Podcast Host:
Lisa Hendrickson-Jack is a certified fertility awareness educator and holistic reproductive health practitioner with over 20 years of experience teaching fertility awareness and menstrual cycle literacy. She is the author and co-author of two widely referenced resources in the field of fertility awareness and menstrual health — The Fifth Vital Sign and Real Food for Fertility — and the host of the long-running Fertility Friday Podcast. As the founder of the Fertility Awareness Institute, Lisa’s current clinical focus is her Fertility Awareness Mastery MentorshipTM Certification program for women’s health professionals.
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Episode Summary: Why Your Menstrual Cycle Is Your Fifth Vital Sign
In this solo episode celebrating the sixth anniversary of The Fifth Vital Sign, Lisa Hendrickson-Jack revisits one of the foundational concepts of her work: the argument that the menstrual cycle deserves to be considered a true vital sign — on par with heart rate, blood pressure, respiratory rate, and body temperature. Lisa breaks down what a healthy menstrual cycle actually looks like across each of its phases, from the true menstrual bleed through the pre-ovulatory phase, ovulation, and the luteal phase, and explains how deviations from normal parameters can signal underlying hormonal or health issues. The episode also addresses the frequently misunderstood distinction between a true menstrual period and a hormonal withdrawal bleed, including the little-known history behind why the 28-day pill cycle was designed the way it was — not for medical reasons, but for marketing. Lisa shares reader reviews of The Fifth Vital Sign and reflects on why menstrual cycle education remains one of the most powerful tools for improving women’s health literacy. This episode is an essential listen for anyone new to fertility awareness and a meaningful revisit for longtime listeners.
Listener Takeaways for Charting Your Cycle And Reading Your Body’s Signals
- Your menstrual cycle is already sending you information — charting is simply the act of learning to receive and respond to those signals before minor imbalances become significant health issues.
- A true period is defined as bleeding that follows an ovulatory event by approximately 12 to 14 days; bleeding that occurs without ovulation is an anovulatory bleed and carries a different clinical meaning.
- Period pain that requires medication to manage is common but not optimal — elevated prostaglandin levels are associated with higher-than-normal inflammation, and this is worth investigating rather than suppressing.
- The withdrawal bleed that occurs on the pill has no medical basis; it was designed purely to make the pill appear more natural and maintain user acceptance in the 1960s — it is not the same as a true menstrual period.
- Understanding the menstrual cycle as a vital sign is relevant for every woman regardless of whether she is trying to conceive — cycle health is whole-body health.
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Full Transcript: Episode 558
Lisa Hendrickson-Jack:
This is the Fertility Friday podcast, episode number 558. Welcome to today’s episode. In today’s episode, we are going to be focused on the topic that I have been talking about since the beginning of this podcast, which is that we should be considering our menstrual cycle as a vital sign. And we’re going to talk about what that means, why that is. And of course, today’s episode is in celebration of my first book, The Fifth Vital Sign. This week marks the sixth anniversary. It is wild to consider that this book has been out for six years. So I’m also going to share some fantastic book testimonies that were shared on Amazon, and we’re going to jump in and get into the nitty-gritty. So without further ado, let’s go ahead and get started.
So I want to start with the question, what is a vital sign? When I’m interviewed on other podcasts, often this is the first question that I’m being asked. And a vital sign is simply a tool that we use to measure how the body is functioning. And some of the most common vital signs that are measured are things like our heart rate, our respiratory rate — how many breaths we take each minute — our blood pressure, and even our body temperature. Now when I argue that our menstrual cycle is the fifth vital sign, I’m essentially saying that just like those other measures, whether it be our blood pressure or our respiratory rate, the menstrual cycle, when we look at it in its entirety — so sometimes when I say menstrual cycle, especially for those who are not as deep into the fertility awareness world as our Fertility Friday listeners, they may think that I’m just talking about the period itself. But of course, when I talk about the menstrual cycle, I’m talking about all the things that are happening from the first day of your period, the first day of your true bleed, all the way up until the day before your next one.
So we can get really deep into those menstrual cycle characteristics and identify not only what’s normal for the period, but what’s normal for the whole cycle. So when we break down what’s happening in your period, what’s happening as you approach ovulation with your cervical mucus patterns, with the duration of time — so how long it actually takes you to reach ovulation — when we look at the period of time between ovulation and your next period, the length and quality of your luteal phase, we can really break down the cycle into its different phases and identify what is normal for each of those phases and even look at some of those different parameters. And when we do that, we really can use the menstrual cycle as a vital sign similar to the other measures. And the reason is because your menstrual cycle is happening in real time and it is sensitive to the different changes that are happening.
So for example, if you’re having a stressful week and it just so happens that