What is Testagen?

What sources report

Testagen is four amino acids long: lysine, glutamic acid, aspartic acid and glycine, in that order.² PubChem files it as H-Lys-Glu-Asp-Gly-OH, with the formula C17H29N5O9 and a molar mass of 447.4 g/mol.¹ A 2021 review from Vladimir Khavinson's group lists KEDG (Testagen) in a table of short peptides and assigns it to regulation of male reproductive system function.³ Bird studies from another Russian group describe the same sequence differently, as a peptide synthesized from the amino acid makeup of anterior pituitary extracts.⁸ The sources we reviewed do not reconcile the two accounts.

Cell and test-tube work

In a 2011 study, fluorescent-labeled Testagen entered the cytoplasm, nucleus and nucleolus of HeLa cells, and in test-tube work it appeared to bind preferentially to short DNA strands containing CAG.² The authors propose that this kind of peptide and DNA binding is a form of epigenetic control.² In 2013 fluorescence experiments, KEDG bound wheat histones H1, H2B, H3 and H4, the proteins DNA is wound around; the developers suggest histone binding can make genes more available for transcription.⁵³ A 2023 computer docking study predicted that KEDG is among the strongest binders of the transporters LAT1, LAT2 and PEPT1, a possible route into cells, though this was modeling only.⁶ One more paper is materials chemistry, not biology: KEDG reduced copper corrosion in salt water with about 86% efficiency.⁴

Animal studies

The peer-reviewed animal studies we located for KEDG are bird studies.⁷⁸⁹ In chickens whose pituitary gland was removed soon after hatching, 40 days of KEDG or AEDG was followed by higher thyroid-stimulating hormone and thyroid hormone levels and recovery of thyroid structure; the abstract does not separate the two peptides.⁷ A 2011 follow-up in young chickens and old hens found that KEDG or AEDG (Epithalon's sequence²) reduced thyroid hormone and structural disturbances, with a weaker hormonal effect in old hens.⁸ In a 2013 study of young and old birds, both peptides aided recovery of thymus structure, KEDG more than AEDG.⁹

The developers' own report, published in a Russian drug reference rather than a peer-reviewed journal, adds rat data.¹⁰ In organ cultures, Testagen enlarged the growth zone of testis tissue explants by 54.1% from young rats and 40.6% from old rats, with no significant effect on 16 other tissues tested.¹⁰ In male rats made sterile by whole-body irradiation, Testagen given before irradiation partly preserved fertility: 40% of females housed with treated males were pregnant by day 45 and 59% by day 90, against 0% with untreated males.¹⁰

Human data

No peer-reviewed human study of Testagen appears in PubMed, and no trial of the peptide is registered on ClinicalTrials.gov.¹²¹³ The only human data located is the same developer report. It describes 48 men aged 54 to 68 with "male climacteric" who were randomized to standard care with oral Testagen capsules (27 men) or without them (21 men) for 20 days.¹⁰ Mean testosterone rose from 6.1 to 7.3 ng/mL in the Testagen group, against 6.5 ng/mL after standard care alone, and sperm count rose from 16 to 22 million per mL after one course.¹⁰ The report names no original journal and gives no full methods or statistics.¹⁰ It is the only source of testosterone data for Testagen, and none of it concerns injected Testagen.¹⁰¹²

Peptides and testosterone and Peptides and men's health set this evidence beside other compounds. Labs that work with the compound itself will find it on the product page: Buy Testagen.

Side effects

Human safety data for Testagen are minimal.¹⁰¹² The developers reported no side effects, complications or dependence in their 48-man oral capsule study.¹⁰ They also reported that preclinical testing found no general toxicity or accumulation at doses 10,000 to 15,000 times the recommended dose, and no allergic, immune-toxic, embryo-toxic or birth-defect effects.¹⁰ Those data were not published in a peer-reviewed journal, and no independent safety study was found.¹⁰¹²

Broader cautions from regulators and reviewers:

