P21 vs Semax
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 →Semax
Semax is a synthetic peptide derived from ACTH (adrenocorticotropic hormone). Developed in Russia as a nootropic and neuroprotective agent.
Full details →Side-by-Side Comparison
| Aspect | P21 | Semax |
|---|---|---|
| Mechanism | Inhibits glycogen synthase kinase-3β (GSK-3β) and activates CREB signaling pathway. This promotes BDNF expression, neurogenesis in the hippocampus, and synaptic plasticity. | Enhances BDNF expression, modulates dopamine and serotonin systems, and provides neuroprotective effects. Increases attention, memory formation, and learning. |
| Typical Dosage | Research protocols typically use 1-5mg administered intranasally or subcutaneously. Often used in cycles of 2-4 weeks. | Intranasal: 200-600mcg 2-3 times daily. Higher doses (up to 1mg) used in clinical settings for stroke recovery. |
| Administration | Can be administered intranasally for direct CNS access or subcutaneously. Best used cyclically rather than continuously. | Primarily administered intranasally. N-Acetyl Semax Amidate (NASA) is a modified version with enhanced stability and potency. |
| Side Effects | Limited data. Reported effects include mild headache, temporary brain fog during initial use, and fatigue. | Generally well-tolerated. May cause mild irritability or hair shedding in some users. |
| Best For |
What They Have in Common
Both P21 and Semax are commonly used for: