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Testagen

Khavinson bioregulator

Also: KEDG · Lys-Glu-Asp-Gly · H-Lys-Glu-Asp-Gly-OH · anterior pituitary peptide · peptide complex AKS-S · Тестаген

AvoidLibido & hormonesInjection / Oral

Khavinson's 'testicular' tetrapeptide KEDG; its only in-vivo work is on the thyroid axis in chickens.

Safety tier
Avoid
strict bar
Positive
53%
of 7 reports
Per month
≈ €32–81≈ $36–90
estimate
Rank
#43
of 86 research peptides

At a glance

Onset
Users who felt it describe changes within the first week of daily injections; the one with blood tests saw no change in testosterone.
Lasts
Run as 10-30 day courses, two or three times a year.
Access
Grey market
Strict case
The only in-vivo studies found that KEDG raises thyroid-stimulating hormone and thyroid hormones (in chickens), and it is injected at milligram doses to push the testosterone axis with no human safety data, so an unmeasured endocrine effect cannot be ruled out.
Best effects
Felt stronger in the gym, more libido and night-time erections (confounded by kisspeptin or testosterone) · testosterone up about 150 points (one report, run with Testoluten) · claimed: restores testicular function and fertility (manufacturer)
Downsides
No change in testosterone on blood tests (the only measured report) · no felt effect for some · cost of an injectable with modest returns · usually run with kisspeptin, testosterone or Testoluten, so its share is unknown
Typical use
No established human dose. Users inject 0.5-2 mg a day subcutaneously or intramuscularly for 10-30 days; capsules (0.1 mg each) are taken 1-2 twice a day with meals for a month, repeated after 3-6 months (manufacturer).
Stacked with
Stacked with
Kisspeptin: The most common pairing for men trying to raise testosterone without TRT; the one pair checked on blood tests showed no change. · Testoluten: The Khavinson sequence: the synthetic peptide first, then the testis extract capsules; one report of a 150-point testosterone rise used both. · Vesugen: Promoted together for libido and blood flow by a shop affiliate; no independent reports.

Safety

Watch
In hypophysectomised chickens it raised TSH, T3 and T4 and restored the thyroid (one Russian group): an unmeasured thyroid effect in people is possible · Grey-market injectable vials: purity, sterility and identity unverified
Tier by safety barStrict AvoidBalanced CautionEvidence only Caution
  • Seen harm0 of 3
  • Mechanism2 of 3
  • Data gap3 of 3
  • Silent harm2 of 3
  • Product3 of 3
Never if
Thyroid disease or thyroid medication (the only in-vivo data are thyroid-axis effects) · Men trying to conceive who would put it in place of an assessment of low testosterone or infertility · Prostate cancer or hormone-sensitive cancer (sold to raise testosterone) · Pregnancy or breastfeeding (no human reproductive data)
Why each score
Seen harm 0/3
No serious adverse event has been reported in any study, source or first-hand account, but the zero reflects how little documented human exposure there is (a handful of Reddit and X users, no study in people), not reassurance. r/BodyHackGuide: Testagen or Vilon protocol (user reports, none of harm)
Mechanism 2/3
Hormone-axis activation shown in animals: in a series of in-vivo studies, KEDG (synthesised as the 'anterior pituitary peptide') raised thyroid-stimulating hormone, T3 and T4 and restored the thyroid in hypophysectomised chickens and hens. It is one Russian group, in birds without a pituitary, and nobody has looked in intact mammals or at the gonadal axis users take it for, but the RUBRIC places in-vivo hormone-axis effects at 2. Kuznik et al. 2008: KEDG raised TSH and thyroid hormones in hypophysectomised chickens (PubMed 19024016)Kuznik et al. 2011: KEDG on thyroid hormones in young chickens and old hens (PubMed 22268052)Kuznik et al. 2011: KEDG increased TSH, T3 and T4 in hypophysectomised birds (Adv Gerontol, PubMed 21809626)
Data gap 3/3
Registered nowhere as a drug, and no human safety data for KEDG at all: no trial, case series or even developer clinic report has been published. The in-vivo work is in chickens; the capsule is sold as a Russian food supplement without published studies. Kuznik et al. 2010: KEDG in hypophysectomised chickens (PubMed 20731122)
Silent harm 2/3
The feared harm behind the mechanism score, a change in thyroid (or other pituitary-driven) hormones, would build up silently but would show on a blood test. Kuznik et al. 2008: thyroid-axis effects of KEDG (PubMed 19024016)
Product 3/3
Reddit and X users inject grey-market 20 mg vials subcutaneously or intramuscularly, of unverified purity and sterility; the Khavinson-line capsules (about 0.1 mg per capsule, sold as a supplement) are a lower-risk minority channel. Mendias & Awan 2026 preprint: 6,441 grey-market peptide samples, 42-71% failed quality criteria, 15% had endotoxin

