This double-blinded, randomized, controlled, pilot trial investigates the effect of a single dose of the GLP-1 receptor agonist, exenatide, on cerebral blood flow velocity in the subacute phase of stroke in humans. The primary endpoint is the mean flow velocity in the middle cerebral arteries measured by transcranial doppler and cortical oxygination measured by near infrared spectroscopy (NIRS). The secondary endpoints are the effects on the peripheral endothelium, hereby: 1) changes in the reactive hyperaemia index measured by EndoPAT2000, 2) changes in the ankle-brachial index, and 3) changes in endothelial/inflammatory biomarkers in the blood. The primary and secondary endpoints are measured before and up till three hours after administration of exenatide.