The birth control pill is the most popular form of reversible birth control, containing synthetic hormones that prevent pregnancy by inhibiting ovulation, thickening cervical mucus, and thinning the uterine lining. Over 45 years since FDA approval, 18 million US women rely on the pill, which comes in combination and progestin-only varieties. While generally safe and effective, side effects can include nausea, weight gain, and mood changes, and risks include blood clots and certain cancers. User experiences vary, with some noticing lighter periods and others weight gain or no change. Overall, the pill has significantly impacted women's lives by allowing family planning.

1. Birth Control Pills