What it is
Semax is a peptide made of 7 amino acids. It is made in a lab. It copies a small piece of ACTH, a stress hormone. That piece of ACTH is linked to memory and attention. Three extra amino acids were added to the end so the body breaks it down slower. Full ACTH tells the adrenal glands to release cortisol. Semax does not. Scientists at the Russian Academy of Sciences built it. It has been an approved prescription drug in Russia since 1994, sold as a nasal spray. Other names: ACTH 4-10 analog, Semax acetate.
What researchers study it for
- Brain cell protection after stroke in rats and people
- BDNF and NGF, two proteins that keep brain cells alive
- Attention and memory in animals
- Anxiety in animal tests
- Serotonin and dopamine activity in the brain
What the studies found
1. It raised BDNF in several parts of the rat brain.
BDNF is a protein that keeps brain cells alive and helps them form new connections. After one dose, BDNF rose in the hippocampus, which handles memory, and in the frontal cortex, which handles planning and attention. The rise lasted 24 to 48 hours. This is the main reason researchers think Semax affects memory.
2. Stroke patients got function back faster.
A 1997 Russian study gave Semax to 30 stroke patients and compared them to 80 patients on standard care. Treated patients regained lost function faster on neurological rating scales and on brain wave tests. The study was small and was not repeated in Western trials.
3. It turned down inflammation genes in rat brains after stroke.
After a stroke, immune cells rush in and cause a second wave of damage. This 2017 study measured gene activity in rat brains after a stroke. Semax lowered activity in genes that drive inflammation and raised activity in genes that drive repair. Less inflammation means less brain tissue is lost in the days after the stroke.
4. It lowered cell death proteins in rat brains after stroke.
A 2021 study measured proteins in rat brains 24 hours after a stroke. Semax lowered three proteins that push cells to die or swell. It raised one protein that drives recovery. This matches the gene study above at the protein level.
5. It raised serotonin activity in rats.
Semax raised a serotonin breakdown product in the striatum by about 25 percent in tissue and up to 180 percent outside cells. That means more serotonin was being used. Semax alone did not change dopamine. When given before amphetamine, it made the amphetamine dopamine spike much bigger. So Semax is not a stimulant on its own, but it does change how the brain handles these two chemicals.
6. It leaves the blood in minutes but stays in the brain for a day.
Radioactive-tagged Semax was given to rats through the nose. It reached the brain within 30 minutes and was still there after 24 hours. In the blood, half of it was gone in 2 to 3 minutes. The nose route sends it straight to the brain along the smell nerves, which is why nasal spray is the form used in Russia.
How much research exists
Many animal and cell studies, most published in international journals. Human trials exist but almost all are Russian-language and small. The FDA and the European Medicines Agency have never reviewed Semax.
Facts
- Formula: C37H51N9O10S
- Weight: 813.9 g/mol
- CAS number: 80714-61-0
- Sequence: Met-Glu-His-Phe-Pro-Gly-Pro
- Time in the blood: 2 to 3 minutes. Brain effects last much longer.
- Storage: freeze the dry powder. Keep mixed solution in the fridge.
Legal status
Approved as a prescription drug in Russia and Ukraine. Not approved by the FDA or any Western agency for human use.
For research use only. Not for human use. Nothing here is medical advice.