To evaluate menstrual fluid as a non-invasive specimen for detecting systemic and reproductive protein biomarkers, including those reflective of neuroinflammatory and hormonal states.

Menstrual effluent offers a unique window onto reproductive and systemic health, including inflammatory physiology, but it is underutilized in clinical practice. Its composition of blood, uterine, and vaginal tissues enables simultaneous assessment of reproductive, physiological, and immune function for detecting inflammatory diseases like endometriosis or multiple sclerosis (MS). We developed a standardized tampon-based collection kit that preserves nucleic acids and proteins for downstream clinical assays.

Menstrual effluent was collected using a tampon-based kit containing preservation buffer and centrifuged to separate cellular and fluid fractions. Supernatants were analyzed using an automated immunoassay platform for anti-Müllerian hormone (AMH), estradiol, progesterone, interleukin-6 (IL-6), cancer antigen 125 (CA125), and others. Transferrin was used to normalize for blood content variability.

Biomarkers were quantifiable across samples. AMH declined with participant age, and progesterone increased in users of progestin-only therapy. IL-6 and CA125 rose with transferrin-rich, darker samples, confirming transferrin as a useful normalization factor. Transferrin levels were highest on cycle days 1–2 and decreased through days 3–5, consistent with changes in blood content over menstruation.

Tampon-based menstrual sampling enables reproducible quantification of hormonal, inflammatory, and neurological biomarkers. Transferrin normalization improves comparability across samples and supports menstrual effluent as a scalable biospecimen for endocrine and neuroimmune monitoring. These finding highlight the potential of menstrual fluid as a valuable, non-invasive matrix for clinical and research applications in reproductive and inflammatory health.