Semax is a lab-made chain of seven amino acids, built from a piece of the hormone ACTH. Russia approves it as nose drops for stroke and some thinking problems. Most of the evidence is Russian trials and animal studies, and the FDA has not approved it.
Why scientists study it
- It is a piece of the hormone ACTH, called ACTH(4-7), with a Pro-Gly-Pro tail added. The tail lets it last about 24 minutes in blood plasma. The natural fragment ACTH(4-10) lasts seconds.
- In rodents and in cells in a dish, it raised the nerve growth proteins BDNF and NGF and protected nerve cells.
- Its approval in Russia rests on Russian trials in recovery from ischemic stroke and in cerebrovascular disease.
Three studies to know
2018 · Zh Nevrol Psikhiatr
Gusev and colleagues tested Semax at different stages of ischemic stroke. They reported that it helped rehabilitation results. Read the paper
2006 · J Neurochem
Dolotov and colleagues found that Semax binds to specific sites in the basal forebrain of rats and raises BDNF protein there. Read the paper
2017 · Mol Genet Genomics
Medvedeva and colleagues studied rats with ischemic brain injury. Semax changed the activity of genes that run the immune response. Read the paper
Safety and legal status
- Russian clinics use it as nose drops. No large Western trial has tested it.
- Only Russia approves it. The MHRA, FDA and EMA have not. The 2026 WADA Prohibited List does not name it, but the list also has open-ended classes.
- For laboratory research use only. It is supplied as a research peptide and is not a licensed medicine.