label is backed by three papers, none of which looked at reproduction. One is about wheat histones, one about immune cell differentiation, and one about two other peptides in mouse hearts [9], [15], [18].
- In the second review table, the row has no reference at all. Every neighbouring row carries one; the Testagen row is the only one that does not [10].
- No registered study in people was found. A registry query for the peptide code returned zero, and the single hit under the trade name belongs to a testosterone lotion [11].
- The newest reviewed paper is about copper. A 2025 study measured the peptide as a corrosion inhibitor on copper surfaces, reaching roughly 86 per cent efficiency [14].
What it is
Testagen is a laboratory-made peptide of four amino acids, sold as capsules in Russia and as a research chemical in the West. It comes from the St Petersburg Institute of Bioregulation and Gerontology, the group around Vladimir Khavinson [12], [13].
The group calls molecules of this kind peptide bioregulators: short synthetic chains said to carry the active core of an animal organ extract. That is a house term of the institute. It appears in no pharmacopoeia and in no regulator's classification [9], [12].
Where the organ in question lies is exactly what the sources disagree about. The Russian product describes peptides with a tissue-specific effect on testis cells. The reviewed animal work describes a peptide of the front lobe of the pituitary gland [4], [12].
Quick facts
| Field | Value | Ref |
|---|---|---|
| Chain | Lys-Glu-Asp-Gly, four amino acids | [1], [2] |
| Formula and mass | C17H29N5O9, 447.44 g/mol | [1] |
| Structure key | InChIKey HKEYFJLTNCUNAD-DCAQKATOSA-N | [1] |
| Code in the literature | KEDG | [2], [10] |
| Chemical record | PubChem CID 123863700; MeSH concept 67560777 | [1], [19] |
| CAS registry number | None confirmed; the number printed by sellers appears only in trade catalogues | [1], [19], [35] |
| Code with the American regulator | None found | [20] |
| Entry in the open knowledge base | None found; none in the curated drug databases searched either | [33], [34] |
| How long it lasts in the body | No published value found, for any route | [32] |
| Registered studies in people | None found | [11] |
| Approval status | Not approved as a medicine anywhere | [21], [24], [27] |
| Sold as | Capsules and tablets as a food supplement in Russia, 20 mg vials of powder in the West | [12], [13], [35] |
| Originating group | St Petersburg Institute of Bioregulation and Gerontology | [3], [13] |
How it works
Nobody knows. No receptor has been reported, no dose-response relationship in a mammal was found in the literature searched, and no reviewed study describes what the peptide does inside a testis.
The explanation offered by the originating group runs in three steps. The peptide would be carried into the cell, would reach the nucleus, and would attach to DNA and to histones, changing which genes are read. Each step deserves a separate look.
- Getting into the cell. Computer docking put the peptide among the better-fitting ligands of the amino acid carriers LAT1 and LAT2 and of the peptide carrier PEPT1. The authors call their own results preliminary only, and no transport was measured [17].
- Reaching the nucleus. Labelled peptide was seen in the cytoplasm, the nucleus and the nucleolus of HeLa cells. That is a picture of where it went, not of what it did [2].
- Attaching to DNA. In cell-free tests the peptide bound short DNA stretches. Which stretch it bound depended on the sequence and even on whether a cytosine carried a methyl group, with a preference for CAG [2].
- Attaching to histones. It bound the front ends of histones H1, H2B, H3 and H4. Those histones came from wheat, and the authors found no matching sequences in the wheat core histones [15].
- Acting through the pituitary. In birds whose pituitary gland had been removed, the peptide raised thyroid-stimulating hormone and thyroid hormones and prevented the shrinking of the thyroid [4], [7].
Docking scores for KEDG against 26 ultrashort peptides, with rank out of 26 in brackets: LAT1 sixth, LAT2 ninth, PEPT1 seventh, PEPT2 twenty-third. A more negative value means a better calculated fit; a positive value means no fit. The authors describe the results as preliminary only. Source [17].
A size problem sits underneath all of this. Four amino acids carry very little information, far too little to single out one gene in a whole genome. All four also circulate freely in blood as ordinary amino acids.
The gap between the two halves of the story is the point. The binding work says nothing about which organ, and the animal work that does name an organ names the pituitary gland, not the testes [2], [5], [15].
What the studies found
About eleven papers mention this peptide at all. Two are cell-free binding studies, four are experiments in birds, two are computer models, one is about copper, and the rest are reviews from the originating group [32].
Counts as of 17 September 2026. Literature searches returned 2 records under the trade name, 10 under the sequence and 3 under the peptide code; the registry query for the code returned zero. Sources [4], [5], [6], [7], [11], [32].
The pituitary and thyroid work
Animal data Chicks had their pituitary gland removed shortly after birth, which shrinks the thyroid and lowers its hormones. The peptide was given for 40 days. It raised thyroid-stimulating hormone and thyroid hormones and restored the structure of the gland [4], [7].
