Endometriosis affects 190 million people worldwide – or a tenth of women of childbearing age – who suffer from heavy periods, excruciating pelvic pain, bladder or intestinal problems, and even infertility. Worse still, it usually takes five to 12 years to get a diagnosis. Confirmation requires laparoscopy, a medical procedure that involves inserting a small camera into the pelvic cavity, explains Ridhi Tariyal, co-founder and CEO of NextGen Jane, a biotech start-up.
This is why the latter, accompanied by other start-up managers, decided to develop a better diagnosis using a test. This promises to be faster, less expensive and less invasive than surgery, and could reveal much more than just the diagnosis of endometriosis. According to them, it would be enough to analyze menstrual blood, reports the BBC in an article.
While urine, stool and blood tests are regularly used in the medical field, this is not yet the case for menstrual blood. However, it is a considerable source of information: half is composed of ordinary blood, while the other half contains proteins, hormones, bacteria, endometrial tissues and cells from the vaginal cavity, the cervix, the fallopian tubes and even the ovaries.
“Access to cell types and other molecular signatures that are simply not found in whole blood, saliva or other sample typesexplains Ridhi Tariyal. In essence, it is a natural biopsy that provides information about the reproductive organs.»
385 proteins present
“(Menstrual blood) can be used to look for all conditions that affect the uterus – and there are many.“, explains Christine Metz, reproductive biologist at the Feinstein Institutes for Medical Research at Northwell Health, in the United States. The researcher has been studying menstrual blood for more than ten years to identify biomarkers of endometriosis.
She would now like this bodily fluid to provide clues to cure diseases such as endometrial cancer, adenomyosis (when the uterine lining grows into the uterine wall) or endometritis (persistent inflammation of the endometrial lining).
“Menstrual secretions are very valuable for understanding uterine health, information we cannot obtain any other wayexplains Christine Metz. This is a very unique biological sample.” One study identified 385 proteins found exclusively in menstrual blood.
There is also another major benefit of menstrual blood, that of providing a more comprehensive view of uterine health, unlike the small sample of tissue taken during an endometrial biopsy. “The uterus is about the size of a grapefruit, so an endometrial biopsy does not provide an overall assessmentadds the researcher. However, menstrual blood corresponds to the entirely eliminated endometrium.»
To date, NextGen Jane teams have identified a few markers that could reliably distinguish endometriosis from healthy infertile women. A study carried out in the United States among hundreds of women with endometriosis is currently underway to confirm these results, explains Ridhi Tariyal. In May 2025, NextGen Jane received a $2.2 million (€1.9 million) grant to fund the clinical validation of a menstrual test to screen for endometriosis in infertility patients.
