Semax

Semax is a synthetic heptapeptide: the ACTH(4–7) fragment Met-Glu-His-Phe joined to a Pro-Gly-Pro tail. That tail is the design point. The bare ACTH fragment is cleared by peptidases very quickly, and the added tripeptide extension is what made the molecule stable enough to study at all.

It carries none of the corticotropic activity of full adrenocorticotropic hormone — the fragment was chosen specifically for what it leaves out. Semax came out of Russian peptide-design work in the 1980s, and the bulk of the primary literature is still Russian-language. It ships as a lyophilised powder in a sealed vial, reconstituted in the laboratory.

Semax is studied within the neuropeptide literature, largely in rodent models and cell culture.

Areas investigators have examined:

• Expression of brain-derived neurotrophic factor and nerve growth factor in rodent hippocampus
• Dopaminergic and serotonergic system activity in animal models
• Gene-expression changes in models of experimental cerebral ischaemia
• Antioxidant and inflammatory markers within those same ischaemia models
• Behavioural endpoints such as maze performance in rodents

Much of the primary work is published in Russian-language journals and has seen limited independent replication elsewhere, which is worth weighing when reading the literature. Semax is supplied for laboratory research only.