No birth control method, including Natural Cycles, is 100% effective. This means that, unfortunately, unintended pregnancies can occur while using any form of contraception.
At Natural Cycles, we are proud to be the first and only FDA Cleared birth control app, and we do our best to help educate women on general birth control effectiveness while also making sure our users understand the factors that can contribute to an unintended pregnancy while using our product.
How effective is Natural Cycles?
Birth control effectiveness is calculated using the Pearl Index (PI). This represents the number of unintended pregnancies that occur when a group of 100 women use a particular method of birth control for a year.
Natural Cycles’ effectiveness, which is backed by rigorous clinical studies and real-world data, is shown in two key rates:
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Perfect Use Effectiveness: 98%
- This rate reflects how effective Natural Cycles is when used as intended. It only includes pregnancies due to a barrier method failing on a Red Day (i.e., condoms breaking) or the app giving a wrong Green Day.
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Typical Use Effectiveness: 93%
- This rate includes all unintended pregnancies, such as those due to having unprotected sex (this includes withdrawal) on a Red Day, as well as pregnancies that occur while the method is used as intended.
You can learn more about our effectiveness here: How effective is NC° Birth Control?
What causes unintended pregnancies when using Natural Cycles?
Unintended pregnancies, when using Natural Cycles, generally fall into these categories:
- Not using protection on Red Days
Natural Cycles provides "Red Days" when you are fertile and advises you to abstain from sex or use barrier protection (like condoms) if you wish to prevent pregnancy. Having unprotected intercourse on a Red Day is the most common reason for an unintended pregnancy with Natural Cycles. For this reason, all users must agree to abstain from unprotected sex on Red Days when signing up for the app.
It is also important to note that Natural Cycles does not recognize the withdrawal or pull-out method as a form of protection. You can learn more about its effectiveness here: How effective is the pull-out method?
- Malfunctioning of the barrier method
A barrier method needs to be used during intercourse on all Red Days to prevent pregnancy. If a condom or other barrier method breaks or malfunctions, this can lead to an unintended pregnancy, and this is included in our Perfect Use Effectiveness (98%).
- Method Failure
Wrongly attributed Green Days are rare but are monitored closely per our regulatory requirements and included in Natural Cycles' effectiveness rate. When the app distributes a wrong Green Day that leads to an unintended pregnancy, this is called the ‘method failure rate.’ Natural Cycles’ method failure rate is 0.5%, meaning that half a user out of 100 (or 5 out of 1000) becomes pregnant due to this reason per year. As a regulated medical device, Natural Cycles is subject to rigorous testing and yearly audits to ensure the effectiveness rate remains unchanged.
Our Support for You
We understand that every user's journey is unique, and experiencing an unintended pregnancy can be deeply personal. Natural Cycles is committed to supporting you through every stage of your reproductive health.
If you have experienced an unintended pregnancy, please know that our Customer Care team is here to listen with empathy and provide information, for instance, to help you understand your cycle data.