← Back to Cognitive Deep Dive

P21

CNTF-derived peptide fragment — neurogenesis promoter

Protocol Summary

Route
SubQ
Dose Range
1–2 mg/day
Cycling
30 days on, variable off period
Evidence Tier
animal

Primary Benefits

Safety Profile

Limited data. Generally well-tolerated in animal studies. No human clinical trials.

Research Findings

from peptide_kb — updated weekly

clinical-anecdotal clinical-anecdotal (1)

Peptides vs Supplements for Cognitive Enhancement — Dihexa, P21, Semax, Selank
youtube 2026-06-07 source →
Supplement formulator compares neuropeptides to traditional nootropics. Dihexa described as 'hundreds of times more powerful than lion's mane' for neurogenesis. P21+Dihexa combined in 'Neurorigen' product. Semax compared to alpha-GPC but far more potent. All peptides positioned as tools to combat neurodegenerative disease beyond what supplements alone can achieve. Also discusses dopamine resensitization via Semax, P21, Dihexa.