P21

P21 is a synthetic tetrapeptide - only four amino acids, derived from CNTF (Ciliary Neurotrophic Factor), an endogenous neurotrophin. Small enough to cross the blood-brain barrier and act directly in the brain.

In preclinical studies P21 is among the most potent known neurogenesis enhancers - it stimulates the formation of new neurons in the hippocampus, the brain region for learning and memory.

P21 increases BDNF (Brain-Derived Neurotrophic Factor) expression and reduces pathological tau phosphorylation. BDNF acts like fertilizer on synapses - existing connections strengthen, new ones form more easily. The tau effect is interesting in the Alzheimer's context.

Additionally it stimulates adult neurogenesis in the hippocampus - one of the few brain regions where new neurons form at all in the adult brain.

P21 is injected subcutaneously into the abdomen area, about 2 times per week. The lyophilized powder in the vial is reconstituted with bacteriostatic water beforehand.

• Subcutaneous, thin insulin needle.
• 2x per week is enough thanks to the sustained BDNF effect.
• Ideally in the morning - P21 is mildly activating.

P21 was developed at the New York State Institute for Basic Research and tested in several preclinical studies:

• Kazim et al. 2014: improved learning and memory in Alzheimer's mouse models.
• Khatoon et al. 2015: reduction of tau phosphorylation plus boost of adult neurogenesis.
• Bolognin et al. 2014: increased BDNF expression and neurogenesis promotion in the hippocampus.

Robust human data is lacking so far - everything is preclinical and small.

• Occasional local irritation at the injection site.
• Some users report mild drive or sleep shifts in the first days.
• No known serious side effects from preclinical studies.

Store lyophilized powder dry at normal room temperature (around 20 to 25 degrees), protected from light. After reconstitution, refrigerate - stable for at least 8 to 10 weeks with barely any loss, in practice considerably longer.