Bioregulators Khavinson bioregulator tetrapeptideNot FDA-approved · research compound

Testagen

Testagen (Khavinson)

Evidence: Studied in humans. Example dose: finalize with a provider. Not a fact-check stamp.

100 mcg daily SubQ 8-16 week course

10-20 mg Oral Daily

Testicular tissue regulatorGene expression modulator

Testagen (Lys-Glu-Asp-Gly) is a Khavinson bioregulator tetrapeptide targeting testicular tissue gene expression. It supports Leydig cell function, Sertoli cell maintenance, and testicular hormone production pathways. Complementary to HCG (direct LH receptor stimulation) for comprehensive testicular support during TRT.

Quick Start

Route

SubQ injection

Start low

100 mcg SubQ

Frequency

8-16 week course

Timing

No fasting required

Starting dose. 100 mcg — Daily

SubQ injection, any time of day. 10-20 day courses, 2-3 cycles per year with 4-6 months between courses (Khavinson protocol). Pin alone or with other bioregulators only.

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Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.

Tiered Protocols · lowest first

Conservative start

100 mcg daily · SubQ injection · 8-16 week course

conservative starter

100 mcg daily

8-16 week course

Standard

Testicular Bioregulation (Oral capsule)

10-20 mg · Oral · Daily

animal study · Khavinson et al., Advances in Gerontology, 2010

Does not replace testosterone, but rather attempts to rejuvenate the Leydig cells to restore endogenous production. Human use has been published, but almost entirely by a single research group in Russian-language journals. None of it is registered on any trial registry and most reports were unblinded, so this evidence is far weaker than a controlled trial. This is the ORAL capsule dose and is not an injection dose. Oral peptide absorption is poor, so this figure is far higher than the injectable protocol on purpose. Do not inject this amount.

10-20 mg

Daily

Reconstitution CalculatorU-100

Vial strength

BAC water

Vials in this mix

Syringe size

Target dose

050100u

Draw to

— units

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I will split this dose across more than one syringe

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How it works

Testagen modulates gene expression in testicular tissue (Leydig cells, Sertoli cells), supporting steroidogenic enzyme expression, LH receptor sensitivity, and spermatogenic support pathways at the gene level.

What to expect

Early

Days 1–7

Days 1-10: Gene changes initiated.

Mid

Weeks 2–4

Weeks 2-8: Testicular gene programs established.

Later

Weeks 4–12

Months: Sustained testicular tissue support.

Evidence

HumanPresent

AnimalPresent

In-vitroPresent

Claims we could not support

No abstract we checked supports these for this molecule at this route. That is not the same as saying they are false — it marks where the evidence is missing.

Exact-molecule abstract evidence. ESearch was run and 2 source-candidate PMIDs were EFetch-checked; no usable exact-molecule abstract sentence was found.

Dose/route: 100 mcg daily; SubQ injection; 8-16 week course. No selected live abstract sentence verified this complete regimen.

Mechanism as written in source JSON. No selected live abstract sentence verified the complete mechanism at the card formulation/route and relevant population/model.

Primary safety claim as written in source JSON. No selected live abstract sentence verified the complete safety claim for this exact formulation and route.

The honest take

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Testicular rejuvenation

Bioregulatory gene expression modulation targeting testicular tissue. Complementary to direct hormonal stimulation (HCG).

Interactions & stacking

Two different questions: what is documented about running these together, and what is documented about drawing them into the same syringe. A good pharmacological partner can still have to be pinned separately.

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Pin alone. Testagen must not share a syringe with anything else, whatever the pharmacology says. PIN ALONE.

Documented together

HCGTestagen targets testicular gene expression, HCG stimulates Leydig cells directly. Complementary testicular support.

ProstamaxTestagen testicular + Prostamax prostate. Complementary male reproductive support. Run in sequence.

Keep separate

GHK-CuCopper degrades bioregulators.

Check any specific pair in the Stack & Interaction Checker, which answers both questions separately. Absence of a documented conflict is not evidence of safety.

Side effects & safety

Commonly reported

Very well tolerated

Less common & notes

Monitor testosterone and estradiol if on TRT.
Excellent safety profile.

Pharmacokinetics

Illustrative plasma concentration · 2.0 h

Half-life

0.5h

Peak · Tmax

0.05h

Elimination

2.5h

Bioavailability

~100%

SubQ

Duration of action

Weeks to months (epigenetic gene expression changes persist beyond dosing course)

Clearance

Enzymatic degradation (aminopeptidases)

Storage. Standard BAC water 2-8C. 21-28 days.

Regulatory status

Not FDA-approved. Research peptide.

Put it to work

Calculate, log & track

Open Testagen straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.

Open Testagen in the app →

Go deeper

The guide & community

The complete Testagen walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.

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