P21 is a small tetrapeptide mimetic modeled on CNTF, a nerve growth factor. In animal work it promotes neurogenesis, raises BDNF, and shows disease-modifying effects in Alzheimer's models, with intranasal delivery exploiting nose-to-brain transport that bypasses the blood-brain barrier. No human trials have been completed, so it sits squarely in experimental territory.
- Promotes neurogenesis and raises BDNF, the brain's own growth factor, in animal models.PubMed (P021 neurotrophic)
- Inhibits leptin-pathway-linked tau pathology and shows disease-modifying effects in Alzheimer's models.PubMed (P021 neurotrophic)
- Intranasal delivery exploits nose-to-brain transport, bypassing the blood-brain barrier.PubMed (P021 neurotrophic)
- Effects in the models are cumulative and build over weeks, not an acute nootropic hit.thepeptidereport
- Straight talk: no completed human trials exist, so all of this rests on animal and mechanistic data.The Complete Peptide Guide