Cognitive

PE-22-28

5.0(1 review)

$50–$208

Prices checked 1 hour ago

Compare vendor offers for PE-22-28, including price, dose, and purity.

Dose size

10mgfrom $50 · 2 vendors8mgfrom $54 · 3 vendors

View all vendors

At a glance · 5 vendors, 5 offers

Avg. vendor rating

4.0

Third-party tested

1/5

COA per batch

2/5

Offers in stock

5 of 5

COA purity range

98.8%

Ships from

1 of 5 vendors third-party tested, COA purity 98.8% across published labs. Prices re-checked 1 hour ago.

As seen on

Where to buy PE-22-28 online

We compare PE-22-28 offers across vetted research vendors so you can buy with confidence. Every price above is pulled from a verified, in-stock listing — here's what to look for before you check out.

Compare vendors on price-per-mg rather than sticker price, and confirm a third-party Certificate of Analysis (COA) is publicly available before you buy. The comparison table above flags self-tested-only results and account-required vendors so you can filter those out first.

Stick to vendors with no unresolved legal issues or community warnings, and check that stock and pricing were verified recently — the "last checked" date on each listing tells you exactly when. Products listed here are intended strictly for laboratory research use.

PE-22-28 Price Comparison

Compare PE-22-28 prices across every verified vendor and supplier, ranked by price, purity, and buyer-rated trust. Use the tabs to filter by size.

Prices last checked Aug 6

Vendor	Rating	Stock	Purity	Value	Price
Amino USA aminousa.com	4.3	In stock	No purity reported	Limited trust signals	$50.00
Modern Aminos modernaminos.com	3.0	In stock	No purity reported	Limited trust signals	$54.00

Amino USA

aminousa.com

Visit Amino USA

Value: Limited trust signals
Price: $50.00
Last checked: 1h ago
Rating: 4.3
Stock: In stock
Purity: No purity reported
Verified
Community signal: Not endorsed
Reddit mentions: 0

Modern Aminos

modernaminos.com

Visit Modern Aminos

Value: Limited trust signals
Price: $54.00
Last checked: 1h ago
Rating: 3.0
Stock: In stock
Purity: No purity reported
Verified
Community signal: Flagged
Reddit mentions: 0

How to Store PE-22-28

Freeze the dry powder. Once mixed with liquid, refrigerate and use within about a month.

Lyophilized Storage

Store at -20°C.

Reconstituted Storage

Refrigerate at 2–8°C, use within 28 days.

Read the full storage guide

A smartphone displaying a "Storage Guide" for peptides, indicating a safe storage temperature range of 2–8°C, with warnings to keep away from light, heat, and freezing. The background is light blue, and additional tips on protecting the peptides are visible below the temperature range.

Compare PE-22-28 Vendors

See which vendors and suppliers are trusted for PE-22-28 — compare price, purity, and buyer trust signals side by side to find the best one to buy from.

Biotech Peptides is a US-based research chemical supplier offering an extensive catalog of 89+ lyophilized peptides and peptide blends, including BPC-157, CJC-1295 DAC, Sermorelin, Tesamorelin, and Follistatin-344, priced roughly $16-$320 per item. The company synthesizes and lyophilizes products domestically, states it verifies purity above 99% using in-house HPLC and mass spectrometry, and publishes Certificates of Analysis, though independent lab identity and testing methodology are not fully disclosed. Products are marketed strictly for research, laboratory, or analytical use and not for human consumption.

Visit store

Sizes

Overview

Value: Fair
Price: $55.00
Rating: 4.0(312)
Verified
Community signal: Flagged
Reddit mentions: 14

Testing & Purity

Purity: 98.8% COA
Testing: Third-party tested: yesCOA per batch: yesMass spectrometry: yes

Ratings

Purity accuracy: 4.5
Price value: 4.0
Shipping speed: 4.5
Packaging: —
Customer service: 4.0

Buying

In stock
Account required
Payments: Card: yesPayment apps: yesCrypto: yesBank transfer: noOther: no
Ships to: United States
Last checked: 1h ago

Core Peptides is a U.S.-based research peptide supplier operating out of Orlando, FL, offering over 80 peptides and blends synthesized and lyophilized domestically with claimed purity levels exceeding 99%. The company positions itself as a chemical supplier for research and laboratory use only, explicitly disclaiming compounding pharmacy status under FDA 503A/503B.

