PE-22-28 (Mini-Spadin)

PE-22-28 is the name used in research literature for a synthetic peptide modeled on spadin, a natural fragment produced from the sortilin protein. It is studied as a stabilized analog with selective activity at the TREK-1 potassium channel, a channel of interest in neuroscience research.

PE-22-28 has not been evaluated by the FDA, is not a registered drug or dietary supplement, and is not intended for human or animal use. On this site it is classified strictly as a research-reference compound: a subject of laboratory study, not a product for consumption or administration.

Quick facts

• Origin: a synthetic analog of spadin, a peptide fragment naturally derived from the sortilin protein.
• Reported target: the TREK-1 potassium channel, as referenced in published neuroscience literature.
• Category: an investigational research peptide, used only in laboratory and academic settings.
• Regulatory status: not FDA-evaluated, not a registered drug, and not assessed for safety in humans or animals.
• Intended use: reference material for laboratory research only, not for human or animal administration.

Because PE-22-28 is a research compound with no regulatory approval for clinical use, published findings about it should be read as preliminary and specific to their original study conditions, not as a general statement about the compound. It is typically supplied to laboratories as a lyophilized (freeze-dried) powder, which must be reconstituted into solution before it can be measured or handled in a research setting. General reconstitution workflow, separate from any compound-specific detail, is covered later in this article.

All of our reusable peptide pens (V1, V2, V3 and Gansulin) are compared on one page.

This overview covers the reconstitution hardware used alongside PE-22-28 vials in a research workflow: cartridge and pen mechanics only. PreppinPeppers supplies hardware for research use only; we do not sell compounds, and this reference does not cover dosing, administration, or outcomes.

Which cartridges fit the pens?

Our pens take standard 3 ml (300-unit) glass cartridges with the 11 mm long plunger (stopper), the cartridge we sell. 3 ml cartridges are also made with a shorter, about 8 mm plunger, and a pen is built for one height, so check that a cartridge from another source has the 11 mm long plunger before loading it; the glass looks identical from the outside. Check stopper length before loading a cartridge into any of our pens.

Do the cartridges work with other pens too?

We've only verified fit within our own hardware line. We have not tested our cartridges in third-party pens, so we can't confirm compatibility outside our own system — always check stopper length against your specific pen's documentation first.

All PreppinPeppers pens accept universal 28G–33G screw-on pen needles, sold separately for lab workflow use.

What it is

PE-22-28 is a short, lab-synthesized peptide, a small chain of amino acids, the building blocks of proteins. It is derived from spadin, a natural fragment the body produces from a larger protein called sortilin.

• Classification: peptide research compound
• Parent fragment: spadin, sourced from sortilin
• Reported target: TREK-1, a potassium channel

In the research literature, PE-22-28 is described as a selective blocker of the TREK-1 channel. TREK-1 is a protein found in brain cells that acts like a gate, controlling the flow of potassium — a charged particle — in and out of the cell. Blocking that gate is reported to change how the cell sends electrical signals. This entry is provided as background reference for laboratory researchers studying PE-22-28, not as guidance for use in humans or animals.

Research context and categorization

Background and Development

PE-22-28 is categorized under neuroscience, mood, and cognition research, within a subgroup of peptides studied for their effect on ion channels — the gated proteins in a cell membrane that control the flow of charged particles, similar to valves in a pipe.

• Origin: designed as a shorter, more metabolically stable analog of spadin.
• Spadin: first described around 2010 as a naturally occurring TREK-1 potassium channel blocker studied in animal models.
• Category placement: ion-channel-modulator subgroup, within the broader neuroscience, mood, and cognition research family.

