Dosage guide · 10 mg vial

PE-22-28 Dosage Protocol

Spadin-derived TREK-1 research heptapeptide

The reference protocol starts at 50 mcg once daily for weeks 1–2, then uses 100 mcg through week 8; 150 mcg and 200 mcg are optional later steps. With 4 mL of bacteriostatic water, a 10 mg vial is 2.5 mg/mL, so 50 mcg is 2 units on a U-100 syringe. No human dose has been established.

How oftenOnce daily

Starting dose50 mcg

Start = units2 units

Mix4 mL BAC water

Reviewed 25 Oct 2026 · Education only, not medical advice

PE-22-28 10 mg vial

View on Peak Peptides

Exact Peak Peptides Australia product photo

Dosage chart How to mix Supplies Calculator About PE-22-28 References

01 · DOSAGE CHART

PE-22-28 dosage chart

Gradual daily reference · 10 mg vial + 4 mL BAC water

BAC water added

Concentration2.5 mg/mL

1 unit (U-100)25 mcg= 0.01 mL

How oftenOnce dailySubcutaneous injection

4 mL gives 2.5 mg/mL, so the 50 mcg reference starting amount is the minimum measurable 2 units on a U-100 syringe.

PE-22-28 dosage chart for a 10 mg vial mixed with 4 mL of bacteriostatic water
Week	Daily dose	Syringe units
Weeks 1–2Start	50 mcg	2 units0.02 mL
Weeks 3–4	100 mcg	4 units0.04 mL
Weeks 5–8Maintenance	100 mcg	4 units0.04 mL
Weeks 9–12	150 mcg	6 units0.06 mL
Weeks 13–16Max	200 mcg	8 units0.08 mL

Once daily · any consistent time · subcutaneous injection

The 150 mcg and 200 mcg steps are optional in the attributed reference protocol.

The reference protocol uses once-daily subcutaneous administration and no evidence-backed clock time.

Reference-site educational amounts only — PE-22-28 has no established human dose or approved medical use. Education only, not medical advice. Dose amounts adapted from PE-22-28 10 mg vial dosage protocol (PeptideDosages.com); units are recalculated for the vial and mix selected above.

02 · HOW TO MIX

Mixing a 10 mg vial with 4 mL of BAC water

Using a 1 mL (100-unit) insulin syringe, 4 full draws of bacteriostatic water gives 2.5 mg/mL.

1
Add the water slowly
Wipe both rubber stoppers with an alcohol swab and let them dry. Draw 4 mL of bacteriostatic water and let it run slowly down the inside of the vial wall — not straight onto the powder.
2
Swirl gently
Swirl or roll the vial gently until the powder has dissolved. Give it a few minutes to settle if needed.
3
Don't shake it
Shaking can damage the peptide and cause foaming. Gentle swirling only.
4
Check it's fully clear
Only use it once it is fully clear with no particles. Label the vial with the date and 2.5 mg/mL, then store it in the fridge at 2–8 °C.

Full illustrated reconstitution guide

03 · SUPPLIES NEEDED

What you'll need

Counts follow the dosage chart above at the highest amount in each step, using a 10 mg vial mixed with 4 mL.

Length of protocol

1PE-22-28 10 mg vial4.9 mg needed in total

571 mL insulin syringesU-100, 27–31G · one per draw + one per vial mixed

1BAC water 10 mL bottle4 mL used for mixing

114Alcohol swabsSkin + stopper, every time

Plus an approved sharps container. Syringes and swabs are sold by Australian pharmacies — Peak Peptides and Pure Performance supply the bacteriostatic water.

PE-22-28 10 mg vialPeak Peptides Australia

Peak Peptides Australia Bacteriostatic water 10 mL

Bacteriostatic water 10 mLPeak Peptides Australia

Pure Performance Australia Bacteriostatic water 10 mL

Bacteriostatic water 10 mLPure Performance Australia

04 · CALCULATOR

Check a different amount

Enter your vial, water and dose to see the matching syringe units.

