Semax is derived from the ACTH (4-10) fragment and rapidly upregulates Brain-Derived Neurotrophic Factor (BDNF) and its TrkB receptor in the hippocampus and frontal cortex. This stimulation of BDNF, a crucial protein, enhances neuroplasticity by promoting neuronal growth and repair, synaptic plasticity (learning and memory), and overall cognitive resilience under stress or aging.