• Injected Testagen has never been studied in people; the only human report concerns oral capsules.¹⁰¹²
• Health Canada warns that unauthorized injectable peptides may cause infection, allergic reactions and other poor outcomes, may interact with other medicines, may contain high-risk ingredients or contaminants that are not listed on the label, and may not have been made or stored safely.¹⁶
• A 2026 review of gray-market peptide use names mislabeling, wrong potency, contamination, non-sterility and harmful impurities among the most immediate risks of products sold "for research use only", and notes that existing reporting systems may fail to detect harms from them.¹⁷
• A 2026 review of peptides in gerontology says Semax and Epitalon, two Russian peptides with decades of use there, lack independent validation and systematic safety surveillance through Western regulatory frameworks, and that the absence of serious adverse events in the published Russian literature is not enough to establish safety.¹⁸

Dosage information

No human dose of Testagen is established: it has no FDA label and no registered trial, and the only human report used oral capsules in an unreplicated developer study.¹⁴¹³¹⁰ No dose for injection has been studied in people.¹⁰¹² The table records what published studies used; these figures describe the studies and are not doses for people.

Injection schedules quoted on seller pages have no published study or drug label behind them.¹²¹³¹⁴

Reconstitution and storage

The research vial holds freeze-dried Testagen powder.²³ The supplier says to keep the dry vial refrigerated and away from light, and to keep a vial mixed with bacteriostatic water cold and use it within 30 days.²³ Those are supplier statements; we found no published stability data for Testagen in solution.¹² For comparison, the Russian oral supplement, a capsule rather than a vial, is labeled for storage in a dry, dark place at 2 to 25 °C with a 5-year shelf life.¹¹

General guidance from peptide makers fits this sequence. GenScript lists Lys, Glu and Asp among residues that draw moisture from the air, and KEDG contains all three; it recommends a tightly capped vial kept in a desiccator.²⁴ GenScript also names Asp among residues that shorten a peptide's life in solution.²⁴ Bachem advises against storing peptides in solution and says that solutions kept for storage should be split into portions and frozen below -15 °C.²⁵ The lab steps (diluent choice, sterile technique, concentration math) are in the reconstitution guide, the reconstitution calculator does the arithmetic, and How to store peptides covers storage in more depth.

Regulatory status

Testagen is not an approved drug in the United States, and a DailyMed search returns no label for it.¹⁴ It is not on FDA's list of compounding substances that may present significant safety risks (Category 2), or on that page's list of withdrawn nominations, in the version current as of April 22, 2026.¹⁵ Under 21 CFR 312.160, an unapproved new drug may be shipped only for test-tube or laboratory animal research, labeled "Not for use in humans", and the shipper must use due diligence to confirm that the buyer regularly does such research.¹⁹

• Russia: a product called Testagen is sold as a dietary supplement, not a drug. Each oral capsule holds 100 micrograms of a peptide complex of lysine, glutamic acid, aspartic acid and glycine, made by Firma-Vita.¹¹
• Canada: Testagen was not among the products named in Health Canada's 2025 advisory on the seller Canada Peptide. Health Canada states that injectable peptides are regulated as prescription drugs there and that selling unauthorized drugs is illegal.¹⁶
• Sport: WADA's 2026 list does not name Testagen, but class S0 bans at all times any pharmacological substance not covered elsewhere on the list that has no current approval by any government health authority for human therapeutic use.²⁰ The 2027 list, approved September 10, 2026, adds "peptides" to the examples of unapproved substances in S0.²¹²²
• Name clash: Testagen TDS-Testosterone, a testosterone product whose study is registered as NCT02733133, is unrelated to the peptide.¹³

How Testagen compares with related peptides

• Epithalon is Ala-Glu-Asp-Gly (AEDG), so it differs from Testagen only in the first amino acid.² The bird studies called KEDG an anterior-pituitary peptide and AEDG a posterior-pituitary peptide, and KEDG did more to restore thymus structure.⁸⁹
• Pinealon, the tripeptide Glu-Asp-Arg, was tested beside Testagen and Epithalon in the 2011 HeLa cell study, and all three appeared to bind preferentially to CAG-containing DNA.²
• Testosterone: Testagen is a four-amino-acid peptide, not a hormone, and contains no testosterone.¹¹³