A movement for women's health

Medicine was made for men. Together, we're changing that.

Women's bodies are still poorly understood: our cycles, our hormones, how medicines work for us. We are bringing women together to build the knowledge that is missing. It starts with something almost every woman has: her period.

Why it matters
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Why

Women were left out.

For decades, new medicines were tested mostly on men. Women were then given the same medicines anyway.

1993
Until this year, US rules kept women who could get pregnant out of early tests of new medicines.
US FDA guidelines, 1977 and 1993
2×
Women get side effects from medicines nearly twice as often as men.
Zucker & Prendergast, Biology of Sex Differences, 2020
½
Half the dose: in 2013, a common sleeping pill was found to be too strong for women. Their dose was cut in half, after more than 20 years on the market.
US FDA, 2013
1.5%
Only 1.5% of mammal species have periods. Lab mice and rats don't, so the usual lab research can't show how periods work.
Bellofiore et al., American Journal of Obstetrics and Gynecology, 2017
<1%
Less than 1% of health research money goes to common women’s conditions like endometriosis, PMS and menopause.
World Economic Forum, 2025

The result: women spend a quarter more of their lives in poor health than men.

World Economic Forum and McKinsey Health Institute, 2024

Why period blood is special

What science already knows makes it worth collecting.

It stays liquid
Period blood has already clotted inside the womb, and the womb lining has broken it down again.
Cederholm-Williams et al., Journal of Clinical Pathology, 1984
It heals without scars
The lining of the womb breaks down and rebuilds itself, up to about 400 times in a life. No other tissue in the adult body does this as a normal routine.
Maybin & Critchley, Human Reproduction Update, 2015
It repairs itself fast
The repair starts while the period is still going on. Within a few days, the inside of the womb is closed again.
Evans et al., FASEB Journal, 2019
It carries living cells
Period blood holds living cells from the lining of the womb and from the immune system.
Shih et al., BMC Medicine, 2022
Data

Better medicine starts with data. For periods, there is almost none.

Research can only answer questions it has data for. Periods have barely been measured.

5*
periods in a row. That is the most any study has collected from the same women, as far as we know.
Isala LUNA study, University of Antwerp, 2024
~100*
women took part in that study. Most studies on period blood are just as small, or smaller.
Isala LUNA protocol; Period Foundation evidence review, 2026
0*
large collections that follow the same women's periods over a whole year, as far as we know.
Period Foundation evidence review, 2026

* For liquid period blood. Studies with dried blood on pads or strips are bigger. The UK CycleTrack study, for example, has thousands of women, but follows each of them for 3 periods.

Our vision

The world's largest bank of menstrual blood.

Thousands of women. A sample from every period, year after year. Kept safe, controlled by the women who give them, and open to research that helps women.

First
Vienna
The first women, 12 periods in a row.
Then
More cities
Partner labs across Austria, also in smaller cities.
Next
Europe and beyond
One shared bank, many places, the same rules.

Every month, period blood is thrown away. It could help research.

Period blood contains cells from the lining of the womb. Collected over many months, it becomes knowledge that has never existed. Building it is our job, together, for the good of all women.

The movement

No one will close this gap for us. So we do it together.

Around the world, women, scientists and doctors are starting to close the gap. We want to bring them together, and to give every woman a way to take part.

Every woman who takes part, supports or simply spreads the word helps build the data women have been missing.

How it will work

Simple for you. Useful for research.

Step 1
Collect at home
During your period, you collect a small sample at home. We give you everything you need.
Step 2
Drop it off nearby
You bring the sample to a partner pharmacy close to you.
Step 3
Stored safely
A partner lab stores the sample for research, without your name on it.
Step 4
Research learns
With samples from many women over a whole year, researchers can finally see patterns.

We will start with a small group of women. Details follow once the study is approved.

Your say

Your sample. Your say.

The samples are looked after by a non-profit association. The women who take part have a say in what they are used for.

You choose
You decide what your sample may be used for.
Your name stays private
Your name is kept apart from your sample. Researchers never see who you are.
Never for ads
Your data is not used for advertising.
Leave any time
You can stop whenever you want, without giving a reason.
Marine Popoff
Marine Popoff
Founder
Why I started this

"AI is about to change medicine, but it can only learn from the data that exists. For women, most of that data was never collected. So AI learns from men.

I've spent years in biotech and finance, watching where the money and data go. Women's health gets neither. No one has fixed this because it isn't easy, but it has to be done.

I can't promise a cure for any disease. But a woman who gives samples today and falls ill ten years from now may find that what we stored helps find answers, for her or for women like her. And every sample makes the world a little better.

What I can promise is how we do it: as a non-profit, with medical researchers, funded by public money. What we learn belongs to everyone. And no woman's data is ever used without her say.

We will publish what we find, including what doesn't work. Women have been promised a lot. Let's gift our daughters a world where medicine knows their bodies."

Join the movement.

Everyone who joins before the first study starts is a founding member. When the study begins, we ask you first.

Signing up doesn't commit you to anything.
We won't ask about your health here.
You can leave the list any time, with one click.
Be the first founding member.
Founding members

The first founding members will appear here.

Doctor, researcher, pharmacy or supporter? Write to us: hello@period.foundation

Would you like to take part in the study?
Can you also help with your work? Optional. We'll get in touch.

Then spread the word with #MyPeriodCounts.

We'll send you an e-mail to confirm. Only then are you on the list.

Questions

Can I take part already?
You can sign up now. The study itself first needs approval from an ethics committee. We'll write to you when it starts.
What does it mean to be a founding member?
Everyone who signs up and confirms their e-mail before the first study starts is a founding member. You stand behind the idea from the very start, and when the study begins, we ask you first. It is a pledge of support, not a contract: it costs nothing, you get no shares or money, and you don't have to give samples.
Do I need to have period problems to help?
No. This is for every woman. Research needs women with and without symptoms.
Is this a medical test?
No. It is research, not a check-up. You will not get personal test results or a diagnosis.
Does it cost anything?
No. Taking part will be free.
Who is behind this?
Period Foundation is the brand of "Period – Verein zur Förderung der Menstruationsforschung" (in Gründung), a non-profit association being set up in Vienna. It was founded by Marine Popoff, who chairs it.