Protective methods for red days

Protective Methods for Red Days

For Natural Cycles to be effective as a birth control method, you need to use protection on red days or abstain from penetrative vaginal sex to prevent pregnancy. Red days are the days in your cycle when you’re most fertile (or the algorithm doesn’t have enough data yet to give you green days). 

How you choose to protect yourself on red days is a personal choice. Since no method of birth control is 100% effective, if you are sexually active, there will always be a risk of pregnancy, but some birth control options are more effective than others. Natural Cycles recommends using male condoms or abstaining from vaginal intercourse on red days. 

Understanding the effectiveness

Birth control effectiveness is usually referred to in terms of perfect use and typical use, and this reflects 100 women using a method over the course of a year. Perfect use reflects a method being used according to its instructions (so any pregnancies that occur are due to the method failing, e.g., a condom breaking). Typical use accounts for user error (e.g., a condom is worn incorrectly), and the method fails.

Natural Cycles has typical use effectiveness of 93% and is 98% effective with perfect use. Looking at typical use, this means that 7 out of 100 women will get pregnant using Natural Cycles during a year - this includes the app giving an incorrect green day and users having unprotected sex on red days.

Below is a table showing a selection of non-hormonal birth control methods. It shows the number of pregnancies during one year when 100 women use these methods (with both typical and perfect use). This number is known as the Pearl Index. 

Number of pregnancies per 100 women in one year:

* This should be logged as unprotected intercourse in the app. Note that we do not recommend using withdrawal.
** Must be combined with spermicides.