GoKawiilBMJ analysis warns cycle-tracking apps pose privacy and accuracy risks
A new peer-reviewed analysis in The BMJ examines digital cycle-tracking apps used by an estimated 50 million people worldwide to monitor menstruation, fertility and 'cycle syncing' habits. The authors, including Tulane's Katharine Lee, say these apps' predictions rely on self-reported bleeding dates rather than actual hormone measurements, making them unreliable for forecasting ovulation or fertile windows, and that they cannot diagnose menstrual disorders or the causes of painful periods.