Side-by-side · Research reference
PE 22-28vsSelank
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
BHuman-MechanisticAUTO-DRAFTED11/40 cited
PE 22-28
TREK-1 Antagonist · Pre-Clinical
IP · SQ · Once Daily (animal models)Djillani 2017Pietri 2019
Selank
Anxiolytic + Cognitive · Russian Pharma
Intranasal · 2–3×/day during stress / cognitive demand
01Mechanism of Action
Parameter
PE 22-28
Selank
Primary target
TREK-1 two-pore-domain potassium channelDjillani 2017Ma 2020
Monoamine system (serotonin / GABA modulation) + immunomodulation via tuftsin domainZaderej 2014
Pathway
TREK-1 channel blockade → Neuronal membrane depolarisation → Enhanced hippocampal excitability → Increased neuroplasticity
Tuftsin-derived immune signaling + CNS monoamine modulation → reduced anxiety + improved mood / cognitionMedvedev 2007
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
Anxiolytic + cognitive enhancement; immunomodulation via increased IL-6 + IFN-γMedvedev 2007Zaderej 2014
Feedback intact?
N/A — direct ion channel blockade; not receptor-mediated endocrine axis
No GABA-receptor binding; no dependence reportedMedvedev 2007
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
Synthetic 7-AA peptide derived from human tuftsin (immune-system tetrapeptide)Zaderej 2014
Antibody development
Not reported in animal studies
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02Dosage Protocols
Parameter
PE 22-28
Selank
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.
2–3× per day during stress
Onset (animal)
Within hours (acute); full effect 4–7 days
—
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
Human-mechanistic + Russian clinical trialsMedvedev 2007
Lower / starter dose
—
75 mcg / dose
Duration
—
10–14 day cycles, repeated as needed
Reconstitution
—
Pre-formulated nasal spray (commercial); research vial: bacteriostatic water
Timing
—
Morning + early afternoon preferred
Half-life
—
Short (minutes plasma); CNS effect lasts ~3 hr
04Side Effects & Safety
Parameter
PE 22-28
Selank
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
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Long-term safety
Unknown — longest animal study 28 days
Limited Western RCT data
Nasal irritation
—
Mild burning or congestion (transient)
Cognitive impairment
—
None — opposite effect (enhancement)
Allergic reaction
—
Rare hypersensitivity
Pregnancy / OB
—
Avoid — insufficient data
Absolute Contraindications
PE 22-28
- ·Human use — no clinical safety data available
Selank
- ·Pregnancy / breastfeeding
- ·Hypersensitivity to peptide
Relative Contraindications
PE 22-28
- ·Cardiac arrhythmia or channelopathy (theoretical TREK-1 cardiac role)
Selank
- ·Active autoimmune disease (theoretical via immunomodulation)
05Administration Protocol
Parameter
PE 22-28
Selank
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.
Pre-formulated nasal spray (commercial) or research vial reconstituted with bacteriostatic water.
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
Intranasal — 1–3 sprays per nostril per dose. Tilt head slightly back.
3. BBB penetration
Enhanced CNS bioavailability vs full spadin, likely due to smaller size. Mechanism (passive diffusion vs active transport) not fully characterized.
Morning + early afternoon for cognitive demand; PRN for acute anxiety.
4. Human formulation
Not established — peptide synthesis methods for research use only. No pharmaceutical-grade formulation available.
Refrigerate after reconstitution; ≤30 days. Light-protected.
5. Caveat
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Avoid co-administration with strong sedatives or other anxiolytics initially.