Carl read the papersWhat it actually is
Testagen is a synthetic tetrapeptide, Lys-Glu-Asp-Gly (KEDG), from Khavinson's short-peptide programme in St Petersburg. In Russia an oral capsule version is registered as a dietary supplement listing 100 mcg of a peptide complex per capsule, filed under male infertility and male menopause.
Online it is marketed as a testes bioregulator that supports natural testosterone. The developers' own reviews call it a regulator of the male reproductive system. The trouble is what that claim rests on, which is covered below.
How it’s thought to work
- Into the nucleus — Fluorescent-labelled Testagen got into the nucleus of HeLa cells and bound DNA in vitro, preferring CAG-containing sequences.
- Histone binding — Binds histone proteins in vitro, the family's proposed route to switching genes on and off.
- Pituitary-thyroid axis (in birds) — Described as an anterior-pituitary peptide in chick studies, where it helped restore thyroid hormones and thymus structure after the pituitary was removed.
- Testes and testosterone — Claimed, not shown. We found no study measuring testosterone, LH, FSH or sperm after Testagen.
What the research says
Close to none for what it is sold for. The developers' 2021 systematic review lists KEDG as Testagen, a male reproductive regulator, and backs that with three references: a histone-binding paper, a cell-differentiation review and a mouse-heart gene study. None of them looks at testes. A 2022 review from the same group repeats the label with no reference at all. The animal work on this exact sequence is in chickens with their pituitary removed, where it was described as an anterior pituitary peptide and helped restore thyroid function and thymus structure. The newest PubMed paper on Testagen tests it as a copper corrosion inhibitor in salt water (about 86% efficient, for the record). No human trial is registered.
- Khavinson-family tetrapeptide (KEDG); Russian oral supplement at 100 mcg per capsule.
- Marketed for testosterone and male fertility; no published study measures either.
- Published work: nuclear entry and DNA/histone binding in vitro, thyroid and thymus effects in chickens without a pituitary.
- The name is also used by an unrelated testosterone spray (Testagen TDS) in a registered trial. Different product.
Reported protocols
These are the doses the peptide community actually reports running (Reddit & forums), alongside published research — logged for education, not as a recommendation to use.
| Parameter | Commonly reported range |
|---|---|
| Community dose | Not established. We found no vendor-independent user reports; the 'protocols' we found came from sellers or affiliate channels. |
| Russian label (oral) | 100 mcg peptide per capsule, 1 to 2 capsules, 1 to 2 times a day with food for one month, repeat after 4 to 6 months. A supplement label, not a tested dose. |
| Injectable | No published human or animal dose for any testes or testosterone outcome. |
| Carl's note | One milligram is ten of the Russian capsules. Milligram-level injectable protocols are not anchored to any study. |
Common use cases
| Goal | Community protocol notes |
|---|---|
| Natural testosterone support | the marketed use; no published evidence |
| Male fertility | the Russian label's filing (male infertility and male menopause codes); no study found |
| Alongside other bioregulators | sold in the same family sets as Epithalon and Prostamax |
Mixing it (reconstitution)
Freeze-dried peptides must be reconstituted with bacteriostatic water before they can be measured. Carl’s calculator turns “mg in the vial + ml of water + target dose” into “units on the syringe” — and tells you how long the vial lasts.
→ Open the Reconstitution Calculator
Injection & handling
No injectable dose has been established for Testagen, and no study has looked at it in testes. The Russian product is an oral capsule. The bird studies used injections, but they were asking a pituitary and thyroid question, not a testosterone one. If someone runs research powder anyway, standard vial hygiene applies. If the real worry is low testosterone or fertility, a morning blood test and a doctor will tell you more than a vial will.
Stacks it appears in
- With HCG or gonadorelin — Often mentioned in the same breath. Those have actual hormone data and both are named on WADA's list. Testagen has no hormone data, so it is not a substitute.
- With Prostamax — Sold together as the 'male' bioregulator pair. Testagen has no testes data at all; Prostamax's prostate data sits in a patent, not a journal.
Sources
- Fedoreyeva et al. 2011, Penetration of short fluorescence-labelled peptides into the nucleus in HeLa cells
- Fedoreyeva et al. 2013, Short peptides binding FITC-labelled wheat histones
- Khavinson et al. 2021, Peptide regulation of gene expression: a systematic review (Molecules)
- Khavinson et al. 2022, Transport of biologically active ultrashort peptides using POT and LAT carriers (Int J Mol Sci)
- Khavinson et al. 2020, Peptide regulation of cell differentiation (review)
- Anisimov et al. 2002, Vilon and Epithalon effects on gene expression in mouse heart
- Kuznik et al. 2008, KEDG and AEDG on the thyroid in neonatally hypophysectomised chickens
- Kuznik et al. 2011, KEDG and AEDG on thyroid in hypophysectomised chickens and old hens
- Pateyk et al. 2013, KEDG and AEDG on thymus morphology in hypophysectomised birds
- Dobritescu et al. 2025, Testagen peptide as a copper corrosion inhibitor in saline (Molecules)
- Khavinson et al. 2023, Transport of 26 ultrashort peptides via LAT and PEPT transporters (Biomolecules)
- RLS (rlsnet.ru) registry: Testagen, dietary supplement (BAD)
- ClinicalTrials.gov NCT02733133: Testagen TDS testosterone 5% spray (unrelated product)
- SAHPRA, Peptide Products: Public Information (May 2026)
- WADA Prohibited List 2026 (S0 and S2.2.1)
