P21 vs Thymulin
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.
- Thymulin is a nonapeptide hormone produced exclusively by the thymic epithelium. It requires zinc for biological activity and plays a critical role in T-lymphocyte maturation, differentiation, and immune regulation. Thymulin levels decline dramatically with age, contributing to immunosenescence.
- Half-Life
- Not well characterized; likely short, but neurogenic effects persist long after administration
- ~30 minutes active half-life
- Admin Route
- SubQ, Intranasal
- SubQ
- Research
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- Typical Dose
- 100–500 mcg
- 20-30 mcg
- Frequency
- Once daily
- 10 days per month (Khavinson protocol)
- 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
- Enhances T-cell maturation and differentiation
- Boosts NK cell cytotoxic activity
- Reduces inflammatory cytokine production (TNF-α, IL-1)
- Anti-nociceptive (pain-reducing) properties
- Restores age-related immune decline
- Anti-inflammatory via serotonin pathway modulation
- Side Effects
- Generally well tolerated in animal studies
- Limited human clinical data
- Injection site reactions
- Potential mild fatigue at initiation
- Injection site reactions
- Mild fatigue initially as immune system activates
- Stacks With
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