Period blood could help diagnose diabetes and other illnesses

The first diabetes test based on menstrual blood was approved this year

A menstrual pad on a blue background

Earlier this year, the U.S. Food and Drug Administration approved the first health test based on period blood. It’s an at-home test for diabetes called the Q-Pad. Researchers are looking into what else menstrual blood can reveal about someone’s health.

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Doctors have several ways to test for disease. They might swab someone’s nose, collect their urine or draw blood for analysis. Menstrual blood has not traditionally been used in this way. But it might soon.

In January, the U.S. Food and Drug Administration approved the first health test based on period blood. The test is called the Q-Pad. It can be used at home. And it detects a substance in menstrual blood that can show if someone has diabetes.

Diagnosing this disease typically requires drawing blood with a needle. So some people may prefer to test their period blood instead.

Around 1.8 billion people worldwide menstruate. “Why let that go to waste?” says Sara Naseri. She’s a cofounder of Qvin, the company that makes the Q-Pad.

Naseri started to think that period blood might be an easy way to get clues on health about a decade ago. But back then, there wasn’t much research on the topic. So Naseri, a medical student at the time, decided to look into it herself.

That research has since shown period blood can indeed provide “essential health information,” she says. This includes red flags for diabetes. It might also include evidence of other ailments.

What’s in period blood?

Menstrual blood is far more complex than the blood that runs through veins or arteries. Technically, this material is called menstrual effluent. It’s made of cells and tissue from the thickened lining of a person’s uterus. It gets shed when they get their period. As a result, it does contain blood, just like you would get by drawing blood from elsewhere in the body. But it’s also full of proteins, hormones and bacteria found only in the uterus.

There may be other stuff in period blood too, says Kathryn Clancy. An anthropologist, she studies women’s health and medicine at the University of Illinois Urbana–Champaign. Research on menstrual blood, she says, is “so young that we’ve barely characterized everything that’s in it.”

Naseri and her colleagues wondered if substances in period blood could be measured like they can be in other blood samples. To find out, the team compared menstrual blood with blood drawn from elsewhere in the body. Those samples came from 20 women over two months.

It turns out that several substances can reliably be measured in period blood. That includes chemical markers of diabetes and inflammation. It also includes hormones that could help track someone’s health and diagnose problems.

Naseri’s team shared those findings in 2019. Further tests on using menstrual blood to diagnose diabetes led to the creation of the Q-Pad.

What is menstruation, exactly? TED-Ed explains.

The Q-Pad

Hemoglobin A1c blood tests reflect average blood sugar levels over the last few months. Usually these tests require a blood draw. But it can also be measured with the Q-Pad. Based on these data, it’s easy to tell if someone has diabetes.

The Q-Pad kit comes with two special menstrual pads. These have removable collection strips. A user wears the pads and allows the strips to collect blood during one menstrual cycle. Then both strips are mailed to a lab for testing. Results arrive via app or email.

“The reliability is excellent,” says Kathleen Jordan. And Q-Pad results match those from typical blood tests. Jordan is a doctor who specializes in women’s health. She’s chief medical officer of the telehealth provider Midi Health, based in Menlo Park, Calif.

a diagram of a menstrual pad shows that a collection strip containing blood can be removed from the center of the pad for testing
This diagram shows how collection strips can be removed from the Q-Pad for testing.Qvin

Diabetes can damage the eyes, kidneys, nervous system and heart. Estimates suggest that nearly 9 million people in the United States have diabetes but don’t know it. Many others have heightened blood sugar just below the level where diabetes can be diagnosed, Jordan says. Many risks can be avoided if the disease is caught and treated early.

“I think more people need to get tested, period,” Jordan says. The Q-Pad could help.

What’s more, many people with diabetes also have PCOS. That’s short for polycystic ovary syndrome. This condition causes irregular periods and infertility. By running the A1c test, Q-Pads could help diagnose PCOS as well as diabetes, Jordan says. But because the Q-Pad is new, she notes, doctors will likely retest patients with a typical blood draw to confirm its results.

Opportunities and open questions

For now, testing of period blood has been approved only for diabetes. But Naseri thinks it may have a far greater potential.

Menstrual blood could be used to measure a protein that signals inflammation, she says. Or hormones that offer clues to someone’s thyroid health. Or even antibodies that show how your immune system is responding to COVID-19. Doctors already test for all these things in standard blood samples.

And stuff in period blood that’s not found in other blood samples could lead to new types of tests. For instance, researchers have found substances in menstrual blood that are signs of infertility. Finding those substances usually requires imaging tests such as X-rays.

Cells in menstrual blood could help diagnose endometriosis, too. That’s a condition where tissue similar to the lining of the uterus starts growing outside the uterus. Diagnosing it usually requires a physical exam, ultrasound, MRI and sometimes even surgery. A period blood test would be much easier.

But many open questions need answers before period blood can be used for all these tests.

For instance, say a certain level of some substance is measured in period blood. Does that reflect how much of the substance has built up over time? Or does its amount in period blood rise and fall? Scientists need to study how period blood changes over time and between different people.

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Another challenge is how to keep menstrual blood samples fresh enough to test. Once blood is exposed to air, microbes start acting on it. There are ways to preserve blood samples drawn from veins or arteries. But menstrual blood breaks down faster.

The reason so many questions remain is simple, says Miriam Santer. “We’ve just not been focusing on women’s health.”

Santer cofounded theblood, a German company for testing period blood. “There’s not enough basic understanding of the woman’s body,” she says. That includes “how we’re affected by specific diseases, how we react to medication, therapeutics and so on.”

Talking about menstruation at all is still taboo for many, Santer adds. That stigma has been a major barrier to studying the basic bodily process. And that, in turn, has slowed progress in providing better health care to people with periods.

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