P-21
A peptide derivative of CNTF (Ciliary Neurotrophic Factor) that mimics its neurogenic and neuroprotective effects.
Common Dosage
1mg daily (Research)
Category
Nootropic
- Cognitive enhancement
- Neuroplasticity
- BDNF upregulation
P-21 is a synthetic peptide derived from ciliary neurotrophic factor (CNTF), a cytokine with established roles in neuronal survival, differentiation, and synaptic plasticity. CNTF itself has been investigated clinically (notably for ALS and obesity) but had significant tolerability issues including weight loss, fevers, and immune activation. P-21 was developed as a small peptide fragment that captures key neurogenic activities of CNTF without systemic cytokine-like side effects.
P-21 is believed to bind to a component of the CNTF receptor complex, triggering downstream JAK/STAT3 signaling that promotes neurogenesis, enhances BDNF production, and supports dendritic remodeling. The increase in BDNF (Brain-Derived Neurotrophic Factor) is particularly significant — BDNF plays a central role in learning, memory consolidation, and resilience to neurodegeneration.
- Cognitive enhancement and memory consolidation
- BDNF upregulation for neuroprotection
- Adult hippocampal neurogenesis support
- Depression and mood disorder research
- Age-related cognitive decline prevention
- Down syndrome cognitive improvement research (animal models)
Cognitive Enhancement in Animal Models
Rodent studies demonstrated significant improvement in spatial memory and learning tasks following P-21 treatment, correlated with increased hippocampal neurogenesis and BDNF protein levels. Trisomy 21 mouse models showed notable cognitive correction — a finding with implications for Down syndrome research.
- Human clinical data does not exist — all efficacy information is from animal models
- CNTF signaling system has broad effects; immune and inflammatory off-target activation is possible
- BDNF upregulation in tumor microenvironments is theoretically concerning for cancer promotion
- Appropriate human dosing is entirely unknown
- Side effects including fatigue and headache are reported anecdotally
- Fatigue
- Headache