Animal data Two further papers repeat the pattern in one-year-old and five-year-old hens. The recovery was clearer in young birds than in old ones. Exact figures are not accessible, because none of these full texts is open [5], [6], [7].
Animal data In the same bird model, the peptide also helped the thymus regain its structure. It did so more strongly than its sister peptide from the back lobe of the pituitary gland [16].
All four papers come from one group at one academy. All four describe the peptide as built on the amino acid make-up of the front lobe of the pituitary gland [4], [5], [7].
The testis findings
Unreviewed developer account In organ cultures, the growth zone of testis tissue from young rats rose by 54.1 ± 3.1 per cent (p<0.05) and from old rats by 40.6 ± 2.3 per cent. Fourteen other tissues showed no significant growth [3].
That single screen is the only experimental result found behind the testis label. It names no concentration and no number of cultures, it was published by the developers, and it has not been through review [3].
Unreviewed developer account In irradiated male rats paired with females, pregnancy rates of 40 per cent on day 45 and 59 per cent on day 90 are reported when the peptide was given beforehand, and 14 per cent on day 30, 42 per cent on day 60 and 61 per cent on day 90 when it was given afterwards, against zero in controls throughout. No dose, no route, no animal numbers and no statistics are given [3].
The one account in people
Unreviewed developer account 48 men aged 54 to 68 were split into 27 who received the capsules and 21 who did not, for 20 days by mouth. Neither group was blinded, and both also received adaptogens, vitamins and sometimes tranquillisers [3].
The reported figures are serum testosterone of 6.1 ± 0.4 ng/ml before treatment, 6.5 ± 0.2 after standard treatment and 7.3 ± 0.3 after standard treatment plus the capsules. Sperm concentration is given as rising from 16 to 22 million per ml [3].
Four things make those numbers unusable as evidence of an effect. There are no p-values and no confidence intervals. There is no blinding and no placebo. The authors are the developers. And the account never states which substance was tested, calling it only a short peptide [3].
One detail deserves attention on its own. LH fell from 3.71 ± 0.14 to 3.08 ± 0.09 and FSH from 2.95 ± 0.18 to 2.21 ± 0.14 while testosterone was said to rise. The account does not explain that combination [3].
Where the evidence points elsewhere
Materials science The newest reviewed paper on this peptide is about copper. It measured adsorption on copper surfaces in salt water and reports a corrosion inhibition efficiency of about 86 per cent, with a free adsorption energy of −30.86 kJ/mol [14].
That work is cited here for what it is. It confirms the identity of the molecule and that it can be synthesised, and it carries no information about any effect in a living body [14].
What is still unknown
- How much reaches the blood after swallowing or injection, how it is distributed and how fast it is broken down. No such measurement was found for any species [32].
- What it does in mammalian testis tissue in a reviewed experiment. Nothing of the kind was found in the searches behind this page [9], [32].
- Whether any of the bird findings repeat outside the group that produced them. No independent replication was found [32].
- What the doses in the animal work actually were. Those full texts are not open, so the figures cannot be read [32].
- Which substance the human account concerns: the pure four-part peptide, or the peptide complex declared on the Russian label [3], [12].
Side effects and safety
There is almost nothing to report, and that is the finding rather than a reassurance. No study was designed to collect safety data, and no reporting route exists for a substance sold outside pharmacies.
- No side effects reported in 27 people over 20 days, stated by the developers in their own account. At that size, an effect occurring in fewer than about one in ten people cannot be ruled out [3].
- One contraindication on the Russian label: individual intolerance of the ingredients. That is the standard wording for Russian food supplements, not a substance-specific assessment [12], [13].
- No entry in the American adverse event database. A query returned nothing, which is expected for a substance with no American licence and no pharmacy route. It means there is no reporting path, not that nothing happens [21].
- A hormone pattern that is not explained. LH and FSH fell while testosterone was said to rise. Such a pattern would fit a direct effect on the testes, but equally a damping of the signal from the brain [3].
- A toxicity statement that cannot be checked. The developers state that huge multiples of the intended amount caused no accumulation and no organ changes. No species, no numbers, no route and no observation period are given [3].
What is missing
None of the following was found in the literature and register searches behind this page [32].
- No modern toxicology: no lethal dose, no repeat-dose study to any standard, no genotoxicity and no reproductive toxicology. The last gap matters, because reproduction is what the substance is sold for [32].
- No safety data at all for injection. The only documented human use is by mouth [3], [13].
- No data on long-term use beyond 30 days, on interactions, on pregnancy, on children or on reduced liver and kidney function [32].
- No independent purity analysis. Sellers state 99 per cent in one catalogue and 95.97 per cent in another, both unverified [35].
