Types of oral contraceptives, their mode of action, choice of dosage, side effects, and contraindications are summarized for the general clinician. A 50 mcg dosage of estrogen in a combination formula appears to be the minimum dose necessary for consistent protection from pregnancy although some compounds with less estrogen but a more powerful progestin appear to provide good protection. These lower dose estrogen formulations may be advised if estrogen-related symptoms such as nausea or breast soreness are encountered. In amenorrheao r symptoms of estrogen deprivation 80-100 mcgs of estrogen may be required. Although there is a risk of thromboembolic disease, hypertension, carbohydrate and lipid metabolic effects, gallbladder disease, hepatoma, and possible post-pill amenorrhea, these problems can be minimized by careful screening of patients. Benefits include decreased incidence of ovarian cysts, benign breast neoplasia, menstrual disorders, premenstrual syndrome, iron deficiency anemia, sebaceous cysts, and acne (due to decreased sebum production with estrogen adminsitration). Patients need to be reminded that the morbidity and mortality associated with pregnancy exceed that attributed to oral contraceptives.