The First Birth Control Pill Is Approved

In May 1960, the United States Food and Drug Administration approved the first oral medication intended to prevent pregnancy, clearing a ten-milligram tablet called Enovid for contraceptive use. Developed by the pharmaceutical company G. D. Searle, the formulation combined two synthetic hormones: the progestin noretynodrel and the estrogen mestranol. The agency had already sanctioned the same tablet in 1957 for the treatment of menstrual disorders, a designation under which hundreds of thousands of American women had already taken it before it secured official authorization as birth control.

The medication functioned by altering hormonal signals within the female reproductive cycle. In a typical menstrual cycle, hormones released by the pituitary gland prompt ovarian follicles to mature and release an egg. By elevating circulating levels of synthetic estrogen and progestin, the daily tablet suppressed the release of follicle-stimulating hormone and luteinizing hormone through negative feedback mechanisms. This hormonal intervention prevented follicular development and eliminated mid-cycle ovulation entirely. The progestin component additionally thickened cervical mucus, creating a physical barrier that impeded the movement of sperm into the upper reproductive tract.