Preclinical Targets and Research

Research interest centers on PE-22-28's relationship to the TREK-1 channel. In laboratory animals, genetic absence of this channel is associated with a depression-resistant behavioral profile in standardized tests. This link is the basis for studying PE-22-28 in connection with:

• Mood-related behavior in animal models
• Neurogenesis — the formation of new brain cells
• Neuroprotection — shielding existing brain cells from damage

All of this work takes place in cell cultures and animal models, not in people. Some research reports describe a faster onset and longer duration of effect compared with spadin, the parent peptide it was derived from, which researchers attribute to its shorter, more stable structure.

Key point: PE-22-28 is strictly for investigational use. There are no completed, published human trials, and nothing described in this section confirms or represents an approved outcome in people.

Status

Regulatory Status

PE-22-28 is not approved by any regulatory agency for human or animal use. It is supplied and handled strictly as a research-only compound, intended for laboratory and non-clinical use. Published data are limited to cell-based and rodent studies; no clinical trials in humans have been conducted or reported. Regulatory status can change, so check current guidance before relying on it.

Sport / Anti-Doping Status

PE-22-28 is not listed by name on the current WADA Prohibited List, and TREK-1 channel blockers are not named as a class either. The list uses broad category language and is updated at least annually, so a compound's absence by name does not guarantee it falls outside every category. Anyone with a competitive-sport concern should check the official, current WADA Prohibited List directly rather than relying on this summary.

Reconstitution notes (general)

Reconstitution means dissolving a dry powder in liquid to create a working solution at the lab bench. Concentration is simple math: milligrams of peptide in the vial divided by millilitres of diluent added. More diluent makes a weaker solution; less diluent makes a stronger one. Use the peptide calculator to work out the exact concentration for a specific vial.

Diluent choice matters for solution stability. Bacteriostatic water commonly contains benzyl alcohol as a preservative, and benzyl alcohol is documented in the literature as a factor that can affect the stability of some peptides in solution over time — another reason to prepare only what a session's testing requires and to record vial-specific notes rather than relying on general assumptions.

Dilution and handling notes (compound-specific)

PE-22-28 is supplied as a lyophilized (freeze-dried) powder, most often in vials holding 5 mg to 10 mg. It is dissolved in bacteriostatic water (a sterile water with a small amount of preservative that slows bacterial growth). Common lab references suggest using roughly 1 mL to 3 mL of bacteriostatic water per vial. For a 10 mg vial, that gives a concentration of about 3 to 10 mg per mL.

How much water you use is a trade-off. Less water gives a stronger, smaller-volume solution. More water makes it easier to measure small amounts accurately.

That preservative is typically benzyl alcohol at a low concentration - an additive, not an inert filler. A reconstituted vial is not indefinitely stable: lab references cite time, temperature, light and freeze-thaw cycles as the main factors, generally favoring cold, dark storage.

Mixing Instructions

PE-22-28 has parts of its structure that do not mix easily with water (called hydrophobic residues, meaning they tend to push water away). Because of this, a freshly mixed vial may look slightly cloudy at first and may take longer to fully dissolve than other peptides. To mix it properly:

1. Add the water slowly along the inner wall of the vial, not directly onto the powder.
2. Let the vial sit, then swirl or roll it gently until the liquid turns clear. Do not shake it. Shaking causes foam and can stress the peptide.
3. Let the powder and the water reach room temperature before mixing. This helps the powder dissolve and reduces cloudiness.
4. If the solution is still cloudy or has visible bits floating in it after gentle mixing and resting, treat that as incomplete dissolution. It is not ready to use yet.

Handling and storage

Keep the reconstituted (dissolved) solution refrigerated at 2 to 8 C and away from direct light. Wipe the rubber stopper with an alcohol swab before each use. Write the mix date on the vial label so you always know how old the solution is.

Plan to use or discard the reconstituted solution within a general four-week refrigerated window. If the powder has not been mixed yet, keep it frozen for longer-term storage as your supplier directs.

When to Discard

Discard the solution right away if you notice any of the following:

• It turns cloudy after it had already gone clear
• It changes color
• It has floating bits or visible particles in it

Frequently asked questions