Healing Category
P21
THE NEUROGENESIS BOOSTER
Neurotrophic Peptide P21; CNTF Analog
P21 is an engineered peptide based on ciliary neurotrophic factor (CNTF) that can cross the blood-brain barrier and promote neurogenesis, the growth of new brain cells. It boosts BDNF (brain-derived neurotrophic factor) and has shown promise for cognitive enhancement, Alzheimer's prevention, and stroke recovery.
P21 Evidence Snapshot
How these guides are reviewed- Regulatory status
- Not FDA approved · research use only
- Dosing guidance
- Reviewed by our clinical team
- Linked evidence
- Sources pending
- Content updated
- Aug 28, 2026
Dose and schedule recommendations shown below come from The Peptide App Clinical Team. Research links are provided so readers can inspect the supporting evidence directly.
Quick Answers About P21
Is P21 FDA approved?
No. This profile records P21 as not FDA approved and for research use only.
More context
Review the regulatory and source details on this page for the current context.
What dose does The Peptide App Clinical Team recommend for P21?
Dose: 10 mg daily (subcutaneous, intramuscular, or oral).
More context
Schedule: daily. Cycle: 8 weeks on, 8 weeks off. This is clinical-team guidance for reference and does not replace individualized instructions from a licensed clinician.
What research supports this P21 guide?
No linked research sources are currently available on this guide.
More context
Treat the profile as provisional until supporting sources are published.
What are the side effects of P21?
Reported side effects of P21 include Mild nervousness, Irritability, and Injection site reactions.
More context
They are reported or occasional reactions, not a prediction of what any one person will experience.
Is P21 safe?
P21 has an editorial safety grade of B (Good Safety).
More context
Generally well tolerated with mild side effects. Safety depends on dose, sourcing, health history and medical supervision, so this page does not call it safe for personal use.
Studied Effects & Mechanisms
Neurogenesis
Promotes growth of new neurons in the hippocampus
BDNF Boost
Upregulates brain-derived neurotrophic factor
Anti-Amyloid
Reduces amyloid-beta and tau pathology
Synaptic Plasticity
Enhances NMDA receptor activity for learning
Who is this for
Those concerned about cognitive decline · People wanting to enhance memory and focus · Those with family history of Alzheimer's · Stroke recovery patients
P21 price snapshot
In-stock prices from 15 vendors, checked Oct 14, 2026.
- Vendors
- 15
- Listings
- 15
- Observed range
- $39–$198
Market evidence
P21 product testing and COAs
We found certificates from some of the P21 vendors we track. Based on the certificates our crawler found; vendors may publish more than we index. Research on this page describes the molecule. Vendor certificates concern particular market samples or batches; they do not change the research evidence or establish clinical safety, sterility, or suitability for use.
The clinic network
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