Why don't we know the amount of our own menstrual blood?

From "Unclean" to "Valuable": The Transformation of Menstrual Blood, Woven by Technology (Part 1)

— Emm: The Quiet Questions Posed by the World's First Smart Menstrual Cup

1｜A Slight Unease

One of the things that sparked my interest in Femtech was a menstrual cup that emerged from Korea in 2017.

That menstrual cup, called LooonCup, was a product conceived with a sensor embedded in the cup itself, capable of detecting leaks and measuring body temperature.

"Is that even possible?" At the time, I was amazed by the "idea itself."

The reason for my surprise was less about the technical aspects and more about something simpler. The very idea of treating menstrual blood as something to be "measured" was new to me.

For a long time, menstruation has been treated as "unclean" in many parts of the world. In Japan, there were once places called "seiri-goya" (menstruation huts) where menstruating women were isolated. Even today, bins for sanitary products are often called "obinutsu-ire" (waste receptacles for bodily fluids).

Because it's "unclean," it's avoided. It's disposed of as waste, and no records are kept. No one ever thought to measure that blood.

The problem wasn't menstruation itself, but rather the layers of cultural and social preconceptions wrapped around it.

2｜The Structural Issue

Menstruation has long been relegated to the "private sphere."
Little data has been accumulated, either on the medical side or by individuals themselves.
Monthly blood loss. How many days it lasts. What causes it to change.

Simply marking "first day of period" on a calendar actually obscures a lot of information.

And this "lack of visibility" has often been used as a basis for judging something as "not abnormal." What isn't measured rarely makes its way into medical discussions, workplace system design, or policy debates.

"You have symptoms, but there's nothing wrong on examination."

Between these words, repeated countless times in consulting rooms, many people's experiences have quietly slipped away. It's not anyone's fault. It's due to a structure built on the premise that data "doesn't exist."

3｜The Meaning of Measurement

From a public health perspective, addressing something as a societal issue first requires a "baseline."

What is considered "normal" within a population? How much deviation from that baseline should be seen as a "change"? There was no such standard for menstruation until now. A gap existed right in the middle, between "individual sensation" and "medical test values."

I believe Emm, originating from the UK, is gradually trying to fill that void from the extension of daily life.

It has successfully commercialized the world's first smart menstrual cup. It's made of medical-grade silicone with a tiny sensor embedded within it.

Little special effort is required. There's no need to open an app every day or constantly translate one's feelings into words. The structure is such that data measured close to the body is later returned to the individual.

Another important design point to remember is that data transfer only occurs when the cup is outside the body and placed in its charging case. When it's inside the body, it does not communicate externally.

Balancing "measurement" and "privacy" will be a recurring theme for femtech. Emm's design already offers one way to answer that question.

4｜My Thoughts

I believe that measuring is not an act of control over oneself.

It's about being able to treat one's body with a slightly finer resolution. Not data to incite anxiety, but data to increase the room for judgment.

"I feel like my flow is heavier than usual" can become "My flow is X mL heavier than usual." Just that change can slightly alter the quality of conversations with doctors, and with oneself.

And another important thing is that "my data" doesn't end with just me.

If individual records accumulate, they will eventually become the basis for research, the blueprint for systems, and a reference for decisions in someone's consulting room. The story of an individual body and the story of societal structures are continuous.

For us, introducing a product like Emm to Japan means more than just "selling a product." It's akin to the work of recontextualizing this "continuous part" within the Japanese context.

Japan's medical system. Working styles. Sex education in schools. Conversations at home.

What will change when the premise of "menstrual data exists" becomes commonplace in each of these areas? I believe the discussion about social implementation starts there.

Menstrual blood, once treated as "unclean," is quietly transforming into "information" to speak about individual health. I interpret the change that technology is now beginning to weave as precisely that.

5｜A Quiet Question

Once measurement becomes commonplace, what kind of relationship will we re-establish with our bodies?
How many stages will we be able to place between "not abnormal" and "healthy"?

The answer is not yet here.

— Dr. Amina Sugimoto, PhD in Public Health (London School of Hygiene & Tropical Medicine) / Founder of fermata Inc.