An Overview of Natural Birth Control

Measure your temperature first thing in the morning, enter it into the app and know when you need to use protection or abstain from sex to prevent a pregnancy.

What is Natural Cycles?

Natural Cycles is an effective*, natural method of birth control. And so much more. It’s the app that gives you the knowledge to feel in tune with your body and truly understand how your cycle works.

*Natural Cycles is 93% effective under typical use. This means that an average of 7 out of 100 women will get pregnant in a year when using Natural Cycles.

What is Natural Cycles
How it works

How does it work?

Natural Cycles works by identifying the fertile and non-fertile days in your cycle. Did you know that you are only fertile on up to six days in one cycle? The day of ovulation (when your ovaries release an egg to be fertilized) and the five days leading up to ovulation; this accounts for the possible length of time that sperm can survive inside your body (a maximum of five days).

To use Natural Cycles, you take your temperature first thing in the morning and enter the information into the app. It’s important to measure basal body temperature – the lowest body temperature when at rest – using a basal thermometer which shows two decimal points.

The Natural Cycles algorithm uses this information to detect ovulation, thereby identifying green days, when no protection is needed, or red days, when you and your partner should use condoms or abstain from sex to prevent a pregnancy.


Can I have sex without protection?

Yes, on a green day. These are the days that the algorithm determines that you are not fertile and so no protection is needed.

Just keep in mind that Natural Cycles does not protect against Sexually Transmitted Infections (STIs) in any way.

Not fertile screen
Use protection screen

When do I need to use protection?

For Natural Cycles to be effective as a method of birth control, you must either abstain from having sex or use protection on red days, such as condoms or another form of barrier methods, to prevent pregnancies. The number of green days increases as the algorithm gets to know your individual cycle pattern.

A regular cycle, a steady temperature and consistent data entry will all contribute towards frequent green days. Be patient and give the algorithm a few months to learn your unique cycle.

Is Natural Cycles effective?

In an analysis of more than 15,000 women with a total exposure time of 7,353 women years, Natural Cycles demonstrated a typical use Pearl Index of 6.5. This means that in total 6.5 women out of 100 women get pregnant during one year of use with Natural Cycles.


It is important to note that even if you use the app perfectly, you can still have an unintended pregnancy. Before you get started, read the User Manual thoroughly as this contains all the information you will need to use Natural Cycles effectively.

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