Visit store

Sizes

Overview

Value: Below average
Price: $54.00
Rating: 4.8(281)
Verified
Community signal: Flagged
Reddit mentions: 0

Testing & Purity

Purity: No purity reported
Testing: Third-party tested: noCOA per batch: noMass spectrometry: yes

Ratings

Purity accuracy: 4.7
Price value: 4.1
Shipping speed: 4.5
Packaging: 4.4
Customer service: 4.3

Buying

In stock
Account required
Payments: Card: yesPayment apps: noCrypto: yesBank transfer: yesOther: no
Ships to: United States
Last checked: 1h ago

LIVV Natural is a San Diego, California-based naturopathic medical clinic and med spa, founded in 2016 by Dr. Jason Phan, NMD and Dr. Allison Gordon, NMD, that operates two in-person locations (Little Italy and Cardiff) offering IV therapy, PRP and aesthetic treatments, hormone optimization, and naturopathic consultations. Alongside its clinical services, LIVV runs an online retail peptide line organized by health goal (anti-aging, weight loss, cognitive support, hormone optimization, immune function) sold under a research/development-use disclaimer, including protocol bundles such as the 'Lean & Mean Protocol' (CJC-1295/Ipamorelin, BPC-157, Tesamorelin).

Visit store

Sizes

Overview

Value: Poor
Price: $207.50
Rating: 4.0(171)
Verified
Community signal: Flagged
Reddit mentions: 0

Testing & Purity

Purity: No purity reported
Testing: Third-party tested: noCOA per batch: noMass spectrometry: no

Ratings

Purity accuracy: 4.5
Price value: 2.5
Shipping speed: —
Packaging: —
Customer service: 3.5

Buying

In stock
Account required
Payments: Card: yesPayment apps: noCrypto: noBank transfer: noOther: no
Ships to: United States
Last checked: 3d ago

PE-22-28 Dosage Guide for Cognitive EnhancementPE-22-28 Dosage Calculator

PE-22-28 is an experimental peptide being studied as a fast-acting option for depression, anxiety, and brain protection. It's thought to work by boosting serotonin activity and encouraging new brain cell growth.

Vial size

5 mg

Bacteriostatic water

2 mL

Dosing

500 mcg–1 mg

Frequency

Daily

Cycle

4–8 weeks

Benefit

Cognitive Enhancement

Explore calculators

Basic Dosage Calculator

Calculate peptide doses with our visual syringe guide.

Peptide per vial

Target research quantity

Bac water added

How to reconstitute PE-22-28

View guide

The materials you'll need and step-by-step instructions for safely mixing PE-22-28 with bacteriostatic water.

Materials needed

Your PE-22-28 vial (lyophilized)

Alcohol swabs

Bacteriostatic sterile water

3 mL syringes (Luer Lock tip)

25G or 27G needles (Luer Lock). Other gauges may also be acceptable.

Sharps container (optional)

Remove the caps

Remove the caps from both your PE-22-28 vial and your bacteriostatic water vial.

Sanitize the rubber stoppers

Wipe down the rubber stoppers on both vials with alcohol swabs and let them dry for about 3 minutes.

Attach the needle

Take your 3 mL syringe and needle. Twist the needle's plastic hub into the Luer Lock tip on the syringe to secure it.

Draw the bac water

Pull back on the plunger to draw your desired volume of bacteriostatic water. If you overfill, just push the excess back in until you reach the right marker on the syringe.

