Oral contraceptive pills (OCPs) are one of the most widely used reversible contraceptive methods in the United States. Since their introduction in the 1960s, OCPs have been prescribed globally for birth control as well as management of hormonally influenced conditions including menstrual irregularities, menorrhagia, dysmenorrhea, acne, premenstrual syndrome, and hormonal migraines. Despite their therapeutic benefits, the effectiveness of OCPs varies between individuals, and the physiological mechanisms underlying these effects remain incompletely understood. While OCPs are known to influence menstrual bleeding patterns, little is known about their impact on the vasculature of the female reproductive system, specifically the uterine and ovarian arteries. In comparison, intrauterine devices (IUDs) have been studied extensively for their vascular effects. Doppler ultrasound studies, which measure pulsatility index (PI) and resistance index (RI) as indicators of arterial blood flow, generally show no significant vascular changes pre- and post-IUD insertion. However, notable exceptions have been reported between copper and hormonal IUDs. Women experiencing abnormal bleeding with copper IUDs exhibited significant changes in PI and RI; however, another study demonstrated an increased RI in the uterine artery following levonorgestrel IUD (LNG-IUD) placement, potentially explaining its association with reduced menstrual bleeding. Given that copper IUDs tend to increase menstrual bleeding, while LNG-IUDs and OCPs typically reduce it, vascular changes may be an important underlying mechanism. This study aimed to investigate the effects of OCPs on uterine and ovarian artery blood flow using Doppler ultrasound in healthy, nulliparous women and to compare self-reported menstrual symptoms, including pain, cycle regularity, PMS manifestations, and skin changes using a standardized Menstrual Symptom Survey between OCP users and non-users.