The intranasal-vs-SubQ split, why community reports cap at 600mcg, and the exact syringe math for 10mg and 20mg vials of this un-trialed TREK-1 peptide.
Community PE-22-28 protocols run 200-400 mcg intranasally once daily in the morning, or 100-200 mcg SubQ daily, with self-reports capping total intake under 600 mcg. Those numbers are entirely community-derived: PE-22-28 has never been dosed in a human study.
Research-context information only. PE-22-28 is a research peptide. Protocols, doses, and reactions reported below come from published research and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.
PE-22-28 is a 7-amino-acid spadin fragment that blocks the TREK-1 potassium channel. This guide covers the community protocols, both routes, and the syringe math per vial size.
PE-22-28 Dosing Table
Match your vial size below — reconstitution and dose math update automatically.
Reconstitute: add 2 mL of bacteriostatic water to the 10 mg vial. Resulting concentration: 5 mg/mL.
Daily AM, intranasal (community)Upper end of common reports
100 mcg2 units · 0.02 mL
Daily AM, SubQ (community)
Lower-dose injectable variant
200 mcg4 units · 0.04 mL
Daily AM, intranasal or SubQ (community)
400 mcg8 units · 0.08 mL
Daily AM, intranasal (community)
Upper end of common reports
Math assumes U-100 insulin syringes (1 mL = 100 units). Verify your syringe matches before injecting. Round half-units to the nearest visible mark.
Reconstitute: add 3 mL of bacteriostatic water to the 20 mg vial. Resulting concentration: 6.666666666666667 mg/mL.
Dose
Syringe units
mL volume
Schedule
200 mcg
3 units
0.03 mL
Daily AM (community)
400 mcg
6 units
0.06 mL
Daily AM (community)
200 mcg3 units · 0.03 mL
Daily AM (community)
400 mcg6 units · 0.06 mL
Daily AM (community)
Math assumes U-100 insulin syringes (1 mL = 100 units). Verify your syringe matches before injecting. Round half-units to the nearest visible mark.
Quick Reference: Community Protocol
Note: PE-22-28 has no clinical dosing literature — no Phase 1, no pharmacokinetics, no human safety data. Every value below is a community-reported figure for a compound whose entire efficacy record is mouse behavior.
Parameter
Community Protocol
Dose (intranasal)
200-400 mcg once daily
Dose (SubQ)
100-200 mcg once daily (4 units at 200 mcg, standard dilution)
Timing
Morning
Frequency
Once daily
Cycle
4-8 weeks on, break — general community pattern, not compound-specific evidence
Vial size
10 mg (also sold as 8 mg and 20 mg)
Reconstitution
2 mL bacteriostatic water → 5 mg/mL
Draw amount (200 mcg)
4 units on insulin syringe
Storage
Refrigerate, use within 3-4 weeks per community reports
All figures above are community-reported, not clinical dosing.
Cycling Details
Community reports describe 4-8 week runs followed by breaks. That mirrors the general research-peptide pattern rather than anything PE-22-28-specific: the published animal work used 4-day sub-chronic treatment (Djillani et al., 2017), and no study — animal or otherwise — has examined longer administration.
The reported rationale for the morning-only, sub-600 mcg shape: self-reports describe lethargy at higher doses, so community protocols hold the dose down and keep it early in the day.
Routes of Administration
Intranasal. The most common route in community reports, typically 200-400 mcg once daily from a sprayer after reconstitution. No published human data supports or quantifies nasal absorption for this peptide.
Subcutaneous injection. The lower-dose variant in reports — 100-200 mcg daily. The published mouse work used systemic administration, which is the loose community rationale for the injectable route.
Oral. Not described — as a peptide it would be expected to degrade in digestion, and no oral form or report exists.
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10 mg vial + 2 mL BAC = 5 mg/mL. 200 mcg = 0.04 mL = 4 units. The dilution reflects how community protocols describe the math, not a set of instructions to follow.
Community protocols describe swirling gently rather than shaking, refrigerating at 2-8°C, and using within 3-4 weeks.
Affiliate disclosure: vendor links in this article are affiliate links — The Peptide Catalog may earn a commission if you buy through them, at no additional cost to you.
