P21 vs Humanin
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.
- Humanin is a mitochondria-derived peptide (MDP) encoded in the 16S rRNA region of the mitochondrial genome. It protects neurons and other cells from apoptosis, improves insulin sensitivity, and declines significantly with age. HNG (S14G-Humanin) is a synthetic analog with 1000x greater potency.
- Half-Life
- Not well characterized; likely short, but neurogenic effects persist long after administration
- ~4–8 hours (HNG)
- Admin Route
- SubQ, Intranasal
- SubQ
- Research
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- Typical Dose
- 100–500 mcg
- 2–8 mg
- Frequency
- Once daily
- 3–5 times per week
- 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
- Neuroprotection against amyloid-beta toxicity (Alzheimer's relevance)
- Inhibits cellular apoptosis
- Improves insulin sensitivity
- Reduces cardiovascular risk markers
- Anti-inflammatory effects
- Correlates with longevity in centenarian studies
- Protects against ischemic injury
- Potential cancer cell apoptosis sensitization
- Side Effects
- Generally well tolerated in animal studies
- Limited human clinical data
- Injection site reactions
- Potential mild fatigue at initiation
- Injection site irritation
- Limited human safety data available
- Stacks With
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