PE-22-28 (Mini-Spadin)
What it’s used for
PE-22-28, also called Mini-Spadin, is a seven-amino-acid peptide shortened from spadin. It blocks TREK-1, a channel that affects how excitable nerve cells are. People use it for depression, anxiety, memory and brain protection, most often as a nasal spray at 200–400 mcg each morning. Evidence is limited to cells and mice; there are no human trials.
- Depression & mood Lab & animal research Reduced depression-like behavior in mice, with effects seen within four days.
- Anxiety Lab & animal research Explored for anxiety and new nerve-cell growth in animal models.
- Memory & brain protection Community reports Explored for memory and protection after stroke; these uses are still ideas, not tested results.
Side effects & safety
Side effects
No side effects documented yet.
Stop and get help if
- Agitation, confusion, racing heart, high blood pressure or twitching — possible signs of serotonin toxicity
- Seizures or chest pain
- Signs of an allergic reaction
- Mania or suicidal thoughts
- Unusual bleeding
- Nosebleeds, nasal irritation or infection that doesn't go away
Which symptoms mean call 911 or see a doctor
Avoid or check first if
- Taking MAOIs — the combination could cause serotonin toxicity in theory
- Taking SSRIs — there's a theoretical risk of too much serotonin
- Taking potassium-channel drugs — they may interact at the same channels
In sport
Likely banned at all times. An early-stage research compound never approved anywhere, so it’s an S0 substance.
Which peptides are banned in sport
How much people take
Injectable
Injectable
For every goal: Once daily · under the skin
- Research protocol (human equivalent - theoretical) 50–100 mcg
- Research protocol (conservative) 100–200 mcg
Similar doses appear in 2 other sources
Nasal
For every goal: Nasal spray
- Depression & mood Once daily, in the morning · 4–8 weeks on, then a break 200–400 mcg
- Research protocol (theoretical) Once or twice daily 100–300 mcg
Similar doses appear in 3 other sources
How to mix and store it
How many units do I draw?
Injectable
Open the full calculator
Injectable
How to mix 5 steps with bacteriostatic water · vial check
How to mix
- 1 Wipe both tops Wash your hands, then swab the rubber tops of the peptide vial and the water vial with alcohol. Let them dry.
- 2 Draw the water Use bacteriostatic (BAC) water — sterile water with a preservative, sold for mixing peptides . With a new sterile syringe, draw the amount you entered in the calculator. A 1 mL syringe filled twice is 2 mL.
- 3 Run it down the wall Push the needle into the peptide vial at an angle and let the liquid trickle down the glass, not onto the powder.
- 4 Swirl, don’t shake Gently swirl or roll the vial until the liquid is completely clear. Give it a few minutes if needed.
- 5 Label the vial Write the date and what you mixed (for example 5 mg + 2 mL) on the vial.
This is general practice. If your product came with its own diluent or instructions, follow those. Not sure what to buy? See the supplies checklist .
Is my vial OK?
Good signs
- White freeze-dried powder
- Clear, colorless mixed solution
Don’t use if
- Cloudy, discolored, or particles visible
- Clumped or sticky powder
Injecting under the skin Where, rotating sites, which syringe
- Where: belly (at least 2 in / 5 cm from the navel), front of the thigh, or back of the upper arm.
- Rotate sites each time and skip bruised, scarred or sore skin.
- Syringe: most people use a U-100 insulin syringe with a short, thin needle (29–31 gauge, 8 mm or shorter).
- How: wipe with alcohol and let it dry, pinch the skin, go in at 45–90°, push slowly. Use each syringe once.
General practice for under-the-skin injections, not specific to PE-22-28 (Mini-Spadin).
The full guide: how to inject safely
Storage
Fridge · 4–6 weeks Reported shelf life, not lab-tested. Mixed vial refrigerated, use within 4–6 weeks. Dry powder at 2–8°C (35.6–46.4°F), or -20°C (-4°F) long term
Nasal
How to mix 5 steps with bacteriostatic water
How to mix
- 1 Wipe both tops Wash your hands, then swab the rubber tops of the peptide vial and the water vial with alcohol. Let them dry.
- 2 Draw the water Use bacteriostatic (BAC) water — sterile water with a preservative, sold for mixing peptides . With a new sterile syringe, draw the amount your product calls for. A 1 mL syringe filled twice is 2 mL.
- 3 Run it down the wall Push the needle into the peptide vial at an angle and let the liquid trickle down the glass, not onto the powder.
- 4 Swirl, don’t shake Gently swirl or roll the vial until the liquid is completely clear. Give it a few minutes if needed.
- 5 Label the vial Write the date and what you mixed (for example 5 mg + 2 mL) on the vial.
This is general practice. If your product came with its own diluent or instructions, follow those. Not sure what to buy? See the supplies checklist .
Storage
Fridge once mixed
Combining it with others
AI assessment Based on how each compound works, not on studies of the combination. How we assess
Use caution 1
- Antidepressants (SSRIs, SNRIs) Both act on serotonin signaling. Start low and watch for agitation.
Can be combined 8
Semax NA Semax Amidate Adamax Selank Adalank Dihexa P21 Bromantane
What the research says
Mostly animal studies
- Human dosing, effects and side effects are unknown, and human half-life is unknown.
- The injected doses listed are theoretical conversions from mouse studies; the nasal dose comes from community guides.
- Absorption by mouth or nose in people is unknown; oral activity was seen in animals, and nasal use rests on community reports.
- There's no tested timeline in people, especially for oral or nasal use.
- Heart-safety findings in animals don't show it's safe for the human heart.
- Activity-duration figures come from modified versions of the peptide, not human measurements of PE-22-28.
- Interactions haven't been studied in people; stack ratings come from a reference source and aren't proof of safety.
What studies found
- Channel and mouse-behavior evidence The seven-residue peptide blocked TREK-1 in cells and reduced depression-like behavior in mouse assays. This does not show that it treats depression in people.
A half-life hasn’t been verified for this compound.
What it’s made of
- Length
- 7 amino acids
- Molecular weight
- 773.89 Da
- Formula
- Not verified
Sequence 7 · N → C
- G
- V
- S
- W
- G
- L
- R
Identity as reported in peptide guides; exact-product sequence and modifications have not been independently confirmed.
Distinguish PE 22–28 from G/A and biotinylated derivatives.
Length and weight come from a reference listing and were not independently confirmed.
Doses in animal and lab studies 3
Doses used in animal or cell studies. They don’t translate directly to people.
- Preclinical antidepressant studies (mouse) 3–4 mcg/kg · Once daily · IP
- Preclinical oral studies (mouse) 1 mg/kg · Once daily · Oral gavage
- Preclinical oral study (mouse) 1 mg/kg · Once daily · Oral gavage
Sources
Sources 14
How this page was made
How it may work: TREK-1 blockade alters neuronal excitability, serotonin signaling and downstream plasticity.
Preparation in studies: No product-specific preparation or stability instruction was verified.
Animal cardiac selectivity does not establish human cardiac safety; combination labels are source claims.
Research last checked: Oct 12, 2026 (a targeted search, not a full review).
Community doses, how long people take it, timing and storage are compiled with AI from public peptide guides, clinics and forums, cross-checked against other sources where we could, and rewritten in plain language. “Combining it with others” is an AI assessment of how the compounds work. Study notes are written from each paper’s abstract where one exists. How we source
Original source guide