• Initial reports indicated that caffeine has a pressor effect, raising the possibility that it might contribute to hypertension. However, further studies have demonstrated that caffeine does not produce a persistent increase in blood pressure. Individuals who do not regularly consume caffeine may experience a slight increase in blood pressure when they are exposed to caffeine, but tolerance develops rapidly and blood pressure returns to baseline.
(Arch Intern Med 1988;148:1189-1193)
Myers MG. Effects of Caffeine on Blood Pressure. Arch Intern Med. 1988;148(5):1189-1193. doi:10.1001/archinte.1988.00380050193027