Epigenetic age profiling of menstrual blood collected using long-term stored Q-Pads

Menstrual blood provides direct access to endometrial-derived material, but self-collected biospecimens suitable for cohort-scale DNA methylation studies remain limited. We assessed whether dried menstrual blood collected using Q-Pads and stored at room temperature for more than two years supports genome-wide DNA methylation profiling and epigenetic biomarker estimation. Ten of sixteen samples passed array-level quality control, and nine were retained as analytically robust female samples. Multiple epigenetic clocks correlated with chronological age, with the Horvath clock showing the strongest performance. These findings support dried menstrual blood as a promising minimally invasive biospecimen for reproductive aging and endometrial health studies.