Skip to content
Specimen Atlas of Research Peptides81 plates · MIT
Side-by-side · Research reference

PE 22-28vsTestagen

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AAnimal-StrongHUMAN-REVIEWED16/47 cited
BAnimal-MechanisticHUMAN-REVIEWED11/41 cited
PE 22-28
TREK-1 Antagonist · Pre-Clinical
0.12 nMTREK-1 IC50Djillani 2017
7 AAPeptide lengthDjillani 2017
AnimalEvidence stage
IP · SQ · Once Daily (animal models)Djillani 2017Pietri 2019
Testagen
Bioregulator Peptide · Khavinson School
Lys-Glu-Asp-GlySequenceFedoreyeva 2011
NuclearLocalizationFedoreyeva 2011
TesticularTissue target
SQ · Abdomen · Cyclical

01Mechanism of Action

Parameter
PE 22-28
Testagen
Primary target
TREK-1 two-pore-domain potassium channelDjillani 2017Ma 2020
Testicular tissue; proposed nuclear DNA interaction
Pathway
TREK-1 channel blockade → Neuronal membrane depolarisation → Enhanced hippocampal excitability → Increased neuroplasticity
Nuclear penetration → DNA/oligonucleotide binding → gene expression modulation (bioregulator hypothesis)Fedoreyeva 2011
Downstream effect
Antidepressant-like activity in forced swim test and tail suspension test; reduced A1-like reactive astrocyte activation; neuroprotection via NF-κB pathway modulationDjillani 2017Cong 2023Wu 2021
Proposed support for spermatogenesis and testicular function; mechanistic data limited to nuclear localization and DNA interactionFedoreyeva 2011
Feedback intact?
N/A — direct ion channel blockade; not receptor-mediated endocrine axis
Unknown — no HPG axis data
Origin
Synthetic truncation of spadin (PE 12-28), itself derived from the sortilin propeptide C-terminus. Residues 22-28: Val-Val-Arg-Gly-Trp-Leu-Arg.Djillani 2017Mazella 2018
Khavinson bioregulator school — isolated from testicular tissue peptide fractions
Antibody development
Not reported in animal studies

02Dosage Protocols

Parameter
PE 22-28
Testagen
Animal dose (antidepressant)
0.3–3 µg/kg IP
Effective in forced swim test, tail suspension test, CUMS models.
Animal dose (neuroprotection)
0.03 µg/kg IPPietri 2019
Low-dose TREK-1 activation post-stroke for 7 days, then high-dose blockade.
Frequency
Once daily
Sustained antidepressant effect over 7+ days.
Once daily or alternate days
Onset (animal)
Within hours (acute); full effect 4–7 days
Duration (animal)
7–28 days testedQi 2018Pietri 2019
Comparison to fluoxetine
PE 22-28 outperforms fluoxetine in CUMS-sensitive rats by day 7
Chronic administration shows superior long-term efficacy.
Human equivalent (extrapolated)
Not established — no clinical trials
Allometric scaling from rodent data unavailable.
Evidence basis
Multiple rodent RCTs; behavioral + electrophysiology endpointsDjillani 2017Qi 2018Wu 2021
Animal mechanistic / in vitro onlyFedoreyeva 2011
Typical protocol (anecdotal)
100–200 mcg / day
No published human dosing studies; derived from Russian bioregulator practice.
Cycle length
10–20 days on, 10–14 days off
Bioregulator tradition uses pulsed cycles; no controlled data.
Route
Subcutaneous
Reconstitution
Sterile water or bacteriostatic saline
Half-life
Unknown — likely minutes (short peptide)

04Side Effects & Safety

Parameter
PE 22-28
Testagen
Toxicity (animal)
No adverse effects reported at therapeutic doses
Cardiovascular (theoretical)
TREK-1 expressed in cardiac tissue; arrhythmia risk unclear
Weight change
Not reported in animal studies
Neurological
No seizures or behavioral abnormalities noted
Long-term safety
Unknown — longest animal study 28 days
Unknown — no long-term studies
Injection site reactions
Erythema, mild irritation (potential)
Systemic effects
Unknown — no human safety data
Hormonal impact
No published data on testosterone, LH, FSH effects
Absolute Contraindications
PE 22-28
  • ·Human use — no clinical safety data available
Testagen
  • ·Active testicular malignancy
Relative Contraindications
PE 22-28
  • ·Cardiac arrhythmia or channelopathy (theoretical TREK-1 cardiac role)
Testagen
  • ·Hormone-sensitive cancers (no data; theoretical caution)
  • ·Pregnant or breastfeeding (no data)

05Administration Protocol

Parameter
PE 22-28
Testagen
1. Animal protocol (IP)
Dissolved in sterile saline or vehicle. Intraperitoneal injection, 0.3–3 µg/kg body weight. Once daily administration in rodent behavioral studies.
Add 1–2 mL sterile or bacteriostatic water to lyophilised vial. Swirl gently; do not shake. Solution should be clear.
2. Stability
Shorter peptide length (7 AA) confers improved plasma stability vs 17-AA spadin. Exact storage conditions not detailed in published protocols.Djillani 2017
Subcutaneous — abdomen or thigh. Rotate sites daily. Use standard insulin syringe (27–31G).
3. BBB penetration
Enhanced CNS bioavailability vs full spadin, likely due to smaller size. Mechanism (passive diffusion vs active transport) not fully characterized.
Morning or evening; no established optimal timing. Anecdotal preference: evening to align with circadian testosterone patterns.
4. Human formulation
Not established — peptide synthesis methods for research use only. No pharmaceutical-grade formulation available.
Lyophilised: room temp, dark. Reconstituted: refrigerate 2–8 °C, use within 14–21 days if bacteriostatic water used.
5. Cycle protocol
10–20 days on, 10–14 days off. Bioregulator tradition uses pulsed exposure; rationale: prevent receptor/pathway desensitisation.