User reports

All 9 reports
Users report
Few reports, and the hormone claim is not borne out where anyone measured it. The one Reddit user who checked his blood before and after Testagen with kisspeptin found no change in testosterone, and another on the same pair felt nothing after two weeks. Four describe something: 'decent results' from 2 mg a day for 20 days, feeling it more when injected intramuscularly than subcutaneously, night-time erections and gym gains (with kisspeptin), and a 150-point testosterone rise (with Testoluten, the testicular extract), so most positives are shared with another product. One former user would not recommend it, and a Brazilian poster calls it his most disappointing peptide for the cost. On X the glowing accounts come from a shop affiliate with a discount code. Felt nothing: 2 of 7 first-hand Reddit reports, including the only one with blood tests.
Positive 4Nothing 2Negative 1
  • r/NTNPerformance

    My research subject ran testagen and testoluten for a cycle and it brought their T levels up about 150 points. I will say they tend to be a fairly strong responder though.

    • 5 points
    Positiveone cycle
  • r/BodyHackGuide

    When I was doing testagen IM I could feeling. I converted to subq and less so but the numbers will tell me

    • 3 points
    PositiveInjection
  • r/BodyHackGuide

    I got bloods done earlier this year as I wanted to *research* Testagen and Kisspeptin to see if they made any difference at all to Test levels (which they didn't).

    • 3 points
    Nothing

Studies

Evidence
Animal only — No human study. The in-vivo work is a series by one Chita group (Kuznik and colleagues) in which KEDG, synthesised as the 'anterior pituitary peptide', restored the thyroid, TSH and thyroid hormones, the thymus, immunity and haemostasis in hypophysectomised chickens and hens. The rest is cell-penetration and DNA- and histone-binding chemistry. No study in any species has measured testosterone, sperm or testicular tissue.
Caveat
Nothing ties KEDG to the testes except the product name: no study in any species has measured testosterone, sperm or testicular tissue, and the published in-vivo work treats it as a pituitary peptide acting on the thyroid. Those chicken studies are the reason for the Avoid verdict, a hormone effect seen in animals by one group and never checked in people; the vials are injected at up to ten times the capsule dose with no rationale.
3 more studies and 4 sources

Sources

Similar peptides

Research notes, not medical advice. Updated . Also as Markdown.

Sequence

The peptide's chain of amino acids from its start (the N-terminus) to its end, one bead and one letter for each: A alanine, C cysteine, D aspartic acid, E glutamic acid, F phenylalanine, G glycine, H histidine, I isoleucine, K lysine, L leucine, M methionine, N asparagine, P proline, Q glutamine, R arginine, S serine, T threonine, V valine, W tryptophan, Y tyrosine. A modification such as an N-acetyl cap or a C-terminal amide changes how long it lasts in the body. Length tells related peptides apart, from a two-residue dipeptide like carnosine to a 43-residue protein like thymosin beta-4, and predicts neither effect nor safety.

Report grades

Every first-hand Reddit or X report is graded on its own, from glowing through positive, mixed, nothing and negative to bad reaction, and the bar shows how those grades split. Posts that look vendor-adjacent stay on the peptide's page but are left out of the counts.

GlowingPositiveMixedNothingNegativeBad reaction

% positive

The share of a peptide's graded Reddit and X reports that are glowing or positive, vendor-adjacent posts left out. A peptide with few reports is pulled toward the average of all reports, as if it had eight average ones besides its own, so two glowing posts cannot top the list. Peptides rank by this figure, those with no graded report yet after those with one, and Avoid ones after every other entry.

Researcher estimate

No first-hand report of this peptide has been graded yet, so the figure is the researchers' own rating out of 10 from what they read about it. It ranks after every peptide with graded reports until its own arrive.

