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There’s an app for just about everything these days, so it’s not too surprising to learn that there’s an app for birth control: Natural Cycles.

What may be more surprising, however, is that Natural Cycles was the first app-based birth control cleared by the Food and Drug Administration (FDA).

According to Natural Cycles, being cleared means it’s a legitimate medical tool for birth control use.

So what exactly is Natural Cycles and how well does it work at preventing pregnancies? We have the details for you here.

Keep reading to learn more about Natural Cycles, how it works, its effectiveness, customer reviews, pricing, and more.

This app is considered an alternative form of birth control for those looking to avoid methods, like:

Using an algorithm based on daily basal body temperature and menstrual cycle information, Natural Cycles attempts to predict which days a person is fertile.

This type of tracking is called fertility awareness.

Fertility awareness is, of course, not a new birth planning (or avoiding) strategy.

Knowing which days you’re the most fertile can help you avoid or plan for pregnancies by either abstaining from or engaging in unprotected penis-in-vagina sex.

Usually, fertility windows are a few days before or during ovulation.

The Natural Cycles app makes the fertility awareness strategy easier to track since it’s digital and it takes into account a range of information.

Overall, it’s probably best to think of the app as a useful tool — if used consistently — for help with predicting fertile days, instead of a foolproof method for preventing pregnancy. There are, ultimately, no foolproof methods for preventing pregnancy, aside from abstaining from sex.

Natural Cycles works by analyzing your basal temperature readings, along with your menstrual cycle information, to tell you when you’re fertile or less likely to be fertile. That being said, the app will provide your fertility status in a definitive method: not fertile (green) or fertile (red).

According to research, basal temperature, the type of temperature taken after rest, is helpful in detecting ovulation.

Of course, there are some factors that can affect this measuring system. This is why frequent temperature readings taken at the same time every morning can help with accuracy.

On the company website, the brand says the Natural Cycles app is 93 percent effective with typical use, and that number increases to 98 percent with perfect use.

To get started, you must download (and purchase) the app, and select one of the plans:

  • NC Birth Control (preventing pregnancy)
  • NC Plan Pregnancy (finding fertile days)
  • NC Follow Pregnancy (monitoring pregnancy)

The app needs your menstrual cycle information before you’re ready to start taking basal thermometer readings, so you’ll enter that information first.

Once you have your basal thermometer, you can begin your temperature readings. Annual subscribers receive a basal thermometer from the company, whereas monthly subscribers can buy their own from a drugstore.

Temperature readings must be done immediately in the morning — while you’re still in bed, before even using the bathroom. Make sure you get at least three hours of uninterrupted sleep each night to ensure an accurate reading. You’ll enter your temperature into the app. On days when you may be feeling ill and suspect your temperature has spiked from sickness, you can skip entering your temperature.

The company website says you don’t have to take daily temperature readings, but making a habit of consistent readings most mornings helps the algorithm get to know your cycle better.

From here, Natural Cycles starts studying your data — your temperature readings and menstrual cycle information. This is how the app tells you which days are most likely to be fertile, with a definitive red (fertile) or green (not fertile).

Your screen will either show a green message saying “Not Fertile” or a red message that says “Use Protection” — meaning there’s a higher chance for pregnancy on that day.

The app can also track other things, like premenstrual syndrome(PMS), pain, mood changes, and libido.


  • FDA-cleared
  • research suggests it’s effective
  • no side effects
  • can be used to help prevent or plan for pregnancies
  • can track other information, like PMS, libido, and mood changes
  • can detect when a user is sick and will exclude this temperature so it does not impact data
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  • can be expensive
  • must be consistent with temperature readings and data entry for accuracy
  • can take a few cycles before it can most accurately predict your fertile or non-fertile days
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At this time, Natural Cycles has an average customer rating of 3.8 out of 5 stars on Trustpilot, a third-party review site.

Happy reviewers love that the app is a hormone-free method for preventing pregnancy, and overall feel they learn more about their body by using the app.

Less-than-stellar reviews point to unplanned pregnancies and some issues with being charged an auto-renewal fee without notice, or other subscription issues.

It’s also worth mentioning that Natural Cycles received some negative publicity in 2018 in the U.K. and Sweden. This happened when 37 users reported unwanted pregnancies after relying on the app for birth control.

At the time of publication, Natural Cycles offers two plans:

  • annual: $89.99
  • monthly: $9.99

If you’d like to get a sense of Natural Cycles before paying for the service, there’s a free demo mode you can test out by downloading the app.

It’s also eligible for Flexible Spending Account (FSA) and Health Savings Account (HSA) use.

There’s a slew of free and paid fertility apps on the market.

Currently, Natural Cycles is the only available birth control app the FDA has cleared for marketing in the United States and Europe. And unlike similar apps, it uses information based on your specific data. Although the Clue Birth Control app has been FDA cleared, it is not yet available for use in the United States.

For example, some apps predict fertility based on a 28-day cycle, but some people do not have this exact menstrual cycle.

Here are some app options similar to Natural Cycles:

  • Flo: Flo is a free app that also tracks your period, fertility, and ovulation information. It seems you can also log your basal body temperature using the app, but this feature isn’t advertised as heavily as it is for Natural Cycles.
  • Clue: Clue is a free (with in-app purchases) period and ovulation tracker. You can also log your basal body temperature with this app. Clue has also been FDA cleared.

If you’re looking for additional hormone-free birth control options, keep the following traditional contraception methods in mind:

If you have an iPhone, you can download Natural Cycles through the App Store. If you have an Android, you can download Natural Cycles through Google Play.

If you need accessories for related services offered by the app, you can purchase them on the brand’s website. You can purchase basal thermometers at most retailers.

Can Natural Cycles get ovulation wrong?

It’s important to point out that no form of birth control — app-based or otherwise — is 100 percent effective.

The FDA has cleared the Natural Cycles app, however.

A 2015 study looked at Natural Cycles’ effectiveness on 317 women aged 18 to 39 years.

Researchers reported that the number of false nonfertile predictions days were low — only 0.05 percent — suggesting that the app is a useful hormone-free birth control method.

How long does it take for Natural Cycles to work?

You can download the app and enter your menstrual cycle data right away, followed by your basal temperature readings shortly after.

The company says on its website that it can take 1 to 3 period cycles for the algorithm to understand your specific cycle information.

Does Natural Cycles really work?

Along with being FDA-cleared, the app has an overall positive brand reputation online, including its Trustpilot profile.

Some users have reported unplanned pregnancies after relying on the app. But the company warns that perfect use is the only way to get the most accurate information about your fertility. This means taking consistent readings at the same time every morning.

In general, no form of birth control prevents pregnancy 100 percent.

While no form of birth control is 100 percent reliable, emerging technology — like Natural Cycles and other fertility awareness apps — can be a useful, effective way to prevent pregnancy.

If you decide to use the Natural Cycles app to help you make health decisions, remember that technology can only predict your ovulation days. It cannot guarantee them.

If you want a more traditional form of birth control, consider talking with a healthcare professional about the range of options available.