Menstrual Blood May Be One of Medicine’s Most Overlooked Research Tools
Author: Hala Salah, BSc Student, University of Calgary | Editors: Romina Garcia de leon, Tashi Stampp (blog coordinators) Reviewer: Mateja Perovic
Published: August 7th, 2026
Rethinking an Everyday Biological Sample
When most people think about medical testing, they picture needles, vials, and laboratory blood draws. Blood testing has become one of the most common tools in healthcare. It can help detect health problems early and diagnose disease and infection. Despite how routine blood testing has become, it is not always easy or accessible for everyone. Because of its invasive nature, many people experience pain or anxiety around needles, increasing reluctance to participate voluntarily in research. Traditional blood testing also requires specialized equipment and providers, increasing health costs significantly.
Every month, 1.8 billion people naturally produce another biological sample. Researchers are now starting to realize that it may hold equally valuable medical information.
What Makes Menstrual Blood Different?
Menstrual blood as a biospecimen has been long ignored in medicine and research settings. For decades, it has been treated as waste and an “inconvenience” rather than as a potential source of scientific insight. This growing field provides a unique look into reproductive health, immunity, and physiological processes occurring throughout the body. It is part of a larger shift in women’s health research: recognizing that menstruation isn’t just a monthly inconvenience, but a complex biological process that may tell us more about our health than previously understood.
One reason menstrual blood has been misunderstood is because of its misleading name. Menstrual fluid is not just blood leaving a woman’s body every month. It is a biologically complex mixture of blood, cells from the uterine lining, proteins, immune cells, hormones, and other biological material released during the menstrual cycle. Proteomic analyses have identified hundreds of proteins in menstrual blood, including approximately 400 proteins not typically found in systemic blood.
One example of a unique menstrual blood biomarker is urocortin 3. This protein is involved in inflammation, blood vessel activity and programmed cell death. Because inflammation plays a major role in many gynecological diseases, tracking proteins like urocortin 3 in menstrual blood may provide researchers with a more direct window into what is happening within the uterus than a traditional blood sample.
This wealth of proteins makes menstrual blood a valuable diagnostic tool. It can show signs of inflammation and possible health issues. It also provides insights into menstrual cycle regularity and overall health status.
A New Window into Women’s Health
Researchers are especially interested in menstrual blood because many gynecological conditions are strongly linked to abnormalities in immune and inflammatory pathways. Since menstrual fluid comes directly from the uterine environment, it can contain many biomarkers that may provide clues about diseases that are often difficult to diagnose and monitor.
For instance, emerging research on menstrual blood is particularly meaningful for endometriosis – a condition where the growth of the uterine tissue occurs outside the uterus leading to infertility and severe pain. Despite affecting over 190 million people worldwide, diagnosis often takes years because symptoms are normalized and diagnosis usually requires invasive procedures. Researchers are now exploring whether menstrual blood could help improve non-invasive diagnosis because the disease is strongly associated with inflammation and immune dysfunction. Because menstrual fluid contains endometrial tissue and inflammatory proteins, scientists have identified biomarkers that appear elevated in people with endometriosis.
Specifically, CXCL5 and IL1RN are examples of inflammatory proteins that have been found at significantly higher levels in menstrual blood from people with endometriosis than in healthy individuals.
Though still in the experimental stage, these results suggest that menstrual blood could lead to earlier, easier diagnosis of endometriosis. This could mean faster recognition, fewer delays, and less invasive care for those living with chronic pain.
Innovations in Menstrual Blood Collection
Several methods for collecting menstrual blood non-invasively for diagnosis and research purposes are being explored. This has included menstrual cups, tampons, sanitary pads, absorbent sponges, and newer wearable technologies. However, some collection methods can still feel uncomfortable or inconvenient for users.
To address these barriers, researchers are developing less invasive and more accessible collection technologies. One example, MenstruAI, is a wearable diagnostic platform directly integrated into a sanitary pad that can detect biomarkers in menstrual blood without requiring separate sample collection or laboratory processing. Results can be linked to a smartphone, helping identify signs of inflammation, infection, cancer, and endometriosis. Technology like MenstruAI could make menstrual health monitoring more convenient, affordable, and accessible while helping transform a biological sample often treated as waste into a valuable source of health information. These non-invasive technologies can also be used from home. This may be especially valuable in underserved or low-resource settings where access to healthcare professionals and laboratory infrastructure is limited.
Despite its potential, menstrual blood research is still in its early stages. However, researchers still need to better understand how reliable these tests are, how samples should be collected and stored, and how these tools can be used safely and affordably in real healthcare settings. Menstrual blood is unlikely to replace conventional blood testing entirely, and many of these technologies will require further validation before widespread clinical use.
Redefining Menstrual Blood in Medicine
However, the growing interest in menstrual fluid diagnostics reflects something much larger than a new testing method alone. Ultimately, menstrual blood research is not simply about finding alternative ways to collect biological samples, but rather represents a shift toward more inclusive, accessible, and patient-centered healthcare. By studying menstrual fluid more seriously, researchers may uncover new opportunities for earlier diagnosis, personalized medicine, and improved understanding of diseases that have historically been overlooked. What was once dismissed as waste may ultimately become one of medicine’s valuable and accessible sources of health information.