Safety tier

Each peptide is tiered Clean, Caution or Avoid from its five risk axes under the chosen safety bar. An Avoid peptide carries a real risk of harm, a plausible route to serious harm rather than mere unpleasantness, so it stays listed with the reason but ranks behind every other entry, however good its reviews.

Safety bar

The safety bar sets how much risk it takes to rate a peptide Avoid. Strict: out on any serious mechanism with little human data, or any documented serious harm. Balanced: out on documented serious harm (unless it is obvious, reversible and from a regulated product), or a serious mechanism whose harm would be silent with no human data at all. Evidence only: out only on documented serious harm in humans that is lasting, delayed or from grey-market product.

Seen harm

Documented serious adverse events in humans, from 0 for none despite real exposure to 3 for deaths or several well-documented serious harms. Serious means a hospital or emergency visit or harm lasting weeks, so a headache or a bad night does not count.

Mechanism

A plausible biological route to serious harm at the doses people use, such as growth-factor signalling, hormone-axis suppression, heart or blood-pressure effects or immune activation. It runs from 0 when none is known to 3 when a dangerous pathway has been shown in living animals.

Data gap

How little human safety data exists for the molecule actually sold, from 0 for an approved drug with large trials and years of use to 3 for no human safety data at all. A modified analogue does not inherit its parent's trials.

Silent harm

Whether the feared harm would show quickly or stay hidden, from 0 when it is obvious and goes on stopping to 3 when it is silent and delayed, like tumour promotion or slow organ damage. User reports cannot reveal a harm that takes years to appear, so a high score here limits what good reviews can tell you.

Product

The risk of what people actually buy, from 0 for a regulated pharmacy or supplement product taken by mouth or on the skin to 3 for a grey-market injectable. In one dataset of 6,441 grey-market samples, 42–71% failed basic quality criteria and 15% carried endotoxin; taken by mouth or in the nose, a pack avoids the injection risks.

Evidence

The strongest kind of study behind the peptide's effects, from an approved drug through human controlled trials and small human studies to animal work or nothing of its own. Animal results often fail to carry over to people.

Access

How people get it: as an approved drug, a compounded prescription, an over-the-counter supplement or from the grey market, where nobody checks the vial. The channel decides both the legal position and the risk of a bad batch.

Price per month

Thirty days of the typical dose, from its low end to its high end, priced at the listing a careful buyer would choose: in stock, from a shop scoring 4 of 5 on trust (third-party tested where no score is set), failing that 3, a pure pack before a blend, a European shop first, then the cheapest per mg. The range is the dose's, not the shops'. A per-dose amount counts once a day unless the dose says otherwise. The shop table keeps each listing's price per mg, per gram for bulk supplements. Where no listing can be priced the researchers' own estimate stands in, and says so.

Dose users report

The middle half of the daily doses stated in at least five first-hand reports, vendor posts left out. Where its middle sits more than twice above or below the declared dose, the month is priced at it as well, since what people take is what they pay for.

Shop trust

Each shop's trust on a 1–5 scale, read from its testing and its reputation: 1 for serious red flags (fabricated COAs, scam reports, impersonation, a closed shop), 2 for no public testing, a new shop or active complaints such as seized parcels, 3 for its own COAs or a short track record, 4 for verified third-party testing or a strong reputation, and 5 for third-party batch reports that name the shop, with years of good independent reputation. A shop without a score counts third-party batch testing as 4, its own COAs as 3 and no public tests as 2.

Best value

Within a category or a goal, a peptide that no other beats on both counts: none is rated more positively for the same or a lower monthly price, and none costs less for the same or a higher rating. The chart joins these into the best-value line; the cheapest of them and the best-rated of them both make it, so the line spans the trade-off from cheap to best. Avoid entries never count, and a peptide needs both a % positive and a price to be compared.

Testing

Whether the shop publishes lab results: third-party tested means an independent lab checks each batch, own COA means the shop's own certificate of analysis, and no public tests means neither. A certificate shows purity, not safety.

Added peptide

Some packs sold under one peptide's name hold a second one, such as 5 mg GHK-Cu in a nasal kit, stated only in the description. Sprayed in the nose or injected it reaches the blood like an injection, so it carries the risk of that route and is tiered as the injectable form, whatever its tier on the skin. A pack whose page gives no contents list may hold more than its name.