- No sterility or endotoxin data for the vials sold as injectable material, which are labelled not for human use [35].
Doses used in studies
The doses below are simply what the cited studies gave, listed so that the results can be understood. They are not advice on how to use anything. The one line that concerns people comes from an unreviewed developer account rather than from a registered study.
| Study | Model | Amount | Route | Duration | Ref |
|---|---|---|---|---|---|
| Developer account in people, not a registered study | 48 men aged 54 to 68, 27 of them given the capsules | 1 to 2 capsules per intake; the label puts 100 µg of peptide complex in a capsule, so 200 to 400 µg a day | By mouth, with meals | 20 days | [3], [13] |
| Russian food supplement label | People, general statement on the package | 1 to 2 capsules of 100 µg, so 100 to 400 µg a day | By mouth | Courses of 20 to 30 days, repeated after 4 to 6 months | [12], [13] |
| Developer toxicity statement | Rat | No figure given; multiples only, up to 10,000 to 15,000 times the intended amount | Not stated | Not stated | [3] |
| Bird studies of the pituitary and thyroid | Chicks and hens with the pituitary gland removed | Not accessible; the full texts are closed | Described as injected in one report, otherwise not stated | 40 days | [4], [5], [7], [16] |
| Binding and uptake work | HeLa cells; cell-free DNA and histone preparations | Not accessible in the abstracts | Added to the fluid | Not stated | [2], [15] |
Three limits apply to every line. The only documented human exposure is a peptide complex taken by mouth, not the pure peptide and not injected. The animal amounts cannot be read at all. Nothing here can be converted to body weight [3], [12], [32].
The gap to what circulates in trade is large. One guide names 20 mg a day by mouth and 2 to 5 mg a day injected. That is 50 to 200 times the documented daily amount, by a route for which no approved product and no toxicology was found in any market checked [36].
Development and approval status
A patent, eleven papers, no development programme
- 2006Patent filed in Russia for a medicine stimulating thyroid hormonesClaims Lys-Glu-Asp-Gly; Khavinson among the inventors, ref [8]
- May 2008Russia registers a capsule food supplementCertificate 77.99.23.3.U.4254.5.08 of 27 May 2008, refs [12], [13]
- 2008-2013Four bird studies on the pituitary and thyroid, plus one on the thymusAll from one academy, refs [4], [5], [6], [7], [16]
- 2011-2013Two cell-free binding studies on DNA and on wheat histonesUptake into HeLa nuclei; no biological endpoint, refs [2], [15]
- 2021-2023Review tables assign the peptide to the male reproductive systemBacked by unrelated papers, or by none at all, refs [9], [10], [17]
- 2025Newest reviewed paper: corrosion protection on copperAbout 86 per cent inhibition efficiency, ref [14]
- 17 September 2026Registers checkedNo approval in the markets checked, no registered study found, no regulator code, refs [11], [20]
No development programme behind Testagen was found. No sponsor filing, no phase of testing and nothing pending turned up in the registers searched. What exists is a 2006 patent, a thin line of laboratory papers, and a capsule sold as a food supplement [8], [11].
| Market | Status | Note | Ref |
|---|---|---|---|
| United States | Not approved | No substance record and no code found; no nomination in the list for pharmacy compounding | [20], [23] |
| European Union | Not approved | No authorisation and no procedure found; the agency's search returned no readable list | [24] |
| Germany | Not approved | An unlicensed injectable preparation may not be placed on the market | [24] |
| United Kingdom | Not approved | The register returned only a page shell, so this rests on every other check | [25] |
| Australia | Not approved | Absent from the Poisons Standard, which is not permission | [26] |
| Canada | Not approved | Both database queries returned empty lists while a control query worked | [27] |
| Switzerland | Not approved | No authorised preparation identified; only a Swiss trade listing was found | [28], [35] |
| Russia | Not approved as a medicine | Registered in May 2008 as a food supplement in capsules and tablets, taken by mouth | [12], [13], [29] |
Two rows need care. The Australian entry means the substance was never scheduled, not that it may be used [26]. The Russian row is the one sellers lean on, and it is a food registration, not a medicine licence [12], [29].
The Russian registration also has a date problem. The certificate is from May 2008, and it comes from two pharmaceutical reference works rather than from the registry itself. Whether it is still in force in 2026 could not be verified [12], [13].
Two American records turn up under the name and belong to something else. A single label entry and a single registry entry both describe a testosterone lotion applied to the skin, made by an unrelated company [11], [21], [22].
Anti-doping
Testagen is banned at all times, in and out of competition. Category S0 of the 2026 Prohibited List covers "any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use" [30].
The name does not appear on the list, and that is not a gap. The peptide is licensed in none of the markets checked, and a Russian food supplement registration is not an approval for human therapeutic use [12], [30].
