The Gender Medical Research Gap: Menstrual Blood Diagnostics

Two billion people produce it every month. It contains blood, endometrial tissue, immune cells, and local inflammatory markers: a live readout of the reproductive tract that you cannot get any other way short of a biopsy.

And until about eighteen months ago, there was no FDA-cleared test that used it.

Not because it doesn’t work. Because nobody funded the question.

In February 2026, The BMJ published a study out of Hubei province, China. Three thousand and sixty-eight women, aged twenty to fifty-four, all with regular cycles, recruited across seven sites (four urban, three rural) between September 2021 and January 2025.

The method was almost aggressively simple. A sterile cotton strip, attached to the absorbent part of an ordinary sanitary pad. Wear it during your period. Send it in.

Every participant also went through standard cervical screening with a clinician collecting cells from the cervix and both methods were measured against biopsy results.

The pad matched the speculum.

For detecting CIN2+, the precancerous cervical changes that HPV causes, the minipad returned 94.7% sensitivity. The clinician-collected sample returned 92.1%. Specificity was marginally lower for the pad, 89.1% against 90.0%. And the negative predictive value: the probability that a negative result is genuinely negative was identical for both. 99.9%.

The researchers concluded that non-invasive menstrual blood sampling improves acceptability and feasibility for large-scale screening, and that these findings support integrating menstrual-blood-based HPV testing into national cervical cancer screening guidelines.

One gynecologic oncologist not involved in the study called it potentially practice-shifting, with real implications for screening equity.

Cervical cancer is one of the leading causes of cancer death in women worldwide. It is also one of the most preventable cancers we know of because screening catches it, treatment works, vaccination prevents it.

Two thirds of women globally have never been screened.

Not once.

Sit with the shape of that. We have a cancer we know how to prevent, and most of the people who could get it have never been tested. In the UK, roughly 62% of eligible people say they worry about discomfort at screening. One in three skip the appointment entirely.

The system’s read on this has always been that women are non-compliant. Bad at self-care. In need of a reminder letter, a public health campaign, a nudge.

The actual problem was that the test required a stranger, a speculum, a clinic, a day off work, and a tolerance for being uncomfortable in a paper gown and nobody with the funding ever asked whether there was another way in.

There was. It leaves the body monthly. We were taught to wrap it in three layers and hide it at the bottom of the bin.

Once you stop treating menstrual effluent as waste, the diagnostic ceiling lifts fast.

Researchers have shown menstrual blood can be used to estimate serum levels of at least eight biomarkers, including HbA1c, cholesterol, creatinine, hsCRP, LDL, HDL, triglycerides and FSH. That’s metabolic health, cardiovascular risk, inflammation and hormonal status, from a pad.

In 2025, Hospital Clínic de Barcelona, working with the Insular University Hospital of Gran Canaria, analyzed DNA methylation profiles in menstrual blood as a diagnostic route for endometriosis. Another 2025 platform used digital droplet ELISA to detect inflammatory cytokines in menstrual blood at a diagnostic quality comparable to surgical assessment.

Read that again. Endometriosis, currently diagnosed by cutting a hole in a woman’s abdomen after she has spent five to ten years being told her pain is normal: potentially detectable from the thing she is already bleeding into a pad.

A multicentre validation trial for exactly this is running now, with the study registration noting the diagnostic delay in plain institutional language: at least one in ten women, five to ten years to diagnosis, definitive confirmation currently requiring invasive laparoscopy.

And a 2026 review flagged the other half of the story: menstrual blood–derived stem cells, or MenSCs, alongside immune cells, cytokines and growth factors, with real promise for regenerative therapy in endometrial disorders. Not just reading the body. Repairing it.

Dr. Sara Naseri started asking in 2014, as a medical student. She has said she was shocked to find almost no data on how a fluid two billion women have access to monthly could be used to improve healthcare. Her company, Qvin, secured FDA clearance for the Q-Pad and A1c Test in January 2024: the first ever FDA-cleared menstrual blood health test, approved for at-home collection and over-the-counter sale. Work with Stanford School of Medicine has since validated markers for anemia, fertility, perimenopause, endometriosis and thyroid health. That took a decade.

Ridhi Tariyal went to her doctor at Brigham and Women’s to ask how much longer she had to have children, and was told no such test existed. She has an MBA from Harvard and a master’s from MIT, so she went and built one. NextGen Jane, founded 2014 with Stephen Gire, developed a Smart Tampon System. You mail in the tampon, they read the reproductive tract. She has described a tampon as a singular access point to the reproductive system that you cannot otherwise reach without a biopsy. They went after endometriosis first, on the reasoning that ten percent of women have it and it takes ten years to name.

Valentina Milanova founded Daye in London in 2018 after her own experience with menstrual pain. Its diagnostic tampon for at-home HPV and STI screening has reached over 100,000 patients in the UK, and a Journal of Clinical Microbiology study found it as accurate as clinician-collected swabs, with fewer invalid results. Daye won Digital Health Rewired Pitchfest in March 2026, and Milanova’s message afterward was still about the UK falling behind on women’s health: research, funding, care.

Three companies. Three women who went looking for their own answer, couldn’t find it, and spent a decade of their working lives building the infrastructure that should have already existed.

Here is what a research gap costs, and it isn’t abstract.

It’s the appointment you rescheduled twice. The pain you described three times to three people and then stopped describing. The years you spent operating at reduced capacity while being told your labs were fine. The slow, expensive recalibration of a nervous system that learned it would not be believed and adjusted accordingly hyper vigilant in the doctor’s office, dismissive of your own signals at home, because the cheapest way to survive not being taken seriously is to stop taking yourself seriously first.

That adaptation is not a personality trait. It’s a nervous system doing exactly what it was trained to do by twenty years of evidence.

The correction isn’t optimism. It’s data. The pad works. The tampon works. The delay was never biological.

You were not a difficult patient. You were an unfunded research question.

Sources: The BMJ (2026); Journal of Clinical Microbiology (2025); Research (2025); Mathews Journal of Nursing review (2026); Annals of Medicine & Surgery (2026).

https://pubmed.ncbi.nlm.nih.gov/41638692/

https://qvin.com/

https://www.nextgenjane.com/

https://www.yourdaye.com/en-us/