Neurotransmitters are the key factors in ameliorating the symptoms of nervous system diseases. Stroke/cerebral ischemia has been proven to be caused by the excess release of excitatory amino acid glutamate in the brain, and the inhibitory neurotransmitter γ-aminobutyric acid (GABA) is considered to be the best choice to counteract the action of glutamate. Here, we show that GABA conjugated to a cytoplasmic transduction peptide (YGRRARRRRRR) by means of custom chemical synthesis could penetrate through the blood-brain barrier, increasing the GABA level in the plasma of rats and mice, which, as a result, display a state of calmness and somnolence.