Best P21 Vendors in 2026
Cognitive / NeuroRanked 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 7 tracked vendors, prices range from $84.99 to $1149.50, verified by Peptide Compare on 23 Sep 2026. Prices are scraped from vendor sites; trust scores come from Finnrick blind tests.
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- Cheapest per mg
- $8.50/mgat Soma Chems
- Highest trust score
- Simple Peptide(7.0/10)
- In stock now
- 5 products across 7 vendors
- Last verified
- Sep 23, 2026
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Top P21 vendors at a glance
| Rank | Vendor | Trust score | Per mg |
|---|---|---|---|
| #1 | Simple Peptide | 7.0/10 | $19.80 |
| #2 | SwissChemsOut of stock | 4.0/10 | $229.90 |
| #3 | Soma Chems | untested | $8.50 |
| #4 | Protide Health | untested | $11.00 |
| #5 | Alpha Omega | untested | $19.80 |
| #6 | Real PeptidesOut of stock | untested | $20.00 |
| #7 | Genetic Peptide | untested | $24.00 |
All 7 ranked P21 vendors
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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.