A stricter reading is also defensible and should be stated plainly. Section S2.2.1 is an open category covering testosterone-stimulating peptides in males, and that is exactly the property the substance is marketed with [30].
The difference matters for an athlete. Everything in S0 counts as a specified substance, which softens the penalty; substances in S2 do not, which hardens it. Either way the use is a violation [30].
German anti-doping law reads differently again. Its annex names banned substances one by one and has no catch-all heading for testosterone-stimulating peptides, so this peptide is not covered there [31].
No published method for detecting it in a sample was found in this search. That changes nothing about the ban. Further detail is in the overview of peptides banned in sport.
Compared with related peptides
| Peptide | Relation to Testagen | What the checks behind this page found |
|---|---|---|
| Testagen | — | Lys-Glu-Asp-Gly, 447.44 g/mol; four reviewed animal studies, all on the pituitary and thyroid, none in people [1], [4], [7] |
| Epitalon | Differs by one building block, AEDG against KEDG | Stands for the back lobe of the pituitary gland in all four bird studies; a far larger literature of its own [4], [7] |
| Chonluten | Three of four building blocks shared, EDG against KEDG | Sold in the same Russian catalogue for lung tissue; same kind of table-entry organ label [10] |
| Livagen | Same first two building blocks, KEDA against KEDG | From the same laboratory, labelled for the liver; carries a reference in the table where Testagen carries none [10] |
| Ovagen | Sister peptide of the same series, EDL | Sold as a liver peptide while every reviewed experiment on it was done on kidneys [10] |
| Testoluten | Sold for the same organ, but a different kind of product | An animal tissue extract, a mixture of many substances, not a single defined peptide [12] |
The comparison is not about strength. It shows a family of near-identical short chains, each assigned to a different organ. Those labels rest on the same kind of table entry rather than on organ-specific experiments [9], [10].
The most instructive row is Epitalon. It differs from Testagen in a single building block and appears beside it in every one of the four bird studies. Its own label is the other lobe of the same gland [4], [7].
The Testoluten row explains a common mix-up. Buyers who read about a testis extract and then buy a four-amino-acid peptide are not buying a concentrated version of the same thing [12].
Common misconceptions
- "Testagen is derived from testis tissue." It is synthetic. Even the sources that assign it to the testes claim only derivation from the make-up of a tissue extract. The reviewed papers name that extract as the front lobe of the pituitary gland [4], [5].
- "The reviews confirm that it regulates the male reproductive system." One review backs that line with three papers: one on wheat histones, one on immune cell differentiation and one on two other peptides in mouse hearts. In the second review, the row carries no reference at all [9], [10], [15], [18].
- "There is a clinical trial of Testagen." The single registry hit is a testosterone lotion applied to the skin, registered in 2016 by an unrelated company, with a start date still in the future. A query for the peptide code returns zero [11].
- "It is sold in Russia, so it has been approved there." It is registered there as a food supplement, a category that involves no test of whether a substance works. No injectable form was found in the Russian registrations [12], [13], [29].
- "The Russian data apply to the peptide sold in the West." The Russian label declares a peptide complex, and the human account never names the sequence. The West sells the pure four-part peptide [3], [12].
- "It caused no side effects, so it is safe." That sentence comes from 27 people over 20 days, in an unblinded account written by the developers. For the injected form no safety data of any kind was found [3].
- "A new study on Testagen was published in 2025." It was, and it is about corrosion protection on copper surfaces. Quoting it without naming its subject gives a false impression of the research base [14].
- "It is a food supplement, so athletes are safe." The 2026 Prohibited List bans it at all times, and a food supplement registration in one country is no protection against a ban [12], [30].
- "Its CAS number proves it is a registered substance." The number printed by sellers appears only in trade catalogues. The chemical record holds no registry number, and the medical concept record has no such field [1], [19], [35].
Frequently asked questions
What is Testagen?
A synthetic chain of four amino acids, lysine, glutamic acid, aspartic acid and glycine, written Lys-Glu-Asp-Gly or KEDG. It comes from the St Petersburg Institute of Bioregulation and Gerontology. Russia registered a capsule food supplement of that name in 2008; the West sells the pure peptide as a research chemical in vials.
Is Testagen really a testis peptide?
The reviewed literature does not support that label. All four reviewed animal studies describe the peptide as built on the amino acid make-up of the front lobe of the pituitary gland, and they measure thyroid hormones. The only patent found for it claims the same axis. The testis label appears in two review tables and in an unreviewed account written by the developers.
Has Testagen been tested in people?
No registered study was found in any database searched. A registry query for the peptide code returned zero. One account of use in people exists: 48 men aged 54 to 68, of whom 27 received the capsules for 20 days, published by the developers in a pharmaceutical reference collection. It was not registered, not blinded, not placebo-controlled and reports no p-values.
Why does a trial registry show a hit for Testagen?
