Objective: To investigate symptomatology throughout the menstrual cycle, including the frequency of symptoms reported for each phase of the cycle and the relationship between symptoms and individual characteristics. Methods: This study included self-reported cycle information and symptoms during ovulatory 10 menstrual cycles in users of the mobile application Flo. Symptom frequency was described overall, by phase, and by day. Relationships between symptoms and individual characteristics (age, body mass index) were tested with logistic regression. Results: 224,676 unique users and 498,126 unique cycles were included in the analysis. Somatic symptoms were most frequently reported, logged in 85.3% of cycles. Of total symptoms logged, somatic, gastrointestinal, and negative mood symptoms were most prevalent in the late luteal and bleeding days, while positive mood and discharge were most common in the fertile window. Symptom experience differed by age. Conclusions: Menstrual cycle-related symptoms are very common and vary throughout the cycle phases. While most women report negative symptoms including pain, bloating, and negative mood, women also report positive symptoms such as energetic and happy mood. Self-reported data from cycle tracking and health apps can improve our understanding of the prevalence and variability of menstrual-related symptoms.

Kimberly Peven: Flo Health UK Limited (Employment), Ryan Bamford: Flo Health UK Limited (Employment), Liudmila Zhaunova: Flo Health UK Limited (Employment, ownership interest includes stock, stock options), Rodion Salimgaraev: Flo Health UK Limited (Employment, ownership interest includes stock, stock options), Carley Prentice: Flo Health UK Limited (Employment), Aidan Wickham: Flo Health UK Limited (Employment), Jazz Croft: Flo Health UK Limited (Employment), Sonia Ponzo: Flo Health UK Limited (Employment, ownership interest includes stock, stock options). Other authors did not report any potential conflicts of interest.

This study was funded by Flo Health UK Limited

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IRB of Mayo Clinic waived ethical approval for this work

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