Starting Natural Cycles

There is no “one size fits all” when it comes to birth control, and choosing a method that is right for you is such a personal thing.

Is Natural Cycles suitable for me?

Natural Cycles may be a suitable option for you if you are looking for a natural method of birth control, are willing to use protection or abstain from sex on red days and have a lifestyle that enables you to take your temperature first thing most mornings. Using Natural Cycles does require a level of commitment, so the better it suits your lifestyle, the more you will get out of it.

No method of birth control is 100% effective. It is important to consider all the factors involved before making an informed decision. Natural Cycles is supported by clinical evidence and has been shown to be 93% effective with typical use. This includes both a technicality with the algorithm (method failure),  as well as human error, i.e. a woman having unprotected sex on a red day.

Looking at other commonly used birth control, the IUD is considered to be 99% effective, whereas the male condom is 82% effective with typical use.1 

You can discover more about birth control effectiveness in our user manual.

Natural Cycles may not be right for you if you have a medical condition where pregnancy would be associated with a significant risk to you or the fetus.

Find out if Natural Cycles could be a suitable option of birth control for you.

1.“Family planning/Contraception” World Health Organization, 2018.

What About Irregular Cycles?

Small irregularities are quite common, especially if you have recently stopped using hormonal birth control. The Natural Cycles algorithm takes factors such as cycle regularity and temperature fluctuations into account when analyzing your unique cycle and calculating your status for the day.

Some women have irregular menstrual cycles (i.e. cycles with a length of less than 21 days or greater than 35 days). Identifying your fertility is more difficult in these circumstances, and the application will display an increased number of red days, which may reduce your satisfaction with Natural Cycles as a birth control method.


Maya, Entrepreneur & Yoga teacher

- For me, it’s perfectly reasonable to make an effort and adapt to changes so that I can feel good.

So when can I get started?

If you are not using hormonal birth control, you can get started right away.

Natural Cycles does not work alongside hormonal birth control since hormonal methods inhibit ovulation. But you can use the app in demo mode and can easily switch to the normal mode when you are ready. It can take several cycles after discontinuing hormonal birth control before becoming more regular again. You should expect more red days during these cycles and therefore expect to use protection or abstain more frequently.

There’s more information in our User Manual about switching birth control and getting started with Natural Cycles after stopping hormonal birth control.

If you have recently given birth and are breastfeeding , you may not ovulate for the first 4-6 months. Natural Cycles will detect your first ovulation 2 weeks before your first menstruation but until then you will only see red days in the app. Even though you are not ovulating, it is still important to use birth control or abstain from intercourse on red days.

To get started you will need a basal thermometer, which is more sensitive than a regular fever thermometer as it shows two decimals. The good news is that you will get one sent right to your doorstep when you get our annual subscription.

What to expect in the first few months

Measuring your temperature is probably new to you, so getting into the habit might take you a week or two. You can activate reminders in the app to keep you on track and a good tip is to put the thermometer beside your bed and on top of your phone – that way you can’t miss it when you wake up.

When not to measure

Remember to read the User Manual carefully to make sure you understand any factors that could affect your basal body temperature – such as sickness, taking painkillers, long-distance traveling or feeling hungover. On these days, you should tap ‘Deviating temperature’ when adding your reading into the app.

Green days increase with time

Since every woman and every cycle is different, the Natural Cycles algorithm will take a little while to get to know you and your individual cycle. That’s why you get more red days in the beginning; the number of green days increases as the algorithm gets to know your individual cycle pattern. 

Depending on the regularity of your cycle and how frequently you update your temperature data (this should be at least 5 times a week), you can expect to see an increase in green days as the algorithm learns your unique cycle. This can take around 3 months, so it’s best to be patient – the more consistently you use Natural Cycles, the more you’ll get back

Get to know your body

Getting to know your body is fun, liberating and empowering. We’ve set up a list of achievements in the app that will guide you along the way. Soon you will see your very own temperature curve, the statistics that sit behind your cycle and much more.