Semax derives from adrenocorticotropic hormone, specifically the 4-10 fragment, which is the region of the parent hormone associated with central nervous system activity rather than steroidogenic activity. Attaching Pro-Gly-Pro at the C-terminus slows enzymatic degradation substantially. The result is a heptapeptide, MEHFPGP, that remains measurable long enough to characterise in a laboratory setting while retaining the fragment's signalling profile.

The pathway that dominates the published literature is neurotrophic factor expression. Preclinical studies examine the compound's influence on brain-derived neurotrophic factor and nerve growth factor transcription in hippocampal and cortical tissue, along with the downstream tropomyosin receptor kinase signalling those factors drive. Because the effect is transcriptional rather than direct receptor agonism, the experimental methods are typically expression assays and time-course work rather than binding studies.

Secondary research contexts include monoaminergic modulation, where the compound features in studies of dopaminergic and serotonergic turnover, and hypoxia and ischaemia models, where it appears in work on antioxidant enzyme expression and cerebral perfusion in animal subjects. Much of the foundational literature is Russian-language and predates Western replication, which is itself a stated reason the compound continues to attract independent laboratory investigation. No therapeutic, diagnostic, or clinical conclusion is drawn from any study referenced above, and none should be inferred.