Take Control Of Your Fertility

16K ratings in the App Store
You must be over the age of 18
Does not protect against STIs
FDA Cleared
CE 0123

Know Your Fertility in 3 Quick Steps

1. Measure

When you wake up in the morning, use the Natural Cycles thermometer to take your temperature.

2. Add data

Enter your temperature into the app and let Natural Cycles analyze your unique cycle and identify your fertility status.

3. Check your status

Discover if today is a red day (use protection) or a green day (you’re not fertile - no need to use protection).


When you use Natural Cycles perfectly, the birth control app is 98% effective. Perfect use means using condoms or abstaining from sex on red days (when you’re fertile).

Read more about effectiveness


Get to know your body with a hormone-free birth control app, so you can prevent pregnancy on your own terms.

Read more about how it works

FDA Cleared.

Natural Cycles is the first and remains the only app to be cleared by the US FDA for the use of birth control. The app is also the only app to be CE marked in Europe.

Read more about regulatory clearance

Subscription to hormone-free birth control gives you:

  • A personalized daily status that tells you whether it’s a green or a red day
  • Personal statistics and increased knowledge of your unique cycle
  • Bespoke notifications and messages about PMS, breast exams and more
  • Unique understanding of where you are in your cycle, putting you in control of your body
No method of contraception is 100% effective. Natural Cycles does not guarantee that you cannot get pregnant, it only informs you whether and when you can become pregnant based on the information that you enter into the application.