P21 vs Selank
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
P21
P21 is a synthetic peptide derived from Cerebrolysin, specifically designed to mimic the neurotrophic effects of the parent compound. It promotes neurogenesis and has shown cognitive-enhancing properties in research.
Full details →Selank
Selank is a synthetic peptide derived from the naturally occurring immunomodulatory peptide tuftsin. Developed in Russia for anxiety and cognitive enhancement.
Full details →Side-by-Side Comparison
| Aspect | P21 | Selank |
|---|---|---|
| Mechanism | Inhibits glycogen synthase kinase-3β (GSK-3β) and activates CREB signaling pathway. This promotes BDNF expression, neurogenesis in the hippocampus, and synaptic plasticity. | Modulates the expression of brain-derived neurotrophic factor (BDNF) and affects serotonin and norepinephrine systems. Has immunomodulatory and anxiolytic properties. |
| Typical Dosage | Research protocols typically use 1-5mg administered intranasally or subcutaneously. Often used in cycles of 2-4 weeks. | Intranasal administration: 250-500mcg 2-3 times daily. Subcutaneous: 250-500mcg daily. |
| Administration | Can be administered intranasally for direct CNS access or subcutaneously. Best used cyclically rather than continuously. | Most commonly administered intranasally for cognitive effects. Can also be injected subcutaneously. |
| Side Effects | Limited data. Reported effects include mild headache, temporary brain fog during initial use, and fatigue. | Generally well-tolerated. Some users report mild fatigue or nasal irritation with intranasal use. |
| Best For |
What They Have in Common
Both P21 and Selank are commonly used for: