A period piece

Summary

Podcast Summary: Unexplainable – "A Period Piece"

Release Date: June 24, 2026
Host: Bird Pinkerton (Vox)
Main Guest: Dr. Gemma Evans

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Episode Overview

This episode explores a biological superpower hidden in plain sight: the endometrium, the lining of the uterus, and its remarkable ability to heal itself rapidly and without scarring during menstruation. Host Bird Pinkerton delves into the pioneering research of Dr. Gemma Evans, who investigates whether the unique properties of menstrual fluid (often stigmatized and overlooked) could be harnessed to accelerate healing in other tissues, potentially transforming wound care. Along the way, the episode examines why menstrual blood has been so neglected in scientific research and what possibilities might be unlocked if societal taboos were overcome.

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Key Discussion Points & Insights

1. The Super-Healing Endometrium (02:03–04:29)

• Standard Wound Healing: When you injure your skin, the process of healing—scabbing, cell multiplication, and restoration—takes about two to three weeks.
• Endometrium as Exception: The uterine lining (endometrium) is destroyed and rebuilt monthly, healing itself within just three to five days and, uniquely, without scarring.
  • Quote (Gemma Evans, 03:19): “It basically tells itself to be destroyed roughly every 26 to 35 days, but it also tells itself to repair.”

2. The Hypothesis: Menstrual Fluid as a Healing Agent (04:53–06:05)

• Dr. Evans theorizes that something in the menstrual fluid (the “super complex mixture” of menstrual blood) is responsible for the endometrium’s rapid healing and wonders if these properties could aid healing elsewhere in the body.
  • Quote (Gemma Evans, 05:49): “It seems really simple… you think, doesn’t this just make sense? …but not very obvious, because nobody else, surprisingly, had tried it. Maybe it’s the yuck factor...”

3. Lab Experiments: Wounds and Menstrual Fluid (06:05–08:56)

• Initial Tests: Using donated menstrual fluid, Evans and team applied it to skin cell cultures and observed remarkably fast wound closure.

  • Quote (Gemma Evans, 07:01): “We thought, what on earth has happened here? We clearly didn’t make the holes in the cell layer because we can’t find any holes.”
  • Findings: Adding menstrual fluid to artificial “wounds” healed them within 24 hours—the control groups healed much more slowly.
  • Quote (Gemma Evans, 07:33): “It was one of those eureka moments where you think, is this real?...”

• Further Testing: Applied to real skin samples (from surgery) and on pig skin (most similar to human skin for research).

  • Pig skin: Wounds checked every few days; still saw accelerated healing with menstrual fluid.

4. The “Ick” Factor and Practicality (08:56–09:47)

• Researchers recognize the practical and cultural challenges of using menstrual fluid directly for medical treatments.
  • Quote (Gemma Evans, 08:56): “People are not going to want to put menstrual fluid on their skin.”
  • Bird notes a brief history of “period blood facials” on TikTok, but both agree this isn’t a mainstream solution.

5. What’s In Menstrual Fluid? The Proteomics Investigation (11:30–13:22)

• Evans works with a proteomics lab to analyze what makes menstrual fluid unique compared to regular blood.
  • Quote (Gemma Evans, 12:21): “The proteomics team actually asked us, what’s this wacky second fluid you’ve given us? …We’ve never had a sample that has this level of complexity.”
• Discovery of unique proteins—potentially key to the accelerated healing observed.
• Early tests suggest individual proteins from menstrual fluid alone might have healing powers.

6. Barriers to Progress: Funding and Taboo (13:22–15:53)

• Funding Challenges: Biomedical research funding is scarce; reproductive health receives even less, and menstrual science is severely underfunded.
  • Quote (Bird Pinkerton, 13:32): “If you look at the numbers…15,000 research papers with references to semen and about 400 papers referencing menstrual blood.”
  • Historical Bias: Menstruation deemed taboo, largely ignored in research (especially with male-dominated science).
  • Quote (Gemma Evans, 14:34): “One thing I found very early in my research career was nobody else was talking about menstruation at scientific conferences.”
• Personal Outcome: Evans ultimately leaves the research due to lack of support, despite passion for the work.
  • Quote (Gemma Evans, 15:35): “I made that decision in the end to leave research…I loved, absolutely loved research. But getting that funding…it gets really hard at the end of the day.”

7. Changing Perspectives & Future Promise (16:15–18:03)

• Emerging Change: There’s growing recognition that menstrual fluid is a “treasure,” not trash. Increase in menstrual research in recent years, though progress is slow.
• Call to Action: Evans hopes her initial research will inspire others to continue—potentially revolutionizing wound care for burns, battlefield injuries, diabetes, and more.
  • Quote (Gemma Evans, 17:12): “I hope in the future somebody does pick it up and run with it…gaining treasure from the trash.”

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Notable Quotes & Memorable Moments

• On the uniqueness of menstrual fluid:
  “The proteomics team actually asked us, ‘what’s this wacky second fluid...?’ We’ve never had a sample that has this level of complexity.”
  — Gemma Evans (12:21)

• On societal taboos constraining science:
  “One thing I found very early…nobody else was talking about menstruation at scientific conferences.”
  — Gemma Evans (14:34)

• On research heartbreak:
  “It is mentally really challenging to walk away from that.”
  — Gemma Evans (15:56)

• On hope for the future:
  “I would hope that somebody would see the value in that and pick it up and run with it…the principle was gaining treasure from the trash.”
  — Gemma Evans (17:12)

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Key Timestamps

• [02:03] Comparison of skin and uterus (endometrium) healing
• [03:19] How the endometrium triggers destruction and repair
• [05:49] Why no one’s tried using menstrual fluid before
• [07:01] Eureka moment: holes in lab-grown skin close overnight
• [08:56] Practical barriers: “People are not going to want to put menstrual fluid on their skin.”
• [12:21] Proteomics lab: “We’ve never seen this level of complexity.”
• [13:32] Research funding stats: menstruation vs. semen
• [15:35] Gemma leaves research
• [17:12] Final hope and call to action

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Tone and Style

• The episode blends scientific curiosity with empathy and humor—acknowledging both the “ick factor” and the societal baggage attached to menstrual blood.
• The conversation is candid, open about research struggles and hopeful for change.

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Further Resources

• Featured books:
  • Period by Kate Clancy
  • Womb by Leah Hazard (with additional Q&A on Vox’s site)
• Thanks to specialists and contributors: Linda Griffith, Rachel Gross (author of Vagina Obscura), Lois Salomonson.

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This episode highlights how taboos and lack of funding can stifle promising advances in medicine, and challenges listeners to reconsider what is deemed “trash” in science—or in society. For listeners new to the subject, this conversation makes a compelling case that the mysteries of menstruation could hold profound benefits for everyone.

Transcript

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[Bird Pinkerton]

Let's say you fall off your bike and you hurt yourself. So the skin cells on your arm or your leg, for example, have been scraped off or torn apart and you're bleeding because the blood vessels underneath them are torn. How does your body heal itself? Well, first of all, the blood clots and forms a scab. And then once the scab forms, the very top layer of skin cells gets busy. The cells come in, they multiply and they basically quilt together underneath the scab to form a new top layer of skin. All of this over the course of about two to three weeks. And this trick that our skin can pull off, it seems pretty impressive until you compare it to a different part of the human body, this tissue that is of particular interest To a biologist named Gemma Evans, because it kind of turbocharges this entire process, this amazing tissue,

[Gemma Evans]

the endometrium, in the uterus.

[Bird Pinkerton]

The uterus, of course, is the womb, and the endometrium is its lining, the sort of safe, nurturing space for a fetus to hang out. So every month, the uterus builds the lining up, and then if no fertilized egg shows up, it flushes all that work away, kind of like sloughing off layers of skin. So the endometrium creates a wound, essentially.

[Gemma Evans]

It basically tells itself to be destroyed roughly every 26 to 35 days, but it also tells itself to repair. As soon as a piece of the uterus lining the endometrium starts to be shed, the section sort of next to it gets an instruct to start repairing it. That top layer of cells growing back happens as soon as an adjacent area has fallen off.

[Bird Pinkerton]

It heals not in two to three weeks like the rest of the body, but in three to five days. And usually it heals without scarring. So normally when the body does kind of a rush job like this, it has to make some sacrifices. It can build up scar tissue instead of regular skin, and that scar tissue can't always do what the original tissue could do. In the case of the endometrium, though, the repaired tissue is just like the original. This process is so quick and so impressive that it got Gemma and some of her colleagues thinking.

[Gemma Evans]

We thought, hmm, this is absolutely fascinating. What can this teach us about other parts of the body? Can we harness those properties?

[Bird Pinkerton]

If she could harness those properties, it could potentially help a lot of people. Diabetics whose wounds heal really slowly, people who have vascular diseases, even patients with burns. So this is unexplainable. I'm Bird Pinkerton, and this week, Gemma Evans tries to figure out if there's a way to translate the uterus's super healing powers to the rest of the body.

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Does your life change once a month because of your period? Oh, what a disaster. Let me tell it too straight.

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Unexplainable can change the way you feel about your period.

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You wouldn't think so, but it's wonderful. Fabulous. I call it just plain smart. Now, that's something.

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Remember, there's a feeling with unexplainable, it

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can actually change the way you feel about your period.

[Bird Pinkerton]

Going into all this, Gemma had a big hunch, because the healing that's happening in the uterus is happening while the uterus is bathed in menstrual fluid. This stuff that we also call Period blood that is basically sort of a super complex mixture of tissues and proteins and cells and other stuff. And so Gemma's hunch was that menstrual fluid might be what's helping the uterus heal so fast. And also that menstrual fluid could help other wounds heal faster, too.

[Gemma Evans]

That's essentially what we're looking at. It seems really simple, you know, you think, doesn't this just make sense? Like, isn't it obvious? But not very obvious, because nobody else, surprisingly, had tried it. Maybe it's the yuck factor, but that's the basic hypothesis of what we were doing.

[Bird Pinkerton]

To test this basic hypothesis, Gemma had to find some menstrual fluid. And because it's understudied, there wasn't an established protocol for collecting it as a fluid. But she found some volunteers who were willing to use menstrual cups and give her the contents.

[Gemma Evans]

The initial stage then, was to just test the theory. You know, would menstrual fluid actually have any effect on repair?

[Bird Pinkerton]

Gemma and her colleagues, they couldn't just go around putting menstrual fluid on people's wounds. So instead, they made a simplified version of a wound in the lab. They took cells from the top layer of human skin and then grew them in trays, and then they made a little hole in that quote, unquote skin to stimulate a wound and finally put menstrual blood on the holes.

[Gemma Evans]

The first time we did the experiment, we actually thought we got it wrong.

[Bird Pinkerton]

Gemma says they came back the next day and the holes were gone.

[Gemma Evans]

We thought, what on earth has happened here? We clearly didn't make the holes in the cell layer because we can't find any holes.

[Bird Pinkerton]

They hadn't made a mistake here. They really had made the holes.

[Gemma Evans]

It's just they'd repaired that quickly.

[Bird Pinkerton]

They wound up trying again.

[Gemma Evans]

We thought, okay, right, we've got to repeat this, but we'll look at them a bit more frequently.

[Bird Pinkerton]

And this time, it really was clear that something in the menstrual fluid was healing skin cells in less than 24 hours. Their control groups were healing more slowly, like it really was the menstrual fluid making the difference.

[Gemma Evans]

It was one of those eureka moments where you think, is this real? I just need to do it a few more times to actually check if it's real, because it doesn't feel like this can. It can be this simple.

