P21 vs Dihexa
Side-by-side comparison of key properties, dosing, and research.
- Summary
- P21 is a synthetic peptide derived from CNTF (ciliary neurotrophic factor) that promotes hippocampal neurogenesis, enhances memory and spatial learning, and may reduce amyloid-beta pathology. It is used as a neurogenic and cognitive enhancer with potential anti-Alzheimer's applications.
- Dihexa is a potent experimental oligopeptide derived from angiotensin IV that dramatically enhances synaptogenesis. Preclinical research shows cognitive enhancement orders of magnitude more potent than BDNF — it is considered one of the most powerful nootropic compounds in research, but has very limited human safety data.
- Half-Life
- Not well characterized; likely short, but neurogenic effects persist long after administration
- Unknown (limited pharmacokinetic data)
- Admin Route
- SubQ, Intranasal
- Oral, SubQ, Topical
- Research
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- Typical Dose
- 100–500 mcg
- 5–10 mg
- Frequency
- Once daily
- Daily
- Key Benefits
- Promotes hippocampal neurogenesis
- Enhances spatial memory and learning
- Increases BDNF expression
- Reduces amyloid-beta plaque formation (animal models)
- Anti-tau pathology potential
- Cognitive enhancement without stimulant effects
- Potential therapeutic for Alzheimer's and cognitive aging
- Dramatically increases synapse formation (potentially 10 million× more potent than BDNF in animal models)
- Enhances memory and learning
- May reverse cognitive decline
- Improves neuroplasticity and executive function
- Long-lasting cognitive benefits from short courses
- Potential therapeutic agent for Alzheimer's
- Side Effects
- Generally well tolerated in animal studies
- Limited human clinical data
- Injection site reactions
- Potential mild fatigue at initiation
- Headache
- Irritability
- Brain fog during washout period
- Unknown long-term effects (insufficient data)
- Stacks With
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