PE-22-28: the complete guide.

The short version.

If you read nothing else, read this. The whole guide in a handful of bullets.

Quick reference.

What is PE-22-28?

PE-22-28 is a short peptide, which simply means a small chain of amino acids, the building blocks that make up the proteins in your body. It is seven amino acids long, which is why researchers call it a heptapeptide.

It is a refined version of a natural peptide called spadin. Spadin is a fragment of the propeptide of sortilin, a protein your body already makes. Researchers led by Mazella first described spadin in 2010 as a natural blocker of the TREK-1 potassium channel with antidepressant-like effects. In 2017 a team led by Djillani trimmed spadin down to residues 22 through 28, which is where the name comes from, and that shorter piece turned out to be far more potent and longer lasting.

The version sold by vendors arrives as a freeze-dried white powder in a small sealed vial. It is not a steroid, not a hormone, and not a stimulant. People reach for it for one theme above all: supporting mood and studying how a TREK-1 blocker affects the brain, including the growth of new neurons.

Worth saying plainly: PE-22-28 has never completed a human clinical trial. The exciting results, the antidepressant-like effects and the new neuron growth, come from mice. It is sold strictly for research use only, and there is no validated human dose or human safety data. We get into what that means further down.

How it works in the body.

You do not need a biology degree to follow this. Here is the simple picture, then a little more for the curious.

The core idea is that PE-22-28 blocks a single specific channel in the brain called TREK-1. When that channel is blocked, certain mood-related neurons become a little more active, and downstream that is linked to both an antidepressant-like effect and new neuron growth.

• TREK-1 blockade. TREK-1 is a two-pore potassium channel that normally calms neurons down. PE-22-28 selectively blocks it, which makes serotonin-releasing neurons more likely to fire. Mice bred without TREK-1 are naturally resistant to depression, which is what made this channel an interesting target.
• More serotonin signaling. By nudging serotonergic neurons toward firing, PE-22-28 is studied for raising serotonin tone, the same broad system that many conventional antidepressants act on, but through a completely different mechanism.
• Neurogenesis. Over weeks, the rodent work showed increased growth of new neurons in the hippocampus, a region tied to mood and memory. This is the slower, build-over-time side of what PE-22-28 is studied for.

How to take it: routes of administration.

PE-22-28 is used two ways. The most common community route is an intranasal spray, because it can reach the brain through the nasal nerves without a needle. Some people inject it subcutaneously instead. Here is the honest comparison.

So which should a beginner pick? For most people the nasal spray is the default: no needle, and the route lines up with the brain-focused reason people are interested in PE-22-28 in the first place. Subcutaneous injection is the option if you want more precise, repeatable dosing and do not mind a tiny needle.

Dosing by goal.

There is no single official dose for PE-22-28, because it is not an approved medicine and has never completed a human trial. What follows is the range people commonly run, scaled from animal research and anecdote. Treat every number here as a starting point, not a prescription.

Common range

Most community protocols land at about 100 to 300 mcg per day, taken once in the morning. People often start at the low end to gauge how they respond before moving up. The intranasal and subcutaneous ranges are broadly similar.

When to take it

Morning dosing is the norm, since the effect is on alertness and mood rather than sleep. Consistency at the same time each day matters more than the exact clock time.

Stacked with Semax or Selank

PE-22-28 is often run alongside another nasal nootropic. The PE-22-28 schedule stays the same; Semax or Selank is dosed on its own rhythm. People keep doses separate enough to tell what is doing what.

Cycling and timing.

A cycle just means a defined run of time on the peptide, followed by a break. For PE-22-28 the common pattern is roughly 4 to 8 weeks on, then a 2 to 4 week break, rather than running it indefinitely.

Why not just run it forever? Mostly because the long-term human safety data does not exist at all. The cautious and widely followed approach is to run a focused block, then stop and reassess.

• Hold the schedule through your on-weeks, once a day at roughly the same time.
• Take a real break of a few weeks between cycles rather than running it back to back.
• Reassess after each cycle. If you are using it for a mood issue, that is a conversation for a licensed provider, not a forum.

Stacking PE-22-28.

PE-22-28 is often run with another nasal nootropic, because the goals overlap and the routes match. These are the pairings the community reaches for.

See full recipes, dosing, and how people run them on the stacks page.

Side effects and safety.

In the reports we see, PE-22-28 is generally described as well tolerated, with side effects that tend to be mild and temporary when they show up at all. The ones people mention most often are:

• Nasal irritation from the spray, usually mild and often eased by hydration or a saline rinse.
• Mild headache in the first few days, which tends to settle on its own.
• Lightheadedness shortly after a dose for some people.
• Nothing well characterized beyond that, simply because there is so little human data to draw on.

Who should be cautious.

Some people have clear reasons to be extra careful, or to avoid PE-22-28 entirely until they have spoken with a licensed provider.

• Pregnant or breastfeeding. There is no safety data here, so this is a hard avoid.
• Anyone managing depression or another mental health condition. A research peptide is not a treatment, and self-managing a serious condition is risky. This is a conversation for a licensed provider.
• Competing athletes. PE-22-28 falls under WADA's non-approved substances category and will count as prohibited.
• Anyone on other medications, especially antidepressants or anything affecting serotonin. If you take prescription drugs or manage a chronic condition, talk to your provider first.

And the universal one: whoever you are, talk to a licensed healthcare provider before starting PE-22-28. This guide is educational, not a substitute for personalized medical advice.

Where to buy it safely.

This is where a lot of beginners get burned, because peptide quality varies wildly between vendors and the cheapest vial is not always the real deal. Our honest take: do not shop on price alone, shop on price plus independent lab data.

• Compare vendors side by side. Price ranges are wide, and the difference between the lowest and highest listing can be large for the exact same compound.
• Look for recent third-party lab tests. The gold standard the community looks for is a recent Janoshik certificate of analysis showing purity for the batch you are actually buying.
• Favor recent COAs. An old lab result on a different batch tells you little. The fresher the test, the more it means.
• Be skeptical of suspiciously cheap listings with no testing behind them.

That is exactly the comparison we put together. On our PE-22-28 product page you can compare vendor prices, see which batches have public lab data, and view the grades we assign from that data. From there you can head to the buy page to line up your options.

Questions, answered straight.