A Novel Approach to Characterization of the Female Hormone Profile: Feasibility and Research Application of Daily At-Home Urine Hormone Monitoring

Introduction: Accounting for and characterizing hormonal status and menstrual phase can add complication, time, and expense to studies, creating a barrier to conducting rigorous female-specific research. Recent advances in at-home urine hormone testing present a potentially feasible method for quantifying daily estrogen (E), progesterone (PDG), and luteinizing hormone (LH) across the menstrual cycle, that could enhance research feasibility and precision. Purpose: to evaluate the feasibility and research utility of at-home daily urine hormone monitoring for characterizing female hormone profiles. A secondary aim was to assess the relationship between daily urine and salivary hormone concentrations and patterns. Methods: Thirty-three healthy women, (Age: 23.8±0.7yrs; BMI: 23.4±0.5kg/m 2 ; %BF: 27.3±1.0%), including eumenorrheic (EUM, n=13), hormonal intrauterine device users (IUD, n=10), and oral contraceptive users (OC, n=10), completed daily urine and saliva sampling over ~1–2 hormone cycles. An at-home smartphone-compatible monitor was used to quantify urine E, PDG, and LH from lateral flow assays. Saliva E and PDG was assessed using enzyme immunoassays. Associations between daily urine and saliva hormone concentrations were evaluated using within-individual Pearson correlations; hormonal patterns were assessed using correlations of smoothed time-series data. Results: Compliance with daily hormone testing was high (92.8±8.7%) across 36.0±13.7days of tracking. Key menstrual cycle features were identified within 1–2 cycles. Associations between daily urine and saliva E and PDG concentrations were weak to moderate (r=0.36-0.81; p<0.001-0.046) in 25% and 34% of cycles, respectively. Comparatively, associations between E and PDG patterns were moderate to strong (r=0.49-0.99; p<0.001-0.050) in 41% and 66% of cycles, respectively. Conclusions: At-home daily urine hormone monitoring is a feasible method for characterizing menstrual cycle hormones that could advance the quality, inclusivity, and interpretability of female health and physiology research.