For any sexually active woman trying to avoid pregnancy, there’s unfortunately always a chance of becoming unintentionally pregnant - which can be scary and overwhelming.
Since no form of birth control - including Natural Cycles - is 100% effective in preventing pregnancy, it’s important to understand your risk and how your chosen contraception method works. This way, you are aware of what risks you might be taking and can use this method in the best way possible.
Natural Cycles’ effectiveness
The best thing you can do to prevent pregnancy while using Natural Cycles is to avoid having unprotected sex on red days.
- Natural Cycles is 93% effective with typical use, which means that 7 women out of 100 get pregnant during 1 year of use.
- Using the app “perfectly,” i.e., if you do not have unprotected intercourse on red days, Natural Cycles is 98% effective, which means that 2 women out of 100 get pregnant during 1 year of use. The reason why there is still a small chance of pregnancy even if you use protection or abstain on red days is that:
- The condom or barrier method used on fertile days can fail.
- The algorithm can give a “false” green day within your fertile window. This method failure rate is monitored closely in our clinical studies, and the research shows it to be 0.7%, meaning that slightly more than half a woman out of 100 per year (or 7 out of 1000) becomes pregnant due to this reason.
In short, most pregnancies using Natural Cycles are due to unprotected sex on red days, which shows that it is very important to use protection during those days.
When you sign up for Natural Cycles, we walk you through how the app works; it’s typical and perfect use effectiveness. We also ask you to agree and acknowledge that you must either abstain or use protection on red days, such as condoms (or another form of barrier protection), to prevent pregnancies.
If you’d like to learn more about Natural Cycles and how its effectiveness compares to other forms of contraception, you can find more information here.
If you have any additional questions, please reach out to our customer support team here, and we’ve listed the following documents in full below: