PEPTIDE
Verified Peptide ReviewLast reviewed: 19 April 2026

Compound Profile · Cognitive

P21

P21 is a synthetic dipeptide investigated in research for neuroprotective and cognitive-support effects.

LegalResearch onlyEvidenceEmergingHuman useNot approved
6.0/ 10

Peptide Score

Evidence

6.0

Safety

6.4

Regulatory

5.6

Transparency

6.0

Quick verdict

Very limited published research. Efficacy and mechanism are not well-established.

Reality check

What this isn't

  • Not approved for human use — research-only context
  • No regulator has approved human use
  • Evidence base is early — long-term data limited
  • Side-effect profile not fully characterised
  • Educational only — not medical advice

Deep dive

Full P21 review

A synthetic dipeptide.

Studied for neuroprotection in research contexts.

CompareResearch-gradeSafety