A natural birth control app used as a form of contraception was approved for the first time by the U.S. Food and Drug Administration last week, according to People magazine.
The app Natural Cycles, made in Sweden, uses body temperature to determine if a woman is most fertile, giving her an opportunity to use protection or abstain from sex to avoid pregnancy, the magazine said.
A woman takes her temperature orally using a basal body thermometer after waking up and then enters the information into the app, People magazine said. The Natural Cycle app through the month will give the woman a "green light" if her temperature reading indicates a less fertile day and a "red light" on her most fertile days.
Natural Cycles said women have about 10 "red light" days a month, according to People.
"Consumers are increasingly using digital health technologies to inform their everyday health decisions, and this new app can provide an effective method of contraception if it's used carefully and correctly," Dr. Terri Cornelison, assistant director for the health of women in the FDA's Center for Devices and Radiological Health, said in a statement.
"But women should know that no form of contraception works perfectly, so an unplanned pregnancy could still result from correct usage of this device," Cornelison added.
According to the FDA study, clinical studies that evaluated the effectiveness of Natural Cycles with 15,570 women who used the app for an average of eight months found a "perfect use" failure rate of 1.8 percent.
That means that 1.8 in 100 women who used the app for one year became pregnant because they had sexual intercourse on a day when the app predicted they would not be fertile or because their contraceptive method failed when they had intercourse on a fertile day, the FDA said.
The app had a "typical use" failure rate of 6.5 percent, which accounted for women sometimes not using the app correctly by, for example, having unprotected intercourse on fertile days, the administration said.
Birth control pills have a 9 percent failure rate and male condoms have an 18 percent failure rate, according to the Centers for Disease Control and Prevention.
The Guardian reported, though, that Natural Cycles came under investigation by Swedish authorities earlier this year after a hospital confirmed 37 cases of unwanted pregnancies among women who used the app for contraception.
The Swedish broadcaster SVT reported that the 37 cases were identified out of the 668 women who sought an abortion at one of Stockholm's largest hospitals from September to December 2017, according to The Guardian. That led the hospital to report the app to Sweden's Medical Products Agency.
© 2026 Newsmax. All rights reserved.