Because the name belongs to a second, unrelated product. Testagen TDS Testosterone 5% is a testosterone lotion applied to the skin, made by a company with no link to the peptide. That product is behind the single registry entry and the single American label record found under the word Testagen.
Is Testagen approved as a medicine anywhere?
No, in none of the markets checked, and not in Russia either. The only official entry found anywhere is a Russian food supplement registration from May 2008 for capsules and tablets taken by mouth. Whether that registration is still in force in 2026 could not be verified. A food supplement registration is not a medicine licence and involves no test of whether something works.
What are the side effects of Testagen?
Nobody has collected them properly. The only human account reports no side effects in 27 people over 20 days, written by the developers themselves. At that size, an effect occurring in fewer than about one in ten people cannot be ruled out. For the injectable form sold in the West no safety data was found at all.
How is Testagen different from Epitalon?
They differ in a single building block: Testagen begins with lysine, Epitalon with alanine, and the remaining three are identical. The two were tested side by side in all four bird studies, where they stand for the front and the back lobe of the pituitary gland. Epitalon has a far larger literature of its own, and its findings do not carry over.
Is Testagen banned in sport?
Yes, at all times, in and out of competition. It is not printed on the 2026 Prohibited List by name. Category S0 covers any drug-like substance that no health authority has approved for use in people, which fits it exactly. A stricter reading is also arguable, because section S2.2.1 is an open category for testosterone-stimulating peptides in males.
What is the newest published work on Testagen?
A 2025 paper from a Romanian university on corrosion protection. It measured how the peptide sticks to copper surfaces in salt water and reports an inhibition efficiency of about 86 per cent. It is materials science, it confirms that the molecule exists and can be made, and it says nothing about any effect in a body.
Why does this page give amounts for Testagen but no schedule?
Because the documented amounts describe what sources reported, not what anyone should do. The only figures attached to people are 100 to 400 micrograms a day of a peptide complex, taken by mouth as capsules. The amounts circulating in trade are 50 to 200 times larger and often injected, a route for which no approved product and no safety work was found in any market checked.
Sources
- PubChem. Compound CID 123863700, H-Lys-Glu-Asp-Gly-OH, C17H29N5O9, molecular weight 447.4 g/mol (447.44 as the computed average mass printed in trade listings), exact mass 447.19652752, InChIKey HKEYFJLTNCUNAD-DCAQKATOSA-N, XLogP −8.1, topological polar surface area 251 Ų, complexity 670. The synonym list holds one entry, a patent-derived code, and no registry number. Name queries for the trade name, the sequence and the peptide code each returned not-found; only the written-out form resolved. Retrieved 17 September 2026. https://pubchem.ncbi.nlm.nih.gov/compound/123863700
- Fedoreyeva LI, Kireev II, Khavinson VKh, Vanyushin BF (2011). 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 (Moscow) 76(11):1210-1219. PMID 22117547. DOI 10.1134/S0006297911110022. Names the peptide as "testagen, Lys-Glu-Asp-Gly". Reports label in cytoplasm, nucleus and nucleolus, sequence-dependent and methylation-sensitive binding with a preference for CAG-containing stretches, and no biological endpoint.
- Khavinson VKh, Ryzhak GA. Clinical and experimental study of the peptide bioregulator Testagen. Library of the Russian medicines reference work RLS, urology section, state of 18 August 2021, retrieved 17 September 2026. The only account of use in people anywhere: 48 men aged 54 to 68 with male climacteric syndrome, randomised 27 against 21, unblinded, without placebo, on top of adaptogens, vitamins and occasional tranquillisers, 1 to 2 capsules twice daily by mouth for 20 days. Testosterone 6.1 ± 0.4, then 6.5 ± 0.2, then 7.3 ± 0.3 ng/ml; LH 3.71 ± 0.14 to 3.08 ± 0.09; FSH 2.95 ± 0.18 to 2.21 ± 0.14; sperm concentration 16 to 22 million per ml; motility grade a plus b 39 to 54 per cent; live sperm 42 to 57 per cent; leucocytes 1.8 to 0.4 million per ml. No p-values and no confidence intervals are given, and the sequence of the tested peptide is never stated. The same document holds the organ culture screen, the irradiation model in rats and the toxicity statement. Not peer reviewed; written by the developers of the preparation.
- Kuznik BI, Pateyuk AV, Rusaeva NS (2008). 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. Bulletin of Experimental Biology and Medicine 145(1):104-107. PMID 19024016. DOI 10.1007/s10517-008-0033-6. States that the peptides were synthesised on the basis of the amino acid composition of pituitary cytomedins; reports raised thyroid-stimulating hormone and thyroid hormones after 40 days. Not open access, so the amounts given cannot be read.
