P21 vs Substance P
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 →Substance P
Substance P is an 11-amino acid neuropeptide involved in pain transmission, inflammation, and various neurological processes. While not used therapeutically itself, understanding it is crucial for pain research.
Full details →Side-by-Side Comparison
| Aspect | P21 | Substance P |
|---|---|---|
| Mechanism | Inhibits glycogen synthase kinase-3β (GSK-3β) and activates CREB signaling pathway. This promotes BDNF expression, neurogenesis in the hippocampus, and synaptic plasticity. | Binds primarily to NK1 receptors to transmit pain signals from peripheral nerves to the CNS. Also promotes inflammation, causes vasodilation, and stimulates immune cells. |
| Typical Dosage | Research protocols typically use 1-5mg administered intranasally or subcutaneously. Often used in cycles of 2-4 weeks. | Not used as a therapeutic agent. NK1 receptor antagonists (blocking Substance P) are used clinically for chemotherapy-induced nausea. |
| Administration | Can be administered intranasally for direct CNS access or subcutaneously. Best used cyclically rather than continuously. | Research compound only. Therapeutic applications focus on blocking rather than administering Substance P. |
| Side Effects | Limited data. Reported effects include mild headache, temporary brain fog during initial use, and fatigue. | Administration would cause pain, inflammation, and neurogenic responses. Not given therapeutically. |
| Best For |
What They Have in Common
Both P21 and Substance P are commonly used for: