Side by side
P21 vs Semax
Both are discussed for cognition & mood. What this site records about each, side by side. Every figure is on the compound's own page with the source it came from.
| P21 | Semax | |
|---|---|---|
| What it is | A tetrapeptide derived from a nerve growth factor, engineered to reach the brain. Real academic research, entirely in mice. | A seven-amino-acid peptide developed in Russia and approved there for stroke and cognitive indications. It holds no approval elsewhere and is used nasally rather than injected. |
| EvidenceHow much human evidence exists, not how well it works. | Preclinical | Approved for another indication |
| Regulatory statusReviewed 2026-08-18 | Not approved anywhere and never studied in a human trial. Developed in academic research with associated patents; no clinical programme has reported. Sold only as a research chemical. | Approved and clinically used in Russia, where it appears on the essential medicines list. Not approved in the United States, the EU or the UK, and material sold in those markets is an unapproved substance with no manufacturing standard behind it. |
| Routes | Subcutaneous, Nasal | Nasal |
| Half-life | Not recorded | 0.5 hours |
| Cheapest per mgVials only, read from vendors' own listings and dated on the price index. | $1.40/mg | $0.97/mg |
| Median per mg | $12.75/mg | $3.91/mg |
| Vendors with a price | 9 | 47 |
| Storage once mixed | Refrigerated at 2–8 °C. Nasal solutions are handled more than injectables and are correspondingly easier to contaminate. | Refrigerated at 2–8 °C. Nasal solutions are entered repeatedly, so bacteriostatic water rather than sterile water matters here. |
Compare two other compounds · The full price index
This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on BioAlmanac is medical advice. Nothing here ranks these two against each other. A table can show that one has more human evidence behind it or costs less per milligram; neither of those is a recommendation, and the right comparison for any person is one their doctor makes with them.