P21 vs Selank
A side-by-side research comparison of P21 and Selank across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | P21 | Selank |
|---|---|---|
| Full name | P21 (CNTF-Derived Tetrapeptide) | Selank (TP-7) |
| Category | Cognitive & Nootropic | Cognitive & Nootropic |
| Status | Research compound | Research compound |
| Mechanism | Mimics CNTF neurogenesis-enhancing portion by increasing BDNF and activating PI3K/Akt. Inhibits LIF signaling to selectively promote neural stem cell proliferation. | Modulates GABA-A allosteric sites, increases BDNF, stabilizes enkephalin degradation, and influences serotonin metabolism. Enhances IL-6 and Th1/Th2 balance. |
| Molecular weight | ~450 Da | 751.9 Da |
| Half-life | 4-6 hours | 3-5 min (IV) / 15-30 min (intranasal) |
| Bioavailability | Moderate (crosses BBB) | Moderate (intranasal) |
| Typical dose | 50-100 mcg/kg | 250-750 mcg per spray dose |
| Frequency | Daily | 2-3x daily |
| Route | Intranasal or Subcutaneous | Intranasal spray |
P21 reported benefits
- Hippocampal neurogenesis
- BDNF increase
- Cognitive enhancement
- BBB penetrant
- No appetite suppression
- Dendritic branching
Selank reported benefits
- Anxiolytic without sedation
- Improved memory/learning
- Cognitive flexibility
- Immune modulation
- BDNF upregulation
- No addiction
Related comparisons
Research and educational reference only. Not medical advice.