Semax is the first domestic nootropic drug of an unexhausted type from the group of neuropeptides. In experimental studies it showed angioprotective, antihypoxic and neurotrophic activity in the doses 100-150 micrograms/kg. A combined clinical-electrophysiologic study revealed its high efficiency in acute ischemic stroke. A clinical trial was performed of immunobiochemical mechanisms of neuroprotective properties of Semax in acute period of ischemic stroke. A retrospective comparative clinicoimmunobiochemical analysis provided objective data on the molecular level on activating influence of Semax on antiinflammatory postischemic reactions in the brain. Shifting neuromediatory balance toward a prevalence of the antiinflammatory agents (interleukin-10, tumor necrosis factor-alpha) over the factors maintaining the inflammation (interleukin-8, C-reactive protein).