Does Natural Cycles require a thermometer

Yes. Natural Cycles requires daily basal body temperature measurement, typically immediately upon waking before getting up. The app includes a basal thermometer with annual subscriptions. The temperature data is the core input for fertility prediction; without it, the algorithm cannot function as designed.

Can Clue be used as birth control

Clue is not FDA-cleared for contraceptive use and explicitly does not market itself as a birth control method. Clue can help track fertile windows, but the predictions are not clinically validated for contraception. Only Natural Cycles holds FDA clearance for that specific use case among period tracker apps.

Can Natural Cycles data be used in a court case

Yes. Natural Cycles stores user data on its servers. A valid court order can compel the company to produce that data. FDA De Novo clearance provides regulatory accountability for the contraceptive method's efficacy, not immunity from legal data requests. Users in jurisdictions with reproductive health legal exposure should understand that server-based storage creates this risk regardless of the company's commercial practices.

Does Clue encrypt my period data

Clue encrypts data in transit and at rest. Encryption protects data from external breaches but does not prevent Clue from accessing it, and does not prevent court-ordered disclosure. Encryption is a security measure against unauthorized access, not a substitute for on-device storage when the concern is legal compulsion.

comparisons

Natural Cycles vs Clue: Data Privacy Compared

Both are cloud-based period trackers with no documented data-selling scandals. Here is what separates them on privacy architecture and data risk.

Two Apps, Two Different Jobs Natural Cycles and Clue occupy different positions in the period tracker category. Natural Cycles is built specifically for fertility awareness as a contraceptive method. The FDA clearance it holds is for that purpose: as a contraceptive decision support tool. Clue is a comprehensive cycle and health tracker. It covers periods, fertile windows, birth control reminders, mood, symptoms, and research backed health analysis. It does not claim contraceptive clearance. Accuracy and the Temperature Requirement Natural Cycles' contraceptive effectiveness depends on daily basal body temperature tracking. BBT rises slightly after ovulation, providing a retrospective signal for fertility prediction. The algorithm combines this with cycle history. Typical use effectiveness is 93%, functional as a method, but lower than hormonal contraception. Clue predicts cycles and fertile windows without requiring temperature input. It uses historical cycle data, symptoms, and logged health information. For general cycle awareness, this is sufficient. For contraceptive decisions, the lack of FDA clearance means it is not in the same category as Natural Cycles. Two Apps Without F