Users must explicitly choose to share overnight wrist temperature data measured by Apple Watch from the Apple Health app with the Natural Cycles app and can manage permissions at any time. Users can also choose which data from the Natural Cycles app, if any, they’d like to share to the Health app. Once in the Health app, a user's data is securely stored and the user is in control of who can access their data.
Protecting users' information has always been a top priority for Natural Cycles and on top of NC° Secure (Natural Cycles’ privacy protection program) a large part of our recent FDA 510(k) clearance around this integration was specific to cybersecurity. You can read more about how Natural Cycles protects your data here.