- Kuznik BI, Pateiuk AV, Rusaeva NS, Baranchugova LM, Obydenko VI (2010). Effects of hypophyseal Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly synthetic peptides on immunity, hemostasis, morphology and functions of the thyroid gland in neonatally hypophysectomized chicken and one-year-old birds. Patologicheskaya Fiziologiya i Eksperimentalnaya Terapiya (1):14-18, in Russian. PMID 20731122. Assigns Lys-Glu-Asp-Gly explicitly to the anterior lobe and Ala-Glu-Asp-Gly to the posterior lobe of the pituitary gland.
- Kuznik BI, Pateiuk AV, Rusaeva NS, Baranchugova LM, Obydenko VI (2011). Effects of Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly peptides on hormonal activity and thyroid morphology in hypophysectomized mature and old birds. Advances in Gerontology 24(1):93-98, in Russian. PMID 21809626. Reports raised thyroid-stimulating hormone, T3 and T4, with recovery clearer in one-year-old than in five-year-old hens.
- Kuznik BI, Pateyuk AV, Rusaeva NS, Baranchugova LM, Obydenko VI (2011). 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. Bulletin of Experimental Biology and Medicine 150(4):495-499. PMID 22268052. DOI 10.1007/s10517-011-1177-3. Repeats the assignment of Lys-Glu-Asp-Gly to the anterior lobe; the normalising effect was weaker in old hens than in chicks. Not open access.
- Patent RU2325397, "Medicine stimulating thyrotrophic and thyroid hormones", filed 25 December 2006, published 2008. Inventors Kuznik BI, Patejuk AV, Rusaeva NS, Khyshiktuev BS, Khavinson VKh, Baranchugova LM, Maksimenja MV. Retrieved through Europe PMC patent records, 17 September 2026. Claims the application of the peptide Lys-Glu-Asp-Gly as a medicine stimulating the synthesis of thyroid-stimulating hormone by the pituitary gland and of thyroid hormone by the thyroid gland. The only patent found for this peptide.
- Khavinson V, Linkova N, Dyatlova A, Kuznik B, Umnov R (2021). Peptide regulation of gene expression: a systematic review. Molecules 26(22):7053. PMID 34834147. PMCID PMC8619776. DOI 10.3390/molecules26227053. Full text and reference list read 17 September 2026. The summary table carries the line "KEDG, Testagen — regulation of male reproductive system function" with three references. Resolved: the first is the wheat histone paper listed here as 15, the second the cell differentiation review listed here as 18, and the third a 2002 paper on Vilon and Epitalon in mouse hearts, which does not examine this peptide. None of the three studies a reproductive endpoint.
- Khavinson V, Linkova N, Dyatlova A, Kantemirova R, Kozlov K (2022). Transport of biologically active ultrashort peptides using POT and LAT carriers. International Journal of Molecular Sciences 23(14):7733. PMID 35887081. PMCID PMC9323678. DOI 10.3390/ijms23147733. Full text read 17 September 2026. The table of 26 ultrashort peptides carries the line "Testagen (KEDG) −21.92 Regulator of the male reproductive system". This is the only line in that table without a literature reference, while Cardiogen, Ovagen, Cartalax, Thymogen, Pancragen, Livagen, Epitalon and Crystagen all carry one.
- ClinicalTrials.gov, API v2, queried three ways on 17 September 2026. The peptide code returned a total count of zero. The sequence returned 23 records, all nutrition and amino acid studies where the full-text search matches the individual amino acids. The trade name returned exactly one record, NCT02733133, read in full: a single-dose pharmacokinetic study of Testagen TDS Testosterone 5% HypoSpray, a topically applied testosterone lotion, sponsored by Transdermal Delivery Solutions Corp, registered in 2016, still listed as not yet recruiting with a start date of 5 January 2027. No sponsor named Hudson Biotech appears. https://clinicaltrials.gov/api/v2/studies
- RLS encyclopaedia of medicines, food supplement entry for the Russian product, retrieved 17 September 2026. Category biologically active food supplement; maker named as a St Petersburg firm attached to the Russian Academy of Sciences; composition given as a peptide complex of lysine, glutamic acid, aspartic acid and glycine at 100 µg per capsule; stated effect a source of peptides with a tissue-specific action on testis cells; capsules of 0.2 g and 0.275 g and tablets of 0.16 g and 0.3 g; intake one to two capsules once or twice daily with meals; the only contraindication given is individual intolerance of the ingredients. Trade and reference record, cited as evidence of what is registered and claimed.
- Medi.ru, package information for the Russian product, retrieved 17 September 2026. State registration certificate number 77.99.23.3.U.4254.5.08 of 27 May 2008 and a sanitary-epidemiological conclusion of the same date. Capsule of 0.200 g containing 100 µg of the peptide complex, with cellulose, sucrose, lactose, starch and polysorbate as carriers. Courses of 20 to 30 days, repeated after 4 to 6 months. The indications advertised there are recovery of male reproductive function after infection and inflammation, support in male infertility and male climacteric complaints; they are reproduced here only as unsupported manufacturer claims, not as statements of this page. Whether the 2008 registration remains in force was not verifiable; the number comes from pharmaceutical reference works rather than from the registry itself.
