Thymalin vs P21
Side-by-side comparison of key properties, dosing, and research.
- Summary
- Thymalin is a polypeptide complex isolated from calf thymus glands (developed by the Russian Gerontology Institute), shown to restore immune function, extend lifespan, and reverse thymic involution. Clinical studies demonstrate improved immune parameters and up to 40% reduction in mortality in elderly patients.
- 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.
- Half-Life
- Not well characterized as a complex extract; individual peptides have varying kinetics
- Not well characterized; likely short, but neurogenic effects persist long after administration
- Admin Route
- SubQ, IM
- SubQ, Intranasal
- Research
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- Typical Dose
- 10 mg IM or SC daily
- 100–500 mcg
- Frequency
- Once daily
- Once daily
- Key Benefits
- Restores thymic function and T-cell immunity
- Extends healthy lifespan (documented in long-term studies)
- Reduces infectious disease incidence in elderly
- Normalizes immune parameters in immunodeficiency
- Anti-tumor immune surveillance
- Improves vaccine response in elderly
- Reduces cardiovascular mortality (40% in landmark Russian study)
- Normalizes neuroendocrine function
- 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
- Side Effects
- Very well tolerated in decades of Russian clinical use
- Mild injection site reactions
- Rare: mild allergic reaction (natural extract)
- Transient flu-like symptoms on initiation (immune activation)
- Generally well tolerated in animal studies
- Limited human clinical data
- Injection site reactions
- Potential mild fatigue at initiation
- Stacks With
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