Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide analog of adrenocorticotropic hormone (ACTH) fragment 4-10, engineered with a C-terminal Pro-Gly-Pro tripeptide extension. This unique modification confers remarkable metabolic stability, enhanced blood-brain barrier permeability, and neuroprotective properties while eliminating the corticosteroid-releasing effects of ACTH. Semax functions as a potent nootropic and neuroprotective agent through modulation of brain-derived neurotrophic factor (BDNF) expression, neurotransmitter systems, and cerebral blood flow, making it an invaluable tool for neuroscience research.