Quick Facts
What is P21?
P21 (P021) is a synthetic peptide designed to mimic the effects of brain-derived neurotrophic factor (BDNF). Unlike BDNF itself, P21 can cross the blood-brain barrier when administered peripherally. It was developed at the New York State Institute for Basic Research for Alzheimer's disease treatment. P21 promotes neurogenesis in the hippocampus and inhibits GSK-3β, an enzyme implicated in Alzheimer's pathology.
How Does P21 Work?
P21 acts as a BDNF mimetic, activating TrkB receptors and downstream signaling pathways. This leads to increased neurogenesis in the hippocampus, enhanced synaptic plasticity, and inhibition of GSK-3β (glycogen synthase kinase-3β). GSK-3β inhibition reduces tau phosphorylation, a key factor in Alzheimer's disease. The combined effects support learning, memory, and neuroprotection.
Research-Backed Benefits
Neurogenesis
Moderate EvidencePromotes birth of new neurons in the hippocampus.
Memory Enhancement
Moderate EvidenceImproves spatial and working memory in animal models.
GSK-3β Inhibition
Moderate EvidenceMay reduce tau pathology relevant to Alzheimer's disease.
BBB Penetration
Strong EvidenceCan cross blood-brain barrier unlike BDNF itself.
Dosage Guidelines
Disclaimer: This content is for educational purposes only. Peptides are research compounds not approved by the FDA for human use. Always consult with a qualified healthcare provider.
Orally bioavailable. Early morning dosing often preferred. Research dosing still being optimized.
Side Effects & Safety
- Limited human safety data
- Generally well tolerated in animal studies
- Possible headache
- Long-term effects unknown
Frequently Asked Questions
References
- Bolognin S, et al. "P021 cognitive enhancement." Neurobiol Aging, 2014. PMID: 24792908
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