"The original class of birth control pills contained a high dosage of both estrogen and progestin, which led to a variety of side effects, including blurred vision, nausea, cramping, irregular menstrual bleeding, headaches, and possibly breast cancer. Beginning in about 1975, the manufacturers of the Pill, in reaction to adverse publicity generated about the severe side effects caused by the high-dosage pills, steadily decreased the content of estrogen and progestin in their products."