P-21
Synthetic ciliary neurotrophic factor (CNTF)-mimetic peptide. Targets neurogenesis. Pre-clinical / early research compound.
P-21: Synthetic ciliary neurotrophic factor (CNTF)-mimetic peptide. Targets neurogenesis. Pre-clinical / early research compound. P-21 is a synthetic peptide that mimics CNTF (ciliary neurotrophic factor).
P-21 is a synthetic peptide that mimics CNTF (ciliary neurotrophic factor). Targets neurogenesis pathways. Pre-clinical research compound, no human dosing data exists.
Who it's for
- →Researchers studying CNTF pathways
- →Cognitive-decline research contexts
- →Educational reference, limited human data
What to expect
- Week 1
Subtle. Animal-model markers begin shifting.
- Week 4
Cycle endpoint in most pre-clinical protocols.
- Week 8
No human long term data.
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How it works (mechanism)
Synthetic peptide that mimics CNTF (ciliary neurotrophic factor) action on neurogenesis pathways. Pre-clinical only, mechanism partially characterized.
Dosing protocol
Stacks well with
Side effects
When NOT to use
- ⚠Pregnancy / nursing
- ⚠Anyone risk-averse to pre-clinical compounds
Common mistakes
- • Treating it as a defined nootropic protocol
- • Long cycles without safety data
What it actually is
P021 — usually written P021 or peptide 021 in the literature, and sold as P-21 — is a synthetic peptide derived from a ciliary neurotrophic factor sequence, further modified with an adamantylated group to improve stability and brain penetration. It is studied for stimulating neurogenesis and for inhibiting a pathway involved in tau pathology. It is an early research compound. Its entry carries a specific warning about its own evidence record, because the name collides badly with unrelated biology.
Ciliary neurotrophic factor supports neuronal survival and promotes neurogenesis in the hippocampus. The full protein is a poor drug and produced significant side effects in trials for other conditions, so P021 was built from an active fragment with chemical modifications for stability and brain entry. Preclinical work reports both increased neurogenesis and reduced tau hyperphosphorylation, which is a broader mechanism than neurogenesis alone. All of it is preclinical.
Forms, and which is which
Animal-model dosing is per kilogram. No standardised human protocol exists.
Verdict: The honest description of where this is.
Buyer reconstitutes at a dose extrapolated from animal work.
Verdict: Unverified material, invented dose.
Combines untested compounds, making anything observed unattributable.
Verdict: Several unknowns at once.
Exercise in particular has real evidence for hippocampal neurogenesis and cognitive outcomes.
Verdict: The comparison worth making.
What it is claimed to do, graded
Reported in animal models, alongside effects on tau phosphorylation. Preclinical throughout, and the models are mostly transgenic Alzheimer mice rather than healthy animals.
No human trial of this compound.
No human safety data. The parent growth factor caused significant side effects in trials for other conditions, which is part of why a peptide mimetic was pursued.
Read any citation count under this name with suspicion. The compound is P021; the string P-21 collides with p21 the cell-cycle protein, and with RAS-p21 and PCNA work — literature about entirely different molecules. That is why the site index returns it ungraded, and why the apparent paper count is a search artefact rather than evidence.
Grades describe how much human evidence exists for that specific claim, not whether it will work for you or whether it is safe.
Pros and cons
- • Targets a real mechanism — CNTF and hippocampal neurogenesis are legitimate neuroscience
- • Designed specifically to avoid the problems that limited the parent growth factor
- • Reported to be well tolerated in animal models
- • No human trials of the compound
- • Its evidence record is contaminated by a name collision with unrelated cell-cycle biology, which inflates any casual citation count
- • No human dosing protocol
- • The parent growth factor had significant side effects in human trials
- • Research-chemical supply with unverified identity
When to stop
- • Mood or psychiatric change
- • Headache that persists
- • Injection-site reaction that spreads
- • Any new cancer diagnosis
Interactions
Compounds growth signalling with no established benefit.
A neurotrophic and growth signal in a body with a tumour is unstudied.
No interaction data for a compound acting on neurogenesis.
Stacking untested compounds makes any effect unattributable.
There is no human interaction literature for this compound.
Is this for you?
- • Laboratory research. There is no human context, and its apparent evidence base is largely a naming artefact
- • You have active cancer
- • You are pregnant or nursing
- • You saw a large citation count under this name and took it as evidence — it is a different molecule's literature
- • You want a dose with any basis
The one number
Sources for the claims above
- Peptides that block RAS-p21 protein-induced cell transformation — an example of the unrelated literature this name collides with
- Growth factors and P21 activation — further unrelated p21 literature
- Listed among peptides used outside approved indications
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Tracked alongside P-21
Same goal, different aisle — each graded on its own evidence in the Pepdex catalog.
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