Semax

Semax is a synthetic heptapeptide analog of the adrenocorticotropic hormone (ACTH) fragment 4-10, developed in Russia as a nootropic and neuroprotective agent. The addition of the Pro-Gly-Pro tripeptide to the C-terminus enhances stability against enzymatic degradation while the core sequence retains the neurotrophic activity of ACTH.

Research has demonstrated Semax produces significant cognitive enhancement effects through multiple mechanisms, including upregulation of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), modulation of dopaminergic and serotonergic transmission, and enhancement of synaptic plasticity. These effects occur without the adrenal-stimulating properties of intact ACTH.

Semax has been extensively studied in models of cerebral ischemia, where it demonstrates neuroprotective effects including reduced infarct volume, decreased neuronal apoptosis, and improved functional recovery. The compound appears to activate endogenous protective mechanisms while suppressing inflammatory cascades in injured brain tissue.

The peptide is typically administered intranasally, taking advantage of the olfactory pathway to achieve direct CNS delivery. This route of administration bypasses the blood-brain barrier and provides rapid onset of central effects, making Semax a valuable tool for studying intranasal peptide delivery to the brain.