P21 (P021)
Also known as: P21, P021
P21 (P021) is a small peptidergic compound derived from the active region of ciliary neurotrophic factor, studied for promoting neurogenesis and synaptic plasticity. It is researched preclinically as a neuroprotective and cognition-enhancing agent.
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Mechanism of Action
P21 is a tetrapeptide mimetic engineered from the biologically active site of ciliary neurotrophic factor (CNTF), modified with adamantylation to improve stability and blood-brain-barrier penetration. It enhances brain-derived neurotrophic factor (BDNF) signaling through the TrkB receptor, promoting hippocampal neurogenesis and dendritic spine density. In animal models it also inhibits abnormal tau hyperphosphorylation and reduces neuroinflammatory and amyloid-related pathology.
- Half-life
- Not well established in humans; designed for enhanced metabolic stability
- Administration Routes
- subcutaneous
- Research Status
- Research Chemical
Reported Benefits
- Promotes hippocampal neurogenesis in animal models
- Increases BDNF and downstream synaptic plasticity
- May reduce tau hyperphosphorylation linked to neurodegeneration
- Studied for improvements in learning and memory
- Demonstrates neuroprotective effects under stress in preclinical work
- Investigated as a potential disease-modifying approach for cognitive decline
Potential Side Effects
- Limited human safety data, so the side-effect profile is poorly characterized
- Possible injection-site irritation
- Theoretical headache or fatigue
- Unknown effects with long-term use
Common Dosing
Animal studies have used microgram-per-kilogram dosing; no validated human protocols exist. Reported research-use ranges are typically in the low-microgram daily range. For research use only and not personal medical advice.
The dosing information above is aggregated from research literature and anecdotal community reports for educational purposes only. It is not a recommendation, prescription, or medical advice. Peptides are sold as research chemicals only and are not intended for human use.
Contraindications
- Pregnancy or breastfeeding
- Active malignancy, given effects on neurotrophic and growth pathways
- Lack of human safety data warrants caution in any clinical context
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Neurotrophic peptides incorporating adamantane improve learning and memory, promote neurogenesis and synaptic plasticity in mice
2010
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Rescue of cognitive-aging by administration of a neurogenic and/or neurotrophic compound
2014
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Disease modifying effect of chronic oral treatment with a neurotrophic peptidergic compound in a triple transgenic mouse model of Alzheimer's disease
2014
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Prevention of dendritic and synaptic deficits and cognitive impairment with a neurotrophic compound
2017
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Prevention of Amyloid-β and Tau Pathologies, Associated Neurodegeneration, and Cognitive Deficit by Early Treatment with a Neurotrophic Compound.
2017