The birth control pill is highly effective at preventing pregnancy. With perfect use, meaning taking the pill exactly as directed every day without missing any doses, it is more than 99% effective. However, with typical use, which accounts for occasional missed pills or errors, its effectiveness is about 91% to 93%. This means that with typical use, about 7 to 9 out of 100 women may become pregnant within one year of using the pill. Several factors can reduce the pill's effectiveness, including forgetting to take a pill on time, vomiting or diarrhea shortly after taking it, some medications interfering with absorption, or improper storage of the pills. To maximize effectiveness, it is important to take the pill as consistently and correctly as possible. While the pill provides no protection against sexually transmitted infections (STIs), it can also offer benefits such as regulation of menstrual cycles, reduced menstrual symptoms, and decreased risk of certain cancers like endometrial and ovarian cancer. In summary:
- Perfect use effectiveness: >99%
- Typical use effectiveness: 91-93%
- Factors lowering effectiveness: missed pills, vomiting, diarrhea, interfering medications
- No STI protection, so condoms are recommended for that purpose
- Additional health benefits include cycle regulation and cancer risk reduction.
