Cognitive & neuroPeptideEvidence C2 cited

PE-22-28

Spadin Analog Nootropic

aka Spadin · PE 22-28 · TREK-1 blocker

A TREK-1 channel blocker researched for rapid antidepressant and pro-cognitive effects in animal models.

Molecular wt
773.9g/mol
Formula
C35H55N11O9
CAS
1801959-12-5
Half-life
2 h
estimated
Tmax
1 h
Route
Subcutaneous injection

Sequence

One-letter7 residues

GVSWGLR

Three-letter

Gly-Val-Ser-Trp-Gly-Leu-Arg

Read this before quoting the sequence
Seven-residue peptide corresponding to residues 22-28 of the sortilin/neurotensin receptor 3 propeptide. It is a shortened analogue of spadin (PE 12-28, a 17-residue peptide) and was designed from spadin's blood degradation products. Linear, free C-terminal acid. Sequence read from the PubChem systematic name 'L-Arginine, glycyl-L-valyl-L-seryl-L-tryptophylglycyl-L-leucyl-'.
Source ↗

Mechanism of action

PE-22-28 works by blocking the TREK-1 potassium channels, which are involved in regulating neuronal excitability and mood. By inhibiting these channels, PE-22-28 may enhance neurotransmitter release, particularly serotonin, leading to rapid antidepressant effects. This action can also improve cognitive function by modulating synaptic plasticity.

What the evidence actually shows

Grade C

There are currently no published human clinical trials for PE-22-28. Existing evidence is primarily from animal studies, which suggest rapid antidepressant and cognitive-enhancing effects. Human trials are needed to confirm efficacy and safety.

Regulatory status

Status
Not approved anywhere. No marketing authorisation and no identified clinical trial.
Clinical stage
Preclinical. No human study of PE-22-28 or spadin was identified in PubMed/Europe PMC searches; all efficacy data are from mice.
UK
research_compound

PE-22-28 is not approved for medical use in the UK and is considered a research compound.

Source ↗

Pharmacokinetics

Half-life
2 h
Tmax
1 h
Absorption
subcutaneous
Elimination
renal
Washout
2 days
Low-confidence pharmacokinetics
These figures are recorded as estimated rather than measured in a published PK study. Treat them as an order of magnitude. Anything downstream of them — accumulation, steady state, washout — inherits that uncertainty.

Dosing — what backs each figure

PE-22-28 is a shortened spadin analogue and a TREK-1 blocker studied only in mice, where 4-day courses of 3-4 ug/kg intraperitoneally (or 1 mg/kg by gavage) produced antidepressant-like behavioural effects. There is no human trial, no human dose and no established route.

PreclinicalAnimal studies — not a human dose
  • PE 22-28 given as 4-day sub-chronic treatment at 3-4 ug/kg (and, in the same figure series, 100 ug/kg) by intraperitoneal injection, or 1.0 mg/kg by oral gavage; assessed in forced swim, novelty-suppressed feeding and learned helplessness tests

    mouse · intraperitoneal and oral gavage · PMID 28955242

Animal doses do not convert to human doses by body weight alone. Route matters too — a compound dosed intraperitoneally in mice tells you little about subcutaneous use.

Commonly circulatedNot established by any study
Dose
200-500 mcg/day
Frequency
Daily

Why this isn't evidence
PE 22-28 has never been administered to a human at any dose, and the mouse work uses weight-based microgram-per-kilogram intraperitoneal dosing or milligram-per-kilogram gavage, neither of which yields a fixed 200-500 mcg/day human figure.

This figure is shown because it is what circulates and what people search for — not because it is supported. Cycle lengths in particular tend to be convention copied between compounds rather than anything derived from a compound's own pharmacokinetics.

No established human dose
No approved label or completed human trial establishes a dosing regimen for this compound. Anything presented as a standard protocol for it — anywhere — is someone's convention rather than a finding.

Handling and storage

No compound-specific stability data exists
No peer-reviewed or regulatory stability data specific to PE-22-28 was located. The published work characterises IN VIVO plasma stability (duration of action up to 23 hours in mice versus about 7 hours for spadin), which is a pharmacokinetic property and not a storage instruction; it must not be presented as shelf life. General peptide handling still applies — reconstitute gently, keep it cold, keep it dark — but any specific figure you see quoted for this compound elsewhere is someone's assumption, not a measurement.

Safety

Commonly reported
  • ·Mild headache
  • ·Nausea
Rarely reported
  • ·Seizures
Contraindications
  • ·Severe liver impairment
  • ·Pregnancy
Drug interactions
  • ·SSRIs: Potential additive serotonergic effects

Reported combinations

Reported as synergistic
  • ·Omega-3 fatty acids
Reported as antagonistic
  • ·Benzodiazepines: May counteract cognitive benefits

Combination claims in this dataset are largely unsourced and should be treated as folk knowledge until a citation appears beside them.

References (2)

Data provenance

Chemistry and citations on this page were checked against primary sources on 2026-08-14. Values that could not be verified were left blank rather than filled with a plausible guess.

Could not verify
storage.lyophilized, storage.reconstituted, storage.lightSensitive, reconstitution.solvent, regulatory.wada

Research use only
This profile is educational reference material. It is not medical advice, not a prescription, and not an endorsement of self-administration. Compounds discussed here are research chemicals and most are not approved for human therapeutic use.