Concentration Calculator

Labelled Vial Amount (mg)

Verified Final Liquid Volume4 mL

Amount to Evaluate (not a recommendation)

mcg

Concentration

2.50 mg/mL

(2500 mcg/mL)

Calculated Liquid Volume

0.020 mL

Equivalent U-100 volume scale position

2markings (not biological IU)

Illustration of a U-100 volume scale, not preparation or injection guidance

05 · PROTOCOL DETAILS

About PE-22-28

Protocol overview

Starting amount: 50 mcg once daily for weeks 1–2
How it increases: 100 mcg in weeks 3–8; optional 150 mcg in weeks 9–12 and 200 mcg in weeks 13–16
Frequency: Once daily
When to take it: Any consistent time; no evidence-backed clock time is identified
Reference length: 8–16 weeks
Default mix: 4 mL bacteriostatic water → 2.5 mg/mL

Storage

Before mixing: Keep the sealed freeze-dried powder dry and protected from light.
After mixing: Keep upright at 2–8 °C and protected from light; Peak says to use within about 4 weeks (28 days).
Never: Never freeze a reconstituted preparation or use it if it is cloudy or has particles.

How it works

PE-22-28 is a seven-amino-acid fragment developed from spadin research. In a cell assay using human TREK-1 channels, it inhibited TREK-1 current; this does not establish an effect in people.

In mouse behavioural and neuron experiments, the 2017 paper reported changes consistent with antidepressant-like activity, neurogenesis and synaptogenesis. These are preclinical findings, not a treatment for depression.

Illustrated mechanism explainer

What the research shows

The direct 2017 paper measured PE-22-28 TREK-1 inhibition in human-TREK-1-expressing HEK cells with an IC50 of 0.12 nM, compared with 40–60 nM for spadin in the same report.
In mice, the paper used 3.0–4.0 mcg/kg spadin analogues for 4 days in behavioural and hippocampal neurogenesis experiments; this is not a human dose.
The same report tested mouse cortical neurons at 0.1 micromolar and found PSD-95 at 36 hours was about twice the level at 5 hours under its experimental conditions.
ClinicalTrials.gov returned no records for the exact search term PE-22-28 when checked in October 2026, so there is no registered human dose-ranging evidence in that registry search.
PE-22-28 is not an approved medicine in Australia or the United States; the ARTG and Drugs@FDA are the respective official registers reviewed.

Reported side effects

Human adverse effects, pharmacokinetics and interaction risks have not been established because no human clinical record was located in the ClinicalTrials.gov search.
The 2017 cell and mouse work found no effect of PE-22-28 or related analogues on hERG-channel activity under its experimental conditions; that nonclinical result cannot establish human cardiac safety.
Injection-site reactions and other effects are unknown for PE-22-28 in people.

Important notes

Not approved for human therapeutic use in Australia or the United States. Peak supplies this item strictly for in-vitro laboratory research and says it is not intended for human or animal use.
WADA's 2026 S0 class prohibits at all times pharmacological substances with no current approval by a governmental health authority for human therapeutic use. PE-22-28 is not named in the List; athletes should confirm status with their anti-doping organisation.
The chart is attributed to a reference site, not to a human clinical study. The published direct evidence is in cells and mice.
No product-specific LabDoc report is published on Peak's listing, despite its 99% purity label claim.
Never use a mixed vial that is cloudy or has particles in it.

Injection basics

Use a new sterile 1 mL (100-unit) U-100 insulin syringe, 27–31G, every time — never reuse or share.
Wipe the vial stopper and the skin with an alcohol swab and let both dry first.
Inject under the skin (subcutaneously) of the abdomen, thigh or upper arm, and rotate sites.
Put used syringes straight into an approved sharps container — the NDSS lists Australian disposal options.

Guidance: World Health Organization · National Diabetes Services Scheme (NDSS)

06 · QUICK ANSWERS

PE-22-28 questions

How many units is 50 mcg of PE-22-28?

With the default 4 mL mix in a 10 mg vial, the nominal concentration is 2.5 mg/mL. A 50 mcg amount is 2 units, or 0.02 mL, on a U-100 syringe. This is arithmetic for the labelled vial, not a validated human dose.

How much bacteriostatic water is used for a PE-22-28 10 mg vial?

This guide uses 4 mL as the default, making a nominal 2.5 mg/mL concentration. Peak's product page gives a 2 mL measurement example, but 4 mL is selected here because 50 mcg then equals 2 U-100 units rather than 1 unit.

How many units are 100 mcg and 200 mcg of PE-22-28?

At 2.5 mg/mL from a 10 mg vial mixed with 4 mL, 100 mcg is 4 units (0.04 mL) and 200 mcg is 8 units (0.08 mL) on a U-100 syringe.

How long does a 10 mg PE-22-28 vial last?

By nominal vial arithmetic, 10 mg contains 200 daily 50 mcg amounts, 100 daily 100 mcg amounts, 66.7 daily 150 mcg amounts, or 50 daily 200 mcg amounts. Peak's stated 28-day mixed-vial handling period may limit use before the calculated amount is exhausted.

07 · SOURCES