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# Mobile App Cleared as Contraceptive Method
- URL: https://www.fdaweb.com/mobile-app-cleared-as-contraceptive-method/
- Published: 2018-08-13T12:00:00.000Z
- Updated: 2026-09-15T00:25:20.000Z
- Author: David McFarland
- Tags: Devices, #legacy-id-D5142091

FDA has granted de novo marketing for Natural Cycles Nordic’s Natural Cycles mobile medical application that can be used as a method of contraception to prevent pregnancy. The app contains an algorithm that calculates the days of the month a woman is likely to be fertile based on daily body temperature readings and menstrual cycle information, a contraceptive method called fertility awareness. Designed for mobile devices, it is intended for use in pre-menopausal women aged 18 and older.

  
Marketing authorization was based on data from clinical studies involving 15,570 women who used the app for an average of eight months. “The app had a ‘perfect use’ failure rate of 1.8%, which means 1.8 in 100 women who use the app for one year will become 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,” an [FDA release](https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm616511.htm?ref=fdaweb.com) says. “The app had a ‘typical use” failure rate of 6.5%, which accounted for women sometimes not using the app correctly by, for example, having unprotected intercourse on fertile days,” it says.