Common birth control pills called combined oral contraceptives (COC) contain ethinyl-estradiol, a derivative of the estradiol found in the body. COCs are known to raise blood pressure in women taking the pills, but a new study has reported that birth control pills with estradiol have no effect on blood pressure. The work by Grandi and colleagues was reported in the journal Contraception. The study illustrates the important differences between various hormones – synthetic and natural – on our health. For information on the impact of natural hormones on breast cancer and health, see our Questioning aromatase inhibitors page.