P21 vs Pal-AHK
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.
- Pal-AHK is the palmitoylated form of the AHK-Cu copper tripeptide, created by attaching a palmitic acid chain to enhance skin penetration and lipid bilayer affinity. The palmitoyl modification significantly improves dermal bioavailability compared to unmodified AHK, making it particularly effective in anti-aging and hair growth formulations.
- Half-Life
- Not well characterized; likely short, but neurogenic effects persist long after administration
- Extended (lipid depot effect in stratum corneum)
- Admin Route
- SubQ, Intranasal
- Topical
- Research
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- Typical Dose
- 100–500 mcg
- 0.01–0.05% in formulation
- Frequency
- Once daily
- Once or twice 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
- Enhanced skin penetration vs. unmodified AHK-Cu
- Stimulates dermal collagen and elastin production
- Promotes hair follicle anagen phase
- Antioxidant and wound healing activity
- Firming and plumping effect on aging skin
- Improved bioavailability via lipid bilayer incorporation
- Side Effects
- Generally well tolerated in animal studies
- Limited human clinical data
- Injection site reactions
- Potential mild fatigue at initiation
- Generally well-tolerated
- Mild irritation at high concentrations in sensitive skin
- Possible comedogenicity at very high palmitate concentrations (formulation-dependent)
- Stacks With
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