P21
Neurogenesis (CNTF-derived)
A CNTF-derived neurogenic peptide built for hippocampal growth.
Also sold as
Research chemical vendors can't legally label products with the real name, so P21 often appears under coded SKUs. If you're shopping and see any of these, it's the same compound:
- P21
- P-21
Codes shown are for identification only.
Your draw
What it actually is
P21 is a small peptide derived from ciliary neurotrophic factor (CNTF). It mimics CNTF's neurogenic signaling while being small enough to cross the blood brain barrier, and it has been studied for adult hippocampal neurogenesis and tau pathology in animal models.
1mg per dose, 5 days on and 2 off, 8 week cycles. Animal data only, no human trials.
Why people use it
- Memory and learning support through neurogenesis
- Interest in tau and neurodegeneration research
- Stacked with Semax or Selank in nootropic protocols
Educational only · Not a vendor claim
How it works
A CNTF-derived peptide small enough to cross the blood brain barrier, mimicking CNTF's neurogenic signaling in the hippocampus.
Health benefits
- Hippocampal neurogenesis
- Memory and learning support
- Studied against tau pathology
- Neuroprotection
What you'll feel
- Gradual memory improvement over weeks
- Better mood in some users
- No acute stimulation
Pros
- Novel neurogenesis mechanism
- Pairs with Semax/Selank
- Low dose volume
Cons
- Animal data only
- No human trials
- Effects are slow and hard to self-assess
Side effects to know
- Headache
- Fatigue
- Injection site irritation
Best suited for
Educational summary · Not medical advice · Discuss with a qualified clinician
Typical timeline
General pattern for the Neuro Cognition category. Individual response varies.
- Day 1–3Effect can be felt within hours: calmer focus (Selank), sharper attention (Semax), or deeper sleep (DSIP).
- Weeks 1–4Consistent daily benefits. Mood and cognitive stamina improve without stimulant crash.
- Post-cycleTake a break to avoid tolerance. Most users cycle 8 on / 8 off.
The reconstitution math
- 1Reconstitute the 10 mg vial with 2 mL of bacteriostatic water. Tilt — don't shake.
- 2Concentration becomes 5,000 mcg/mL (5 mg/mL).
- 3For a 1 mg dose, draw 0.200 mL — that's 20 units on a 1 mL insulin syringe.
- 4One vial gives you approximately 10 doses.
Reminder: 100 units on an insulin syringe = 1 mL. Always start at half the listed dose for the first week and rotate injection sites between arms, legs, abdomen, and glutes.
Dose logging is available for signed-in users. Track today's dose and notes for P21.
Use code ANYPEPTIDES15 for 15% off your order.
Discount may end or change without notice.
Keep going from here
Everything on the site that connects to P21: comparable compounds, the exact math for this vial, and the tools to run the cycle.
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Tools for this protocol
Prefilled with 10 mg, 2 mL BAC water, and a 1 mg dose.
Printable units-to-micrograms lookup for every common vial and water volume.
Add P21 to a protocol with schedule, dosing, and a shopping list.
Log each dose so you can tie effects and side effects to real dates.
Put P21 next to two other peptides on dosing and goals.
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