“…Most studies found that women using oral contraceptives have higher BPs than nonusers, but the magnitude of the differences vary, possibly reflecting differences in the populations studied and variations in the doses and types of agents used [36,37,38•,39-43,44••]. When evaluated, the effect of oral contraceptives on BP is more consistently related to estrogens than to progestational agents, whereas reports of the effects of progestogens on BP differ [40,41,43,45,46]. In some studies, progestogens reportedly have no effect on BP [43,46], although The Oral Contraceptive Study of the Royal College of General Practitioners, a prospective study, found that the incidence of hypertension increased with the duration of use and with increasing strength of the progestin [47].…”