[Bird Pinkerton]

Science can be kind of a frustrating process with a lot of dead ends, kind of unclear results. But this experiment was a pretty strong signal that, like, yes, this hypothesis was right on. But they still tried more experiments. Like they got real skin from plastic surgery patients to see how that healed. And they ran tests on living pigs as well. Researchers made 1 millimeter wounds on pig skin and then put menstrual fluid on those wounds.

[Gemma Evans]

Pigs are very similar to human when it comes to skin. It's why tattoo artists practice on pigs and they're the best or the most appropriate model for human equivalent skin research.

[Bird Pinkerton]

In these experiments, the results were not quite as dramatic. Like there wasn't the same kind of 24 hour turnaround time for healing. And especially in the pig experiments, they were only able to check the wounds every few days because the wounds had to be dressed. But once again, the researchers did find evidence that the menstrual fluid helped with healing. This was ideal. Like a bunch of experiments, lots of promising results. There's just one small problem.

[Gemma Evans]

To be completely frank. People are not going to want to put menstrual fluid on their skin,

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[Bird Pinkerton]

In the interest of fact checking, there was a TikTok trend for a while where people were using period blood is a face mask.

[Gemma Evans]

But regardless of vampire facials or whatever they're called, we're not going to get away from that ick factor.

[Bird Pinkerton]

And to be clear, like this ick factor makes sense, right? Like putting bodily fluids directly on your open wounds. Probably not the best idea. Which is why, as she was running these experiments on skin and pigs, Gemma's also working on another investigation, an investigation into how exactly menstrual fluid was working its healing magic.

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[Bird Pinkerton]

So Gemma Evans had seen that if you put menstrual fluid on wounds, they heal faster. And she also knew that putting menstrual fluid directly on wounds was probably not a real option.

[Gemma Evans]

So we started, I guess, actually trying to dig down and understand what's different about menstrual fluid. What's the actual, I guess, magic factors in the menstrual fluid that might be helping with this repair.

[Bird Pinkerton]

To figure this out, Gemma turned to a lab that does something called proteomics, where they basically analyze substances and tell you what kind of proteins are in them. And Gemma wanted this lab to tell her just a little more about the basic ingredients of menstrual fluid. So she gave them a bunch of normal blood as kind of like a baseline to compare to, and then she gave them some of the menstrual fluid samples that she'd collected.

[Gemma Evans]

The proteomics team actually asked us, what's this wacky second fluid you've given us? Because we've never seen this number of differences between two samples before. We've never had a sample that has this level of complexity.

[Bird Pinkerton]

Menstrual fluid, as it turns out, has way more going on than than normal blood running through our veins and arteries. It has lots of proteins that are not found in that normal blood. So Gemma picked a couple of proteins that seemed especially promising. She ran some more tests, and again, the results seem to suggest that some of these proteins, just on their own, might help speed up tissue repair. So these were more exciting results, like lots of promising ideas to pursue further. Except you can't find wound healing medicines based on Gemma's work out in the world today, in part because she didn't get to pursue these ideas further.

[Gemma Evans]

Essentially, it comes down to the funding environment. So Australia, us, globally, the funding environment is really, really tough.

[Bird Pinkerton]

If you look at the numbers for the NIH in the US for example, it only funds about 20% of the applications it gets for new research grants. And those are the numbers for all types of research. Science, like reproductive health, is especially underfunded within that, and then within reproductive health, menstruation science is extra ignored. Like, one paper I looked at found that over the span of a decade, There are about 15,000 research papers with references to semen and about 400 papers referencing menstrual blood. And like, the simplest explanation for this seems to be that historically a lot of scientists were men and they just didn't want to investigate menstrual blood because it was considered gross and kind of taboo or because they just weren't interested. So there hasn't been the same kind of scientific infrastructure and interest built up around menstruation as there has around other routine human processes. And Gemma says she saw this in her day to day.

[Gemma Evans]

One thing I found very early in my research career was nobody else was talking about menstruation at scientific conferences.

[Bird Pinkerton]

Even now, to be clear, when she reflects on her efforts to get more funding for this particular project, Gemma does not think that, like some Australian funding panel got the ick from, from menstrual fluid and refused to fund her work because of it. She says that skin treatments were especially hard to get funded and that was probably part of the problem. And also she thinks that just the idea of using proteins from menstrual fluid was maybe just too new.

[Gemma Evans]

Getting funding to progress the research for something which was entirely novel. Nobody else had ever done this before. Even though we had a wealth of data to support support us. It was almost a leap too far for funding bodies because this was very

[Bird Pinkerton]

blue skies as it was. Gemma and her colleagues looked for funding in a bunch of different places, couldn't find it.

[Gemma Evans]

And then I made that decision in the end to leave research. I loved, absolutely loved research. It was amazing. But getting that funding to pay your salary, pay the salary of your team and pay for the research itself, it gets really hard at the end of the day. And I think that's why we lose a lot of good researchers.

[Bird Pinkerton]

She does clinical trial work now instead.

[Gemma Evans]

You know, anybody who's in research, and particularly biomedical research, where the ultimate goal for biomedical research is to improve people's lives. That's why we do what we do in biomedical research. It is mentally really challenging to walk away from that.

[Bird Pinkerton]

I don't want to end on total doom and gloom though, especially because things are kind of changing around menstruation. And menstrual fluid. Like, as I was reporting out this story and talking to people, they kept saying that, yes, menstrual fluid has been seen as trash historically, like, something to be disposed of. But in the last decade or so, people have started doing a lot of really cool, really interesting menstrual fluid research. People are realizing that menstrual fluid is kind of a treasure. And sure, like, progress is slow and this particular example of promising research hit a funding snag, but this doesn't have to be the end of the story. Like, even if Gemma isn't the person who pursues this, she has put the initial research out into the world, and now maybe someone else out there can keep exploring where she left off.

[Gemma Evans]

I hope in the future somebody does pick it up and run with it, because I think there is some significant opportunities there for, you know, not necessarily someone who's just fallen over and grazed their knee, because what school child hasn't done that? But somebody who has an extensive burn wound or is in the military and is injured in battle and needs to heal a wound very, very quickly. Somebody who has a health condition which makes them more likely to have an infection in a wound or more prone to wounds, full stop. I would hope that somebody would see the value in that and pick it up and run with it. And, you know, I think the whole overarching principle of what we were doing was, was gaining treasure from the trash.

[Bird Pinkerton]

This episode was produced and reported by Me, Bird Pinkerton. It was edited by Jorge Just and Brian Resnik. Meredith Hodnot runs the show. Noam Hassenfeld composed the music. Christian Ayala did the mixing and the sound design. Melissa Hirsch did our fact checking. And Manding Nguyen is the fact that loggerhead shrikes impale their prey on little spikes and save it for later. If you want to read more about periods before then, though, I have two book recommendations. The first is Kate Clancy's book Period, which talks about Gemma's research and so much more. And then the second is Leah Hazard's womb. I actually first heard about Gemma's research in Leah's book and I spoke to her about it. And also about other exciting period science. We have a Q and A on the site from that conversation. Thanks also to Linda Griffith, who took some time to talk to me about this science, and to Rachel Gross, the author of Vagina Obscurity Gura, who helped me think through this episode. And finally, a huge, huge thank you to Lois Salomonson, who used to run the lab that Gemma worked at and just took a lot of time to help me understand this story. If you would like to support the show and the journalism that Vox does, we would love it if you would become a member. It is very easy to do. Just go to Vox.com members and and you will get access to all of Vox's journalism. But you will also know that you are supporting all of Vox's journalism. And for those of you who have emailed to let us know that you signed up because of Unexplainable. Thank you. And thank you to those of you who have left us a nice review on your podcast platform or told someone in your life about the show. You are all excellent. Unexplainable is part of the Vox Media Podcast network and we will be back very soon with another episode about everything that we do not yet know.

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