P21 dosage and protocol
Synthetic derivative of Cerebrolysin designed for enhanced neurogenesis and synaptogenesis. Supports cognitive function, learning, and neurological recovery.
- Vial size: 5 mg
- Reconstitution: 2 mL bacteriostatic water
- Concentration: 2.5mg/mL
- Administration: subcutaneous
Research areas
- Cognitive Enhancement
- Neurogenesis
- Synaptogenesis
- Neuroprotection
- Learning
- Memory
- TBI Recovery
Quick start
- Reconstitute: Add 2.0 mL bacteriostatic water to the 5 mg vial for 2.5 mg/mL
- Typical dose: 2-5 mg once daily for 4-8 weeks, then a 2-4 week break
- Easy measuring: At 2.5 mg/mL, 1 unit = 0.01 mL = 25 mcg on a U-100 syringe; 2 mg is 80 units and 5 mg is 200 units (2 mL)
- Storage: Refrigerate after mixing, protect from light, use within 2-4 weeks
Dosing protocol
| Phase | Dose | Frequency | Volume |
|---|---|---|---|
| Standard | 2-5mg | daily | 0.8-2.0 |
| Loading | 5mg | daily | 2.0 |
| Cycle Break | 0 | off | 0 |
How it works
P21 (also written P021) is a small synthetic peptidomimetic derived from an active region of ciliary neurotrophic factor (CNTF), developed by researchers working on neurotrophic approaches to Alzheimer's disease. It is often described as related to Cerebrolysin, but it is a defined, modified fragment with an adamantane group added to improve stability and blood-brain barrier penetration. Its proposed mechanism involves increasing brain-derived neurotrophic factor (BDNF) expression and inhibiting leukaemia inhibitory factor (LIF) signalling, which together are thought to promote neurogenesis in the hippocampus and synapse formation. In rodent studies, including transgenic Alzheimer's disease mouse models and aged rats, P021 increased markers of neurogenesis and synaptic density, reduced tau hyperphosphorylation and improved performance in learning and memory tasks. Most of these studies administered the compound orally, mixed into food, over weeks to months. No published human clinical trials are available. Its benefits for cognition, learning or neurological recovery in people are therefore unproven, and injectable dosing used in research protocols is not based on human pharmacokinetic data.
Reconstitution steps
- Draw 2.0 mL bacteriostatic water with a sterile syringe
- Inject slowly down the vial wall; avoid foaming
- Gently swirl/roll until dissolved (do not shake)
- Label with reconstitution date and refrigerate at 2–8°C, protected from light; use within 30 days
Storage
Store reconstituted peptide refrigerated. Protect from light. Typical stability: 2-4 weeks when refrigerated.
Important notes
- Derived from CNTF (Ciliary Neurotrophic Factor)
- More targeted approach compared to Cerebrolysin
- Can be administered subcutaneously or intranasally
- Morning administration typically preferred
- Effects may persist after discontinuation
- Avoid with active cancer, pregnancy, or seizure history
Supplies
- Bacteriostatic water
- Insulin syringes
- Alcohol swabs
- Optional: nasal spray bottle