Cognitive / Nootropic
P21
Peptide 21 · CNTF mimetic
What it is
P21 is an 11-amino-acid peptide developed at the Lankenau Institute for Medical Research. It mimics the active region of CNTF (ciliary neurotrophic factor), which promotes neurogenesis and neuroprotection. Theoretical longevity and cognitive enhancement tool.
How it works
Activates CNTF-like receptors to stimulate neurogenesis (new neuron formation), particularly in the hippocampus. Reduces tau hyperphosphorylation (the protein change implicated in Alzheimer's). Crosses the blood-brain barrier.
Benefits
- Theoretical neurogenesis
- Memory enhancement
- Possible Alzheimer's protective effects
- Mood lift in some users
Timeline
- Week 2–4
- Subtle cognitive shifts.
- Month 2–3
- Cumulative neurogenesis effects (theoretical).
Dosing & titration
Standard dose100–500 mcg subQ daily
Cycle length8–12 weeks
When to titrate upVery limited human data. Start at low end.
Side effects & risks
- Generally well tolerated in early reports
- Limited human safety data
- Mild injection site reactions
Highly experimental. Most data is preclinical/animal. Use with caution.
Typical price
$100–$200/moLimited availability.
Studies
- Search PubMed for peptide P21 CNTF — PubMed searchLive PubMed search
Educational reference only. Not medical advice.