How much bac water? PE-22-28 typically comes in a 5 mg vial. We recommend 2 mL of bacteriostatic water, though anywhere between 1 mL and 3 mL is acceptable. For larger vials you can use up to 5 mL — more bac water makes microdosing easier, but insulin needles usually max out at 1 mL per injection. That means a lot of bac water might force you into multiple injections to hit your target dose. Unless you're microdosing, 2 mL per vial is a solid rule of thumb.

Insert the needle into the PE-22-28 vial

With the bac water in your syringe, insert the needle into the PE-22-28 vial at a slight angle to avoid pressure buildup.

Use a thin needle: Stick to 25G or higher to avoid damaging the rubber stopper. Higher gauge means a thinner needle.

Release the water gently

Let the water run gently down the side of the vial. Don't inject it forcefully.

Heads up: Sometimes the plunger pushes itself in as soon as the needle enters the vial. Hold the plunger back so you have full control over how fast the bac water enters.

Swirl to dissolve

Avoid shaking. Gently swirl, flip, and roll the vial to dissolve the powder.

Be patient: This usually takes 2 to 5 minutes of consistent swirling, mixing in a circular motion, and gently flipping the vial up and down. The water needs to run through the powder many times to fully dissolve it. Don't shake or get aggressive with it.

Check for full dissolution

The solution should be clear with no visible particles. If it's cloudy or clumpy, wait a minute and repeat the swirling step.

Cap, dispose, and store

Once you're done, cap the needle and dispose of it (ideally in a sharps container). Store the reconstituted PE-22-28 vial in the fridge whenever it's not in use. It will stay good for approximately 30 days.

How We Rank Offers

We don't just sort by price. Here's how each offer's rating actually gets calculated.

Compared Apples to Apples

We score price per mg against other offers of the same dose size, not the sticker price, so a bigger vial doesn't look like a worse deal than it is.

Price Is Only Part of the Score

We weigh price-per-mg alongside vendor rating, COA purity, and account requirements, so a cheap offer from an unproven vendor won't outrank a fair price from a trusted one.

Trust Gates the Top Ratings

A sub-4.0-rated vendor can't earn "Great value," and missing third-party purity data caps an offer out of "Good" or "Great." No price is low enough to buy around it.

Vendor Trust Signals

We don't sell PE-22-28 ourselves — every vendor below is vetted and rated independently before being listed here.

Core Peptides — 4.8/5 (281 reviews)

Based in US, no account required to view pricing.

Amino USA — 4.3/5 (18 reviews)

Public, third-party tested COAs on every batch, based in US, account required to view pricing.

Biotech Peptides — 4.0/5 (312 reviews)

Public COAs on every batch, based in US, no account required to view pricing.

Compare all vendor reviews

PE-22-28 Buying FAQ

Straight answers on legality, pricing, and vendor vetting before you buy. For research reference only.

PE-22-28 is typically supplied as a lyophilized (freeze-dried) powder that is reconstituted with bacteriostatic water, injected gently down the vial wall and swirled (not shaken) until dissolved. Once reconstituted, it's generally kept refrigerated at 2–8°C and used within a few weeks; the unreconstituted powder should be stored in a freezer or refrigerator away from light. Always follow the specific handling instructions provided by the supplier.

Because no formal human safety trials exist, there is no confirmed human side-effect profile. Anecdotal and preclinical reports mention mild, transient effects such as nasal irritation (with intranasal use), minor injection-site reactions, and occasional headache or fatigue, but this data has not been rigorously validated. Anyone considering research use should treat it as an unstudied compound and account for potential interactions with serotonergic medications.

PE-22-28, Selank, and Semax are all short peptides studied for mood and cognitive effects, but they work through different mechanisms: PE-22-28 acts on TREK-1 potassium channels and is linked to serotonergic mood effects, Selank is a tuftsin-derived anxiolytic peptide, and Semax is an ACTH-fragment analog associated with cognitive and neurotrophic effects. Because their proposed mechanisms differ, they are sometimes studied or stacked together in informal research protocols targeting complementary aspects of mood and cognition.