- Dobriţescu A, Samide A, Cioateră N, Mic OC, Ionescu C, Dăbuleanu I, Tigae C, Spînu CI, Oprea B (2025). The inhibitory effect and adsorption properties of Testagen peptide on copper surfaces in saline environments: an experimental and computational study. Molecules 30(15):3141. PMID 40807317. PMCID PMC12348504. DOI 10.3390/molecules30153141. Describes the molecule as the tetrapeptide synthesised from lysine, glutamic acid, aspartic acid and glycine, written H-Lys-Glu-Asp-Gly-OH. Reports a corrosion inhibition efficiency of about 86 per cent on copper, a best fit to the Freundlich adsorption isotherm and a free adsorption energy of −30.86 kJ/mol. Materials science, not a biomedical study.
- Fedoreyeva LI, Smirnova TA, Kolomijtseva GY, Khavinson VKh, Vanyushin BF (2013). Interaction of short peptides with FITC-labeled wheat histones and their complexes with deoxyribooligonucleotides. Biochemistry (Moscow) 78(2):166-175. PMID 23581987. DOI 10.1134/S0006297913020053. Lys-Glu-Asp-Gly binds the front ends of wheat histones H1, H2B, H3 and H4. No matching sequences were found in the wheat core histones. A plant model system.
- Pateyk AV, Baranchugova LM, Rusaeva NS, Obydenko VI, Kuznik BI (2013). Effect of peptides Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the morphology of the thymus in hypophysectomized young and old birds. Bulletin of Experimental Biology and Medicine 154(5):681-685. PMID 23658898. DOI 10.1007/s10517-013-2029-0. Both peptides supported recovery of thymus structure regardless of age, with the anterior lobe peptide acting more strongly. Not open access.
- Khavinson VK, Linkova NS, Rudskoy AI, Petukhov MG (2023). Feasibility of transport of 26 biologically active ultrashort peptides via LAT and PEPT family transporters. Biomolecules 13(3):552. PMID 36979488. PMCID PMC10046148. DOI 10.3390/biom13030552. Docking tables read 17 September 2026: KEDG scores −34.05 at LAT1 and rank 6 of 26, −26.57 at LAT2 and rank 9, −22.72 at PEPT1 and rank 7, and +12.26 at PEPT2 and rank 23, where a positive value means no fit. The authors describe their results as preliminary only.
- Khavinson V, Linkova N, Diatlova A, Trofimova S (2020). Peptide regulation of cell differentiation. Stem Cell Reviews and Reports 16(1):118-125. PMID 31808038. DOI 10.1007/s12015-019-09938-8. Lists KEDG among peptides said to stimulate the directed differentiation of immune cells, without primary data of its own. Serves as one of the three references behind the reproductive line in source 9; the citation chain leads back to this review rather than to an experiment.
- US National Library of Medicine, MeSH supplementary concept record UID 67560777, "lysyl-glutamyl-aspartyl-glycine", mapped to oligopeptides, entry term Lys-Glu-Asp-Gly. The record holds no registry number field and no statement of action. Retrieved 17 September 2026.
- US Food and Drug Administration, Global Substance Registration System, 17 September 2026. Queries for the trade name and for the structure key each returned a total of zero. Without a substance record there is no regulator code. https://gsrs.ncats.nih.gov
- openFDA, 17 September 2026. The drug approvals interface returned not-found for the trade name, and the adverse event interface returned not-found as well. The label interface returned exactly one record, which belongs to the topical testosterone lotion of the same name and is marked for clinical trial use only. A control query for an approved medicine returned 18 records, so the search itself works. https://api.fda.gov/drug/label.json
- DailyMed, API version 2, 17 September 2026. A query on the trade name returned zero elements, database state 16 September 2026, while a control query for an approved medicine returned nine records.
- US Food and Drug Administration. Bulk drug substances nominated for use in compounding under section 503A. Downloaded 17 September 2026 and checked in full text, 282 lines, for the trade name, the peptide code and the sequence: no match in any of the three categories, so the substance was never even nominated. Control: three other short peptides return six matches in the same document. https://www.fda.gov/media/94155/download
- European Medicines Agency, medicines search for the trade name, 17 September 2026. No medicine results; the results area is driven by scripts and returned no readable list. Recorded as a nil result of medium confidence, supported by the absence of an international non-proprietary name and of an anatomical therapeutic code, which together make a central procedure very unlikely. German law adds a second question for the capsule form: a synthetic tetrapeptide without a meaningful history of consumption in Europe before 15 May 1997 would count as a novel food and would need its own authorisation, and none was found. https://www.ema.europa.eu/en/medicines
- MHRA Products, products.mhra.gov.uk, search for the trade name on 17 September 2026. The page returned only a loading message and no result list, so no control was possible. Recorded as an unverified gap rather than a nil result.