Where These Numbers Come From
They don't come from trials — that's the honest answer. The only published dosing context is preclinical: the study introducing PE-22-28 demonstrated TREK-1 inhibition at an IC50 of 0.12 nM and antidepressant behavioral effects in mice after 4-day treatment (Djillani et al., 2017), building on the spadin work before it (Mazella et al., 2010).
Community protocols back-form the human figures from vendor sizing and self-experimentation, not from any mouse-to-human scaling published for this compound. The 200-400 mcg range, the morning timing, and the sub-600 mcg ceiling are all convention that hardened through forum repetition. That is worth sitting with before treating the numbers as established.
Stacking Protocols
PE-22-28 appears in community nootropic rotations alongside better-documented peptides:
These are reported combinations with no published interaction data — for an un-trialed compound, stacking adds a second unknown on top of the first.
Side Effects & Safety
No human safety data exists — this is the entire safety profile
Lethargy at higher doses is the most repeated self-report, and the stated reason for the sub-600 mcg community ceiling
Mouse studies reported no cardiac or pain-threshold effects at effective doses — the research group's own selectivity claim, not independently replicated
Nasal irritation reported occasionally with intranasal use
TREK-1 sits in cardiac and pain pathways; the theoretical concern is inherent to the target
mg to Units Conversion
On a standard U-100 insulin syringe, each unit is 0.01 mL. The conversions below reflect the dilutions documented in community protocols — they report how the math is described, not a dosing schedule.
Reconstitution A: 10 mg vial + 2 mL BAC water (5 mg/mL) — the standard dilution from the Quick Reference above.
Dose
Volume (mL)
Units (insulin syringe)
100 mcg
0.02 mL
2 units
200 mcg
0.04 mL
4 units
400 mcg
0.08 mL
8 units
Reconstitution B: 10 mg vial + 5 mL BAC water (2 mg/mL) — more water for larger, easier-to-measure draws.
Dose
Volume (mL)
Units (insulin syringe)
100 mcg
0.05 mL
5 units
200 mcg
0.1 mL
10 units
400 mcg
0.2 mL
20 units
The same math, interactive — pick a vial size and dose to see the exact units to draw and how many doses a vial yields:
Vial size
BAC water added
Dose
Draw (U-100 syringe)
6.0 units
Concentration
5.00 mg/mL
Draw volume
0.060 mL
Doses per vial
33 (~4.8 wk)
U-100 syringe: 100 units = 1 mL. Figures are arithmetic from the vial size, diluent volume and dose entered — presets reflect community-reported and published protocols for research context, not a recommendation. Verify against your own vial label.
What PE-22-28 dose do community protocols describe?
The most widely reported protocol is 200-400 mcg intranasally once daily in the morning. The injectable variant runs lower — 100-200 mcg SubQ daily. Community reports describe staying under 600 mcg total. There is no human trial behind any of these figures; every number is community-derived for a compound tested only in mice.
Is PE-22-28 dosed intranasally or by injection?
Both routes appear in community reports. Intranasal is the more common route in self-reports — the research group's rodent work also used non-injection routes — while subcutaneous injection at lower doses is the alternative. No published pharmacokinetic data compares the routes in humans.
What time of day do reports describe taking PE-22-28?
Morning, consistently — community reports associate it with daytime mood and motivation effects and describe lethargy at higher doses, which is the stated reason for AM dosing and the sub-600 mcg ceiling.
How long is a PE-22-28 cycle in community reports?
Reports commonly describe 4-8 week runs with breaks, mirroring the general research-peptide pattern rather than any compound-specific evidence. The published mouse work used 4-day sub-chronic treatment; nothing longer has been studied even in animals.
How many units is a 200 mcg PE-22-28 dose?
Per documented community reconstitution: a 10 mg vial with 2 mL bacteriostatic water gives 5 mg/mL, so 200 mcg is 0.04 mL — 4 units on a U-100 insulin syringe. With 5 mL of water (2 mg/mL), the same dose is 10 units.
Mazella J, et al. Spadin, a sortilin-derived peptide, targeting rodent TREK-1 channels: a new concept in the antidepressant drug design. PLoS Biol. 2010;8(4):e1000355. PMID 20405001
Djillani A, et al. Shortened spadin analogs display better TREK-1 inhibition, in vivo stability and antidepressant activity. Front Pharmacol. 2017;8:643. PMID 28955242
