Natural Cycles is the first and only app of its kind cleared by the FDA as birth control. Most other fertility apps assume your cycle is 28 days long. This means the fertile window they predict is not personalized to your cycle. So, how can it be true to you? Our algorithm significantly reduces the risk of you receiving an incorrect fertility status since it uses your unique temperature data, which reduces the risk of unwanted pregnancy and can even help you plan for pregnancy with greater precision. 

Plus, not all period trackers keep secrets — some might even share them. With the Natural Cycles app, your data stays yours. We provide an advanced data privacy protection program designed to keep your data safe. Find out why women around the world choose Natural Cycles.

To get started:
1. Sign up for Natural Cycles (purchase a subscription and measuring device)
2. Download the app
3. Follow the steps to set up your device
4. Start measuring!

Birth control costs money to make and supply. A subscription to the Natural Cycles app helps make hormone-free birth control more accessible, giving you more choices to find what works for you — all while supporting women’s health research.

Because we charge a subscription, we don’t need to profit from selling users’ data like some “free” apps do. Natural Cycles is committed to data privacy, and as a regulated medical device, we are required to comply with the FDA’s cybersecurity requirements.

We offer two plans: annual or monthly. Click here to find the right subscription option for you.

Yes. The effectiveness of Natural Cycles is supported by clinical evidence, which shows a typical use effectiveness rate of 93% and a perfect use effectiveness of 98%. Read more on the science behind our effectiveness.