P21 Peptide
Also known as: P021 · CNTF(63-82)aa
A synthetic peptide derived from ciliary neurotrophic factor (CNTF) that increases BDNF production, enhances neuroplasticity, and improves cognitive function. Shows promise for Alzheimer's disease, depression, and age-related cognitive decline.
What is P21 Peptide? A synthetic peptide derived from ciliary neurotrophic factor (CNTF) that increases BDNF production, enhances neuroplasticity, and improves cognitive function. Shows promise for Alzheimer's disease, depression, and age-related cognitive decline.
How does P21 Peptide work? P21 activates CNTF receptors and downstream JAK/STAT3 and MAPK signaling pathways that upregulate BDNF expression. Unlike Semax which increases BDNF acutely, P21 appears to sustainably increase BDNF production and promotes adult neurogenesis in the hippocampus.
Benefits of P21 Peptide: Sustainably increases BDNF production; Promotes adult neurogenesis in hippocampus; Improves memory and learning; Reduces cognitive deficits in Alzheimer's models; Potential antidepressant effects; Distinct mechanism from Semax/Selank
P21 Peptide dosage: Research dose: 5-10mg/day subcutaneous. Limited human data — most research in rodent models.
Research status: Research Only
Source: PeptideWiki — https://www.peptide-wiki.net/peptides/p21-peptide
Mechanism of Action
P21 activates CNTF receptors and downstream JAK/STAT3 and MAPK signaling pathways that upregulate BDNF expression. Unlike Semax which increases BDNF acutely, P21 appears to sustainably increase BDNF production and promotes adult neurogenesis in the hippocampus.
Benefits
- Sustainably increases BDNF production
- Promotes adult neurogenesis in hippocampus
- Improves memory and learning
- Reduces cognitive deficits in Alzheimer's models
- Potential antidepressant effects
- Distinct mechanism from Semax/Selank
Side Effects & Risks
- Limited human data
- Injection site reactions
- Headache
Where to Buy P21 Peptide
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$179.99
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Storage & Reconstitution Guide
Storage Temperature
-20°C (lyophilized)
24 months (lyophilized), 28 days (reconstituted)
Reconstitution Solvent
Bacteriostatic water (BAC water)
Swirl gently — do not shake or vortex
Handling Notes
Protect lyophilized peptide from moisture and light. Once reconstituted, keep refrigerated. Discard if solution becomes cloudy or discolored. Use insulin syringe for precise dosing.
Step-by-Step Reconstitution
Gather supplies
BAC water, insulin syringe, alcohol swabs, vial
Disinfect tops
Swab rubber stoppers of both vials with alcohol
Draw BAC water
Pull desired mL of BAC water into syringe
Inject slowly
Inject BAC water down the side of the peptide vial, swirl gently to dissolve
Research Protocol
- Dose Range
- 5–10 mg
- Frequency
- Once daily subcutaneous injection
- Cycle
- 4-8 weeks
- Routes
- subcutaneous injection
- Notes
- Research dose: 5-10mg/day subcutaneous. Limited human data — most research in rodent models.
Legal & Regulatory Status
Sold for research purposes only. Not for human use. Laws vary by country.
Commonly Stacked With
View all peptide stacks →External Resources
PeptideWiki Research Team
Evidence-based research data sourced from PubMed and ClinicalTrials.gov · Last updated: February 25, 2026
Frequently Asked Questions About P21 Peptide
What is P21 Peptide?▾
A synthetic peptide derived from ciliary neurotrophic factor (CNTF) that increases BDNF production, enhances neuroplasticity, and improves cognitive function. Shows promise for Alzheimer's disease, depression, and age-related cognitive decline.
What are the benefits of P21 Peptide?▾
Sustainably increases BDNF production
What are the benefits of P21 Peptide?▾
Promotes adult neurogenesis in hippocampus
What are the side effects of P21 Peptide?▾
Limited human data
What is the recommended dosage for P21 Peptide?▾
Research dose: 5-10mg/day subcutaneous. Limited human data — most research in rodent models.
How long should a P21 Peptide cycle last?▾
4-8 weeks
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