In a new study, 718 women used a fertility tracking app called DOT as their main form of birth control for 13 menstrual cycles. The app had a typical-use failure rate of five percent, making it just as effective as the pill and vaginal rings, which fail about seven percent of the time.
After you answer a few questions about your period, the app draws from relevant research to determine your pregnancy risk for each day of your cycle, explains Victoria Jennings, Ph.D., the study’s principal investigator and the director of the Institute for Reproductive Health at Georgetown University in Washington, DC. On high-risk days (usually in the five days before and the 24 hours after you ovulate) you’ll get a pop-up reminding you to either use protection or skip sex.
“For most women, DOT is effective right away,” Jennings says. At first, your so-called “fertile windows” will be relatively long, but they’ll become more tailored to your personal cycle as you enter more data. The app won’t work for women with cycles shorter than 20 days or longer than 40.
The bottom line:
Apps are safe, effective alternatives to hormonal birth control. Natural Cycles and Lady Cycle ask for more personal information (your lowest body temperature while at rest, for one) but can work just as well as DOT, Jennings notes.