Caffeine is a commonly used neurostimulant that also produces cerebral vasoconstriction by antagonizing adenosine receptors. Chronic caffeine use results in an adaptation of the vascular adenosine receptor system presumably to compensate for the vasoconstrictive effects of caffeine.

Does caffeine dilate or constrict blood vessels?

In daily caffeine users, caffeine has less of an effect on brain activation and blood vessel constriction, and caffeine withdrawal is associated with a significant increase in brain blood flow associated with blood vessel dilation.

Why does caffeine narrow your blood vessels?

Blood pressure can go up significantly after caffeine use because it seems to block a hormone our bodies produce to keep our arteries open wide. When caffeine makes the blood vessels in our bodies narrower, this leaves less room for blood flow which, in turn, raises blood pressure.