- Therapeutic Goods Administration, 17 September 2026. The register was unreachable, with a dropped connection on one address and a timeout on the other. No naming of the substance in the Poisons Standard was found through other routes. What decides the question in Australia is not naming: peptides without a register entry count as unapproved therapeutic goods, and import and supply are restricted accordingly. https://www.tga.gov.au/resources/artg
- Health Canada, Drug Product Database API, 17 September 2026. A brand name query and an active ingredient query for the trade name each returned an empty list, while a control query for an approved medicine returned a complete record. No drug identification number and no natural product number. https://health-products.canada.ca/api/drug/drugproduct/
- Swissmedic, research on 17 September 2026. No authorised preparation with this peptide or this name was identified, and no direct extract from the register of authorised preparations could be produced. The only Swiss hit was a trade listing offering the substance as a research chemical. Nil result of medium confidence.
- Russian state medicines register, grls.rosminzdrav.ru, retrieved 17 September 2026. The site works and offers searches by trade name and by active substance. No medicine entry for this product was found, which follows from its category: food supplements receive no medicine registration and do not appear in this register at all.
- World Anti-Doping Agency. The 2026 Prohibited List, sections S0 and S2.2.1, read in full text 17 September 2026. S0 reads: "Any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use … is prohibited at all times", and all substances in that class are specified substances. S2.2.1 opens with "Testosterone-stimulating peptides in males including, but not limited to", followed by named examples, which makes it an open category. Full-text checks for the trade name, the peptide code and the sequence returned no match; a control check for another peptide returned a match in the S0 section. https://www.wada-ama.org/en/prohibited-list
- German Anti-Doping Act, annex to section 2 paragraph 3, published as BGBl. 2023 I No. 67. Full text read 17 September 2026: neither the trade name nor the code nor the sequence appears. The peptide hormone section lists its substances one by one, and among the testosterone-related entries it names only chorionic gonadotrophin, luteinising hormone and the releasing hormone analogues. There is no open heading for testosterone-stimulating peptides. https://www.gesetze-im-internet.de/antidopg/anlage.html
- Literature searches, PubMed through the NCBI programming interface and Europe PMC, 17 September 2026. The trade name returned 2 records, the sequence 10 and the peptide code 3; Europe PMC returned 6 under the trade name, of which 3 concern unrelated subjects. After removing the mismatches, about eleven papers mention the peptide at all, and none of them examines an effect in the testis of a mammal in a reviewed journal. Open access status was checked for the bird studies: the relevant full texts are closed, so their doses are not readable.
- UniChem at the European Bioinformatics Institute, queried by structure key on 17 September 2026. Exactly two sources hold the structure, a patent chemistry collection and the chemical record cited here as source 1. No entry in the major curated drug and bioactivity databases.
- Wikidata, entity search for the trade name and for the sequence on 17 September 2026. Both result lists came back empty. No item was found.
- Western research-chemical listings, retrieved 17 September 2026. Freeze-dried powder in 20 mg vials, sequence given as H-Lys-Glu-Asp-Gly-OH, mass 447.44 g/mol, purity stated by one seller at 99 per cent or above and by another at 95.97 per cent, and a registry number printed that no database confirms. One listing describes the peptide only as a model compound for binding research and states plainly that it is not a drug, a dietary supplement or a therapeutic agent. All are sold as research material while presented in injectable form. Trade records, cited as evidence of what is sold and claimed. Not linked.
- Trade-adjacent guides listing amounts for this peptide, retrieved 17 September 2026. One names 20 mg a day by mouth and 2 to 5 mg a day injected, which is 50 to 200 times the only documented daily human amount, and assigns the peptide to the testes as a matter of fact. Nothing on those pages appears in any published source. Cited only as evidence that such figures circulate; their schedules are not reproduced here. Not linked.
Cite this page
The register checks and literature searches behind this page were run on 17 September 2026. For a substance whose reputation rests on an organ that no reviewed experiment has examined, the date on which those searches came back empty is part of the finding.
myPeptides Research & Editing. (2026). Testagen: what the studies show, status and safety. Version 1.0, 17 September 2026. myPeptides Peptide Register. Retrieved from https://mypep.app/peptides/testagen
How pages in this register are compiled and graded is described under methodology; the full register is at peptides.
| Version | Date | Change |
|---|---|---|
| 1.0 | 2026-09-17 | Initial publication |
Last verified: 17 September 2026. Next review: on the appearance of any reviewed experiment in testis tissue, any registered study in people, any independent replication, or any change in the anti-doping classification.