P21
Also known as: P021, CNTF peptide derivative
P021 | CNTF-Derived Neurogenic Peptide
Overview
P21 is a nootropic peptide derived from ciliary neurotrophic factor (CNTF) that enhances neurogenesis and cognitive function. It contains an adamantane moiety that enables blood-brain barrier penetration. Research shows it increases BDNF expression, inhibits LIF signaling to promote neurogenesis, and reduces tau and amyloid pathology in Alzheimer's disease models. Remarkably, P21 can boost neurogenesis in diseased brains above levels seen in healthy untreated brains.
Key benefits
- Potent promotion of neurogenesis in the dentate gyrus
- Increased BDNF expression
- Reduced tau protein pathology
- Reduced amyloid-beta plaque formation
- Improved cognitive function and memory
- Restored synaptic deficits in cortex and hippocampus
- Reduced mortality rate in AD models
- Crosses blood-brain barrier effectively
Mechanism of action
P21 operates through multiple pathways: it inhibits leukemia inhibitory factor (LIF) signaling, removing a key roadblock to neurogenesis and shifting the brain toward a more embryologic state favoring neuron growth. It increases brain-derived neurotrophic factor (BDNF) expression and activates the BDNF/TrkB/PI3-K/AKT/GSK3β pathway. This pathway modulation improves cognitive function and reduces tau and amyloid pathologies.
Molecular data
- Type
- CNTF-derived peptide
- Half-life
- Over 3 hours (mouse plasma)
Indications
What the research community uses this compound for, with self-reported effectiveness.
Neurodegenerative Disease
Alzheimer's Disease
EffectiveP021 markedly reduced tau pathology, attenuated Aβ generation, and rescued episodic memory impairment in 3xTg-AD mice.
Neurodegeneration Prevention
EffectiveTreatment during synaptic compensation period can prevent neurodegeneration and reduce mortality.
Tau Pathology
EffectiveRobust attenuation of tau pathologies through BDNF/TrkB/PI3-K/AKT/GSK3β pathway.
Cognitive Enhancement
Neurogenesis
Most effectiveEnhances dentate gyrus neurogenesis so effectively it exceeds levels in healthy untreated brains.
Memory Processes
EffectiveEnhances memory processes through increased BDNF and restored synaptic function.
Age-Related Cognitive Decline
ModerateMay reduce natural decline in learning and memory in aged models by rescuing neurogenesis deficit.
Neuroprotection
Synaptic Plasticity
EffectiveRestores synaptic deficits in cortex and hippocampus.
Neuronal Plasticity
EffectiveRescues deficits in neuronal plasticity.
Dosing protocols
Common protocols by delivery method. Adjust the curve below to model accumulation in your own cycle.
Injectable
P21 has not yet been tested in human clinical trials. Research protocols in animal models use subcutaneous or intraperitoneal injection. The adamantane moiety enables blood-brain barrier penetration for CNS effects.
| Protocol | Dose | Frequency | Route / duration |
|---|---|---|---|
| Research protocol | Variable by study | Daily | SubQ or IP |
Preparation
You will need
- Bacteriostatic water (BAC)
- Insulin syringes
- Alcohol swabs
- Peptide vial
- Sterile work surface
Steps
- Clean work area and hands thoroughly
- Calculate required BAC water volume
- Draw BAC water into syringe
- Inject slowly down vial side
- Gently swirl until dissolved (never shake)
- Store in refrigerator
Work out the water volume and syringe units in the reconstitution calculator →
Interactions
Pairwise interactions with other compounds you might be cycling — the same data behind the cycle builder's safety check.
Timeline
Typical week-by-week effects reported in clinical and observational data.
- Days-Weeks
BDNF elevation begins
- Weeks
Neurogenesis enhancement measurable
- Weeks-Months
Cognitive improvements in research models
- Long-term
Disease-modifying effects in AD models
Safety
Reported adverse effects, contraindications, and what to monitor on cycle.
Common side effects
- Limited data - primarily preclinical research
- Generally well-tolerated in animal studies
Rare side effects
- Unknown - insufficient human data
Stop signs — stop and seek advice
- Allergic reactions
- Unusual neurological symptoms
Contraindications
- Not approved for human use
- Pregnancy or breastfeeding
- Unknown safety profile in humans
Monitoring
- Experimental peptide - medical supervision essential
- No human clinical trials completed
Quality checks
What a legitimate product looks like, what should give pause, and what should make you stop.
Good signs
- White lyophilized powder
- Clear solution after reconstitution
- High purity (>95%)
- Intact vacuum seal
Warning signs
- Research chemical - limited quality standards
Stop signs — don't use
- Discoloration
- Cloudy solution
- Particulates visible
References
Primary literature and clinical-trial data informing this entry.
P021 Treatment in 3xTg-AD Mice
Journal of Alzheimer's Disease · 2018
P021 markedly reduced tau pathology, attenuated Aβ, rescued episodic memory, and reduced mortality in AD mice.
P21 and BDNF/TrkB Pathway
Neuropharmacology · 2019
Disease-modifying effect via BDNF/TrkB/PI3-K/AKT/GSK3β pathway; rescued neurogenesis and cognition.
P21 in Cognitive Aging
Neurobiology of Aging · 2017
May reduce age-related cognitive decline by restoring BDNF expression and synaptic function.
P21 as Promising AD Drug Candidate
Alzheimer's Research & Therapy · 2020
Beneficial effects in preclinical studies make P21 highly promising for AD drug development.
Last updated . How this page was sourced is described in the methodology.