# Testagen

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

- Page: https://peprank.xyz/peptides/testagen
- Goals: Libido & hormones (Research peptide)
- Also known as: KEDG; Lys-Glu-Asp-Gly; H-Lys-Glu-Asp-Gly-OH; anterior pituitary peptide; peptide complex AKS-S; Тестаген
- Routes: Injection / Oral
- Safety tier: Strict: Avoid · Balanced: Caution · Evidence only: Caution
- Risk axes (0 none to 3 severe): Seen harm 0, Mechanism 2, Data gap 3, Silent harm 2, Product 3
- Positive: 53% of 7 graded reports glowing or positive, shrunk toward the 49% all-report average by 8 reports' weight
- Rank: #43 of 86 research peptides
- Graded reports: 7 (Positive 4, Nothing 2, Negative 1)
- 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.
- Access: Grey market
- 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.
- Cost per month: ≈ €32–81 (researchers' estimate)
- Updated: 2026-10-30

**Why Avoid under the strict bar:** 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.

## What 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.

**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

**Risks:** 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

**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.

**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).

**Getting it:** Mostly bought as 20 mg research vials of KEDG for subcutaneous or intramuscular injection; the Khavinson-line Cytogen capsules (peptide complex AKS-S) hold about 0.1 mg per capsule and are sold as a Russian food supplement. Testoluten is a different product, a calf testis extract (Cytomax A-13). In the published literature the same tetrapeptide is the 'anterior pituitary peptide', not a testicular one.

**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.)

## Risk profile

- **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.
- **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.
- **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.
- **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.
- **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.
- **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)

## Top reports

- Positive, libido-hormones: “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.” — [r/NTNPerformance](https://www.reddit.com/r/NTNPerformance/comments/1v3ldcb/bioregulators_explained_the_russian_short/oz5juh9/)
- Positive, libido-hormones: “When I was doing testagen IM I could feeling. I converted to subq and less so but the numbers will tell me” — [r/BodyHackGuide](https://www.reddit.com/r/BodyHackGuide/comments/1pslc2o/testagen_or_vilon_protocol/nwesmil/)
- Positive, libido-hormones, 2 mg a day: “I did Testagen 2 mg per day for 20 days. Decent results” — [r/BodyHackGuide](https://www.reddit.com/r/BodyHackGuide/comments/1pslc2o/testagen_or_vilon_protocol/nviddav/)
- Positive, libido-hormones: “Not got bloods tested but running testagen and kisspin 10 gave me bonners at night and gains in the gym . I’m 54m I felt like a had lots more test in me” — [r/BodyHackGuide](https://www.reddit.com/r/BodyHackGuide/comments/1t1k4r5/increase_testo_with_bioregulators/ojhbjqq/)
- Nothing, libido-hormones: “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).” — [r/BodyHackGuide](https://www.reddit.com/r/BodyHackGuide/comments/1va6zum/high_shbg_lowish_free_test_how_to_increase_free/)

## Studies

- [Kuznik, Pateyuk & Rusaeva 2008: Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on the thyroid in neonatally hypophysectomised chickens](https://pubmed.ncbi.nlm.nih.gov/19024016/) (animal, 2008): Given for 40 days to chicks whose pituitary had been removed, the tetrapeptide raised thyrotropic hormone and thyroid hormones and restored thyroid structure.
- [Kuznik et al. 2011: Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on hormonal activity and structure of the thyroid in hypophysectomised young chickens and old hens](https://pubmed.ncbi.nlm.nih.gov/22268052/) (animal, 2011): Both peptides reduced the hormonal and structural thyroid damage after hypophysectomy over 40 days; the normalisation of TSH and thyroid hormones was weaker in old hens.
- [Kuznik et al. 2010: Hypophyseal peptides on immunity, haemostasis and the thyroid in hypophysectomised chickens (Russian)](https://pubmed.ncbi.nlm.nih.gov/20731122/) (animal, 2010): The anterior-pituitary peptide (KEDG) prevented thyroid atrophy and normalised immune and clotting parameters after hypophysectomy.
- [Pateyk et al. 2013: Lys-Glu-Asp-Gly and Ala-Glu-Asp-Gly on thymus morphology in hypophysectomised young and old birds](https://pubmed.ncbi.nlm.nih.gov/23658898/) (animal, 2013): KEDG restored thymic structure after hypophysectomy more than the posterior-pituitary peptide AEDG (Epitalon).
- [Fedoreyeva et al. 2011: Short fluorescence-labelled peptides enter the nucleus of HeLa cells and bind DNA](https://pubmed.ncbi.nlm.nih.gov/22117547/) (in-vitro, 2011): Labelled Testagen (Lys-Glu-Asp-Gly), Epitalon and Pinealon reached the cytoplasm, nucleus and nucleolus of HeLa cells; Testagen bound preferentially to CAG-containing DNA sequences.
- [Fedoreyeva et al. 2013: Short peptides bind FITC-labelled wheat histones](https://pubmed.ncbi.nlm.nih.gov/23581987/) (in-vitro, 2013): KEDG was among six Khavinson peptides that bound histone tails in a site-specific way, offered as an epigenetic mechanism.

## Sources

- [Fedoreyeva et al. 2011: Testagen named as Lys-Glu-Asp-Gly (Biochemistry Moscow, PubMed 22117547)](https://pubmed.ncbi.nlm.nih.gov/22117547/)
- [RuPills: Testagen capsules, peptide complex AKS-S 100 mcg per capsule (manufacturer leaflet)](https://rupills.com/p/testagen-60-capsules-ab8a/)
- [e-peptide: Testagen Cytogen capsules (claims and dosing)](https://e-peptide.com/cytogens/testagen-detail)
- [r/BodyHackGuide: Testagen or Vilon protocol](https://www.reddit.com/r/BodyHackGuide/comments/1pslc2o/testagen_or_vilon_protocol/)