Which vendor has the cheapest P21?

Soma Chems currently offers the lowest price per mg at $8.50/mg. Prices are updated daily from vendor websites.

Which P21 vendor is most trusted?

Simple Peptide has the highest Finnrick trust score (7.0/10) among vendors selling P21. Finnrick scores are based on independent blind purity testing.

Is P21 third-party tested?

Finnrick blind-testing data drives our rankings. Independent Janoshik test reports are not yet available for these vendors — check individual vendor pages for any purity documentation they publish.

How many vendors sell P21?

We currently track 8 vendors selling P21, with 5 products in stock. Inventory and pricing are updated daily.

Best P21 Vendors in 2026

Cognitive / Neuro

Ranked by Finnrick trust score, purity testing, and price.

Simple Peptide is our #1 pick for P21, with a Finnrick trust score of 7.0/10. Across 8 tracked vendors, prices range from $61.98 to $1149.50. Rankings combine independent purity testing data, vendor trust scores, pricing, and stock availability. We never accept payment for placement.

Cheapest per mg: $8.50/mgat Soma Chems
Highest trust score: Simple Peptide(7.0/10)
In stock now: 5 products across 8 vendors
Last verified: Aug 8, 2026

Simple Peptide

Top Pick

7.0/10

$198.00(10mg)— $19.80/mg

In Stock

Check Price

SwissChems

4.0/10

$1149.50(5mg)— $229.90/mg

Out of Stock

Check Price

Behemoth Labz

$61.98(10mg)— $6.20/mg

Out of Stock

Check Price

Soma Chems

$84.99(10mg)— $8.50/mg

In Stock

Check Price

Protide Health

$110.00(10mg)— $11.00/mg

In Stock

Check Price

Alpha Omega

$198.00(10mg)— $19.80/mg

In Stock

Check Price

Real Peptides

$100.00(5mg)— $20.00/mg

Out of Stock

Check Price

Genetic Peptide

$120.00(5mg)— $24.00/mg

In Stock

Check Price

How we rank vendors

Our composite score weighs Finnrick blind-testing trust scores (62%), price competitiveness (25%), and stock availability (13%). Vendors without Finnrick data are sorted by price below scored vendors. We never accept payment for rankings. Learn more.

Compare all P21 vendors by price →

More Cognitive / Neuro buying guides

Last updated: August 8, 2026