Contraceptive applications of estrogen.

Estrogens are a primary component of several contraceptive methods: combined oral contraceptive pills, a combined injectable contraceptive, the combined contraceptive vaginal ring, the combination transdermal contraceptive patch, and combined emergency contraceptive pills. Contraceptive formulations that contain estrogen are referred to as combined contraceptives because they also contain some form of progestin. This article reviews the contraceptive methods containing estrogen, beginning with a discussion of combined oral contraceptive pills. Formulations and clinical management, mechanisms of action, noncontraceptive benefits of use, therapeutic uses in addition to contraception, side effects, contraindications to use, and drug-drug interactions are described. Information follows about the newer combined contraceptive products including the injection, vaginal ring, and patch. Finally, combined emergency contraceptive pills are reviewed. Thorough knowledge of the contraceptive methods containing estrogen enables clinicians to provide expert care for women using these products.