Testagen

Lys-Glu-Asp-Gly, KEDG tetrapeptide, "testis bioregulator" (synthetic; not to be confused with Testoluten, a natural testis extract)

Immune & bioregulators

Awaiting medical reviewEN ES DE FR PT ZH+ Follow for updates

Summary

Class: Synthetic tetrapeptide (4 amino acids) from the Khavinson bioregulator family, designed from the amino-acid profile of a testicular extract
Mechanism: Proposed to stimulate cell activity in testicular and pituitary tissue and restore hormone output in ageing males via gene-expression effects; evidence is in vitro and from one group
Routes studied: Organotypic tissue culture; intraperitoneal/subcutaneous injection in rodents (sparse); community: oral and subcutaneous
Dose range reported: Culture: nanogram-per-millilitre concentrations. Animal: µg/kg range in originating-group reports. Community: short courses mirroring the group's 10-day pattern. No validated human dose
Half-life: Not characterised; expected to be minutes, with oral forms likely digested
Storage: Lyophilised: refrigerate, dry, protect from light. Reconstituted: refrigerate, use within ~2–4 weeks (community practice)
Regulatory status: Not approved as a medicine anywhere to our knowledge †

Doses are as reported in studies or by the community — never recommendations.

1What it is

Testagen is a four-amino-acid synthetic peptide (lysine–glutamate–aspartate–glycine) created by the Khavinson group in St Petersburg as the "testes" member of their bioregulator series. It differs from Livagen (profile 75) by a single terminal amino acid, which illustrates how the family was designed: short sequences chosen to match the amino-acid balance of a tissue extract, then assigned a target organ.

The literature on Testagen is among the thinnest of any compound on this site. It appears mainly in organ-culture experiments and in review articles listing the family's claimed tissue specificities. There are no human studies. Online it is marketed, mostly from Russia, for "male hormonal health" and sometimes confused with Testoluten, a natural testis extract sold in capsules under similar branding. The Tier 2 caveat applies in full: one originating group, mostly Russian-language, no independent replication known to us.

2How it's thought to work

Tissue-specific stimulation in culture. in organotypic cultures of rat testis and pituitary, Testagen was reported to increase explant growth and cell proliferation markers, interpreted as organ-specific trophic activity (Khavinson, Chalisova and colleagues).

Gene expression and DNA binding. molecular modelling by the originating group proposes that KEDG, like the other tetrapeptides, can bind particular DNA sequences and shift transcription; also discussed are effects on thyroid tissue and on the pituitary–gonadal axis in reviews.

Hormone output. claims that Testagen raises testosterone in ageing male rats appear in reviews; we have not located a verifiable primary paper with design details.

Proposed: a tetrapeptide directed at testicular tissue, reported in animal work to affect reproductive gene expression. No human trials.Schematic — not to scale

None of this has been tested in humans.

3What the research shows

Organotypic culture of testis and pituitary tissue

Rat tissue explants exposed to Testagen showed increased growth-zone area and proliferation markers relative to control, with the effect reported as more pronounced in tissue from old animals (Chalisova 2003 and related Bull Exp Biol Med papers; Khavinson 2005 monograph). Single group, . [1][2]

Graded C (thin)

Hormonal and reproductive effects in animals

Reviews describe restored testosterone and spermatogenic indices in old or stressed male rats; primary data we can verify are sparse. Treat as "claimed, under-documented".

Thyroid tissue

Some originating-group papers report stimulatory effects of KEDG on thyroid cell cultures, which is one reason the compound is sometimes listed under "endocrine" rather than strictly testicular.

Not gradednone

Human data

No clinical trial, case series or pharmacokinetic study of Testagen in humans has been published in a form we can verify.

4Reported side effects and interactions

Literature-reported

no human safety data; no toxicity reported in rodents.

Community-reported

nothing consistent; most reports are of no effect. Occasional claims of improved libido or energy are indistinguishable from expectation.

Theoretical. if the compound genuinely raised testosterone or stimulated testicular tissue, the standard cautions for anything acting on the gonadal axis would apply (prostate disease, hormone-sensitive conditions, fertility planning); given the absence of any such demonstration in humans, the practical risks are product identity and unverified sourcing.

Interactions. none established. Anyone on testosterone replacement, SERMs, aromatase inhibitors or HCG has no data on how, or whether, this compound would interact.

Markers researchers commonly monitor

No compound-specific markers exist; no human has been shown to respond. Given the claimed target, members who track hormonal protocols would reasonably use:

Marker	Why it's watched
Total and free testosterone, SHBG (morning, fasted, repeated)	the only honest test of the central claim; two baselines before any course, because testosterone varies day to day by more than most compounds move it.
LH and FSH	distinguish a testicular from a pituitary effect if anything changes.
Oestradiol	rises with testosterone; context.
PSA	standard caution for any intervention claimed to raise androgens in men over 40.
TSH, free T4	the originating group also reports thyroid-tissue effects.
CBC and CMP	general baseline for an injected compound with no human safety data.

Free for everyone. Safety information is never behind a paywall.

5Reconstitution and handling

Where sold as an injectable, powder with , swirl gently, refrigerate and protect from light. Capsule products are more common and often contain a testis extract rather than the synthetic KEDG peptide; check the label.

Open in calculator, pre-loaded →

6Commonly studied alongside

Livagen (profile 75), Vilon (profile 74) and Epitalon (set 2) in the originating group's "complex" protocols; in community discussion it is sometimes placed next to kisspeptin-10, gonadorelin and HCG (set 2), which — unlike Testagen — have human data on the gonadal axis.

Informational cross-links. Not stack recommendations.

7Regulatory status by region

Region	Status (checked —)
United States	Not FDA-approved; not known to be on the Category 2 compounding list †
European Union	Not authorised as a medicine or novel food †
United Kingdom	Not licensed
Australia	Not approved
South Africa	Not registered
Sport	Not named by WADA. If it genuinely acted on testosterone it could fall under S2 or S4 depending on mechanism; as a non-approved substance it falls under S0 in any case †

8Open questions

Does a tetrapeptide given orally or by injection survive long enough to reach testicular tissue?
Has any laboratory outside the originating group reproduced the organ-culture findings, or shown any hormonal effect in a living animal?
Whether a single amino-acid change between Livagen (KEDA) and Testagen (KEDG) can plausibly produce organ-specific effects, as claimed.

9References

1Chalisova NI, Khavinson VKh et al. (2003). Tissue-specific effects of short peptides in organotypic cultures of rat tissues. Bull Exp Biol Med [verify exact title and year]. PubMed
2Khavinson VKh, Malinin VV (2005). Gerontological Aspects of Genome Peptide Regulation. Karger, Basel. DOI
3Khavinson VKh, Solovyov AY, Tarnovskaya SI, Lin'kova NS (2013/2014). Mechanism of biological activity of short peptides: cell penetration and epigenetic regulation of gene expression. Biology Bulletin Reviews. PubMed
4Khavinson VKh et al. (2021). Peptide regulation of gene expression: a systematic review. Molecules [verify]. PubMed · DOI

References are being resolved to PubMed/DOI identifiers; links search PubMed for the citation until then.

† Being confirmed by our reviewers against current sources.

10Community

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Self-reported side effects Phase 2

Not enough data yet. 0 of the 50 members needed have logged this compound for 4+ weeks. We don't show anything below 50, so no one can be identified.

11Page history

26 Oct 2026Profile published — awaiting medical review

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