F tier · safety concern
Testagen's sequence is confirmed as Lys-Glu-Asp-Gly, but only two PubMed-indexed papers name it — one a HeLa nuclear-uptake experiment, the other a 2025 copper-corrosion-inhibition study — and the trials that a ClinicalTrials.gov search for 'Testagen' returns belong to an unrelated topical testosterone product.
testagen
Testagen is the Khavinson tetrapeptide Lys-Glu-Asp-Gly, described by the originating group as an endocrine-system bioregulator and sold on the research market as a testicular or testosterone-support peptide. Its published biology amounts to a single experiment showing that fluorescently labelled KEDG enters HeLa cell nuclei and binds particular DNA motifs. The only other indexed paper naming Testagen is a 2025 materials-chemistry study of its performance as a copper corrosion inhibitor.
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available as a research reagent
≥ 98% HPLC · lyophilised powder · batch certificate published. Grade F above is our own and is not adjusted because we stock it.
the explanation
Testagen is a four-amino-acid peptide sold as a testosterone or testicle peptide. Its actual published biology is a single experiment showing the peptide can get into a cell nucleus and stick to DNA. The most recent scientific paper about it is not about the body at all: it tests how well the peptide stops copper from corroding in salt water. If you search the clinical trials registry for Testagen you do find trials, but they are for an unrelated testosterone skin gel that happens to share the name.
regulatory status
No medicinal approval anywhere; unlicensed in the UK; name shared with an investigational testosterone gel
The peptide Testagen has no marketing authorisation as a medicine in the UK, EU or US, and no MHRA, EMA or FDA assessment exists. A ClinicalTrials.gov query for 'Testagen' does return a registry record, but it is a pharmacokinetic skin-transference study of Testagen TDS-Testosterone, a topical testosterone product from a US delivery-technology company, and has nothing to do with the peptide; there are zero registered studies of the peptide itself. The peptide is not named on the WADA Prohibited List, although exogenous testosterone is prohibited, so the shared name is a compliance hazard in sport. In the UK the peptide is not a licensed medicine, not a prescription-only medicine, not a controlled drug and not an authorised supplement ingredient; lawful supply is as a laboratory reagent not for human consumption.
how it works · proposed mechanism
The proposed mechanism is the family default applied to endocrine tissue: nuclear entry and sequence-selective promoter binding leading to tissue-specific transcriptional change. For Testagen exactly one experiment addresses the first half of that claim and nothing addresses the second. No hormonal measurement of any kind appears in the indexed literature.
Nuclear entry and motif-selective DNA binding
Fluorescein-labelled testagen produced marked fluorescence in the cytoplasm, nucleus and nucleolus of HeLa cells and interacted preferentially with particular deoxyribooligonucleotide motifs, discriminating cytosine methylation, in a study that tested it alongside epitalon and pinealon. This is the sole biological experiment naming Testagen in the indexed literature.
Endocrine and immune claims carry no primary data here
The 2025 corrosion paper summarises Testagen, citing the originating literature, as a bioregulator intended to stimulate endocrine function and capable of directing stem cells toward immune-system lineages. Those are secondary restatements; the underlying experiments are not retrievable in the indexed record and no androgen, gonadotrophin or spermatogenesis endpoint appears anywhere.
Target organ is inconsistent across sources
The manufacturer's distributor network labels Testagen an endocrine-system peptide, a materials-science paper describes it as an endocrine regulator with immune effects, and Western resellers variously market it for the testes, for testosterone support or for the thyroid. The thyroid attribution appears to be drift from Thyreogen, a different family member.
Best-characterised property is not biological
The most rigorous published work on KEDG is electrochemical and computational: adsorption on copper in sodium chloride solution, Freundlich isotherm fit, standard free energy of adsorption near -31 kJ/mol, and around 86% corrosion inhibition efficiency. It is a competent paper about a metal surface, and says nothing about human physiology.
what’s reported
evidence shape
6 sourcesThe composition of the cited literature by study type. This describes the shape of the evidence, not its quality — and it does not by itself set the grade.
⚠ the catch
Testagen is sold for testosterone and has never been shown to affect a hormone. Only two PubMed-indexed papers name it: one 2011 experiment in which fluorescently labelled KEDG entered HeLa cell nuclei and bound selected DNA motifs, and a 2025 Molecules paper testing it as a copper corrosion inhibitor in saline, which is the more methodologically rigorous of the two and is not about biology at all. There are zero registered studies of the peptide; the record a registry search surfaces belongs to Testagen TDS-Testosterone, an unrelated topical testosterone product, and that name collision is the source of much of the compound's apparent credibility. The sequence is genuinely confirmed as H-Lys-Glu-Asp-Gly-OH, but PubChem attaches no Testagen synonym and no CAS number to it, so CAS is reported null. The one claim of raised serum testosterone traces to a small Ukrainian-language report that could not be retrieved or verified.
key published findings
- The sequence is confirmed as H-Lys-Glu-Asp-Gly-OH (KEDG) in both indexed papers, with C17H29N5O9 and 447.4 from PubChem CID 123863700; no CAS number and no Testagen synonym exist in that record, so CAS is reported null.
- The commonly circulated claim that Lys-Glu-Asp-Gly is Pancragen is wrong: KEDG is Testagen, and Pancragen is the tryptophan amide Lys-Glu-Asp-Trp-NH2.
- Only two PubMed-indexed publications name Testagen, and the more recent and more rigorous of them is a copper corrosion-inhibition study reporting around 86% inhibition efficiency in sodium chloride solution.
- The single biological experiment showed FITC-labelled testagen reaching the nucleus and nucleolus of HeLa cells and binding selected DNA motifs, tested together with epitalon and pinealon.
- ClinicalTrials.gov holds zero registered studies of the peptide; a query for 'Testagen' instead returns a skin-transference pharmacokinetic study of Testagen TDS-Testosterone, an unrelated topical testosterone product.
- No published study measures testosterone, gonadotrophins, spermatogenesis or any endocrine endpoint after Testagen administration.
limitations of the evidence
- Zero human studies of the peptide, zero registered trials, and zero hormonal measurements of any kind.
- A single biological experiment in an immortalised cancer cell line underpins the whole mechanistic claim.
- The name collides with an investigational topical testosterone product, so registry and literature searches produce false reassurance for buyers.
- Target organ is inconsistently stated across the manufacturer's distributors, the secondary literature and resellers, with thyroid claims apparently drifting in from Thyreogen.
- The one androgen-raising human claim in circulation rests on a small report in a Ukrainian endocrinology journal that could not be retrieved, so it is treated here as unverified.
- Sources overlap with the other Khavinson bioregulators in this index because these compounds are described in one shared body of literature; shared reviews are not independent support for testagen.
documented safety signals
- No toxicology, human safety data or adverse-event surveillance of any kind were located for the peptide.
- Absence of reported harm reflects absence of monitored human exposure rather than demonstrated safety.
- The name collision with a testosterone product creates a real-world risk of misattributed expectations and, for tested athletes, of confusion with a substance class that is prohibited in sport.
identity
| full name | Testagen (Lys-Glu-Asp-Gly; KEDG tetrapeptide) |
| category | Ancillary & Endocrine |
| modality | peptide |
| formula | C17H29N5O9 |
| molar mass | 447.4 g/mol |
| sequence | Lys-Glu-Asp-Gly (KEDG) |
laboratory handling
| storage | Lyophilised powder is stored desiccated at -20 °C and protected from light. Once reconstituted, laboratory practice is refrigeration at 2-8 °C for short-term use, or aliquoting and freezing to avoid repeated freeze-thaw cycles. Handling information only; this material has no approved human use. |
| solubility | Short hydrophilic peptide, readily soluble in sterile or bacteriostatic water and in dilute aqueous buffer. Lot-specific solubility is stated on the certificate of analysis. |
Handling information describes laboratory practice for a research reagent. It is not a preparation guide for use in humans.
the receipts
6 citedPubChem, NCBI · 2026 · official
ClinicalTrials.gov, US National Library of Medicine · 2026 · official
ClinicalTrials.gov, US National Library of Medicine · 2016 · official
Biochemistry (Moscow) · 2011 · preclinical
Molecules · 2025 · preclinical
Molecules · 2021 · systematic review
others in Ancillary & Endocrine