- Repeated longitudinal sampling: Thousands of participants from two established UK cohort studies will provide menstrual fluid samples across three menstrual cycles using specially designed period pads.
- Samples linked with extensive data: The biospecimens will be combined with daily symptom tracking, questionnaires, and existing long-term health and genetic information.
- Emerging biobanking model: CycleTrack demonstrates how self-collected menstrual fluid can be developed into a structured research resource while highlighting the importance of standardized collection, pre-analytics and specimen-to-data linkage.
Researchers from the Universities of Exeter and Bristol have launched CycleTrack, a large-scale study that will create a menstrual fluid biobank linked with longitudinal health, genetic and real-time symptom data.
According to the University of Exeter announcement, thousands of participants will provide menstrual fluid samples over three menstrual cycles using specially designed period pads. Participants will also record symptoms through a daily tracking app and complete detailed questionnaires.
Exeter describes the project as creating the world’s largest menstrual fluid biobank specifically for people in their mid-30s. Rather than relying on a single collection point, CycleTrack will repeatedly sample individuals across multiple cycles and link those specimens with information already accumulated through two long-running UK cohorts.
Linking Menstrual Fluid With Longitudinal Cohort Data
A key feature of CycleTrack is its integration with Children of the 90s (ALSPAC) and Born in Bradford.
Children of the 90s recruited pregnant women in the Bristol area in 1991–1992 and has subsequently followed participating families for decades. Born in Bradford is another major longitudinal cohort examining factors that influence health and wellbeing across the life course. Previous collaborative research involving the two cohorts has drawn on genetic, environmental, lifestyle and reproductive data.
CycleTrack adds a new layer to those resources: repeated menstrual fluid biospecimens accompanied by prospective menstrual and symptom information.
Researchers hope that combining these samples with long-term health and genetic data will reveal biological signals associated with differences in menstruation and related conditions. Potential applications include earlier identification of heavy menstrual bleeding and associated risks such as iron deficiency, although these remain research objectives rather than established clinical outcomes.
For biobanks, the project illustrates the additional research value that can be created when a new biospecimen type is incorporated into an established longitudinal cohort. The utility of the collection derives not only from the biological material itself, but from its connection with historical, genetic, phenotypic and prospectively collected data.
Menstrual Fluid Emerging as a Research Biospecimen
Menstrual fluid — frequently described in research as menstrual effluent — is gaining attention as an accessible biospecimen containing cells, tissue fragments and molecular components associated with the endometrium.
A 2026 systematic review of menstrual effluent research identified 35 studies examining its use in endometriosis research. The review concluded that menstrual effluent can capture biologically relevant features of endometrial and disease processes, while also finding substantial methodological heterogeneity and a lack of prospective clinical validation.
Importantly, that literature concerns endometriosis and should not be interpreted as evidence about CycleTrack itself. It does, however, demonstrate why larger and more systematically characterized menstrual-fluid collections may be valuable to biospecimen-enabled research.
Biobanking.com previously reported on the Australian Menstrual Fluid Biobank for Endometriosis Research (AMBER), which was established to support research into endometriosis diagnostics and more personalized treatment approaches. CycleTrack extends the concept into a broader longitudinal population setting rather than focusing exclusively on a single disease.
Together, these initiatives suggest that menstrual fluid is beginning to develop from a relatively uncommon research material into a more systematically collected biospecimen for women’s health research.
At-Home Collection Highlights Pre-Analytical Considerations
CycleTrack is also relevant to biobanking because much of the specimen collection takes place outside a conventional clinic or laboratory.
The 2026 systematic review found wide variation in how menstrual effluent has been collected across previous studies, including menstrual cups, pads, aspiration and other approaches. It also highlighted inconsistent reporting of variables such as cycle timing, collection-device dwell time, transport temperature, time to processing and the use of preservatives or anticoagulants.
Such factors can affect specimen characteristics before laboratory analysis and therefore influence reproducibility and fitness for downstream research.
For a longitudinal resource using participant-led collection, consistent procedures for sample identification, collection timing, transport, processing, preservation and linkage to participant-generated data are consequently important considerations. These issues align with principles addressed in ISO 20387 and the ISBER Best Practices for Repositories, including specimen-specific procedures, documentation of relevant pre-analytical information, specimen integrity and traceability.
Supporting Research Into Heavy Menstrual Bleeding
CycleTrack forms part of The Missed Vital Sign, a $50 million women’s health research program led by Wellcome Leap. University of Exeter researcher Professor Gemma Sharp is among the program’s selected research performers.
The program aims to reduce the time women experience heavy menstrual bleeding before receiving effective treatment from around five years to five months. Its research priorities include identifying people at risk of iron deficiency, improving understanding of the biological causes of heavy menstrual bleeding, developing new diagnostic approaches and improving treatment stratification.
From a biobanking perspective, CycleTrack is therefore notable for more than its proposed scale. It combines repeated self-collected biospecimens, prospective digital symptom data and decades of longitudinal cohort information within a single research framework.
If those components can be consistently collected and linked at scale, the project could provide a useful model for other biobanks studying biological processes that change over time and are difficult to capture through conventional clinic-based sampling.
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