P21 vs Semax
A side-by-side research comparison of P21 and Semax across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | P21 | Semax |
|---|---|---|
| Full name | P21 (CNTF-Derived Tetrapeptide) | Semax (ACTH 4-10 analog) |
| 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. | Activates MC3/4R, increases BDNF and NGF, modulates dopamine/serotonin, enhances neuronal survival via TrkB, and promotes CREB-mediated neuroplasticity. |
| Molecular weight | ~450 Da | 813.9 Da |
| Half-life | 4-6 hours | 3-5 min (systemic) / extended (intranasal) |
| Bioavailability | Moderate (crosses BBB) | Moderate (intranasal) |
| Typical dose | 50-100 mcg/kg | 200-600 mcg per dose |
| Frequency | Daily | 2-3x daily |
| Route | Intranasal or Subcutaneous | Intranasal drops/spray |
P21 reported benefits
- Hippocampal neurogenesis
- BDNF increase
- Cognitive enhancement
- BBB penetrant
- No appetite suppression
- Dendritic branching
Semax reported benefits
- Enhanced attention/focus
- Memory improvement
- Neuroprotection (stroke)
- BDNF/NGF upregulation
- Improved learning
- Optic nerve support
Related comparisons
Research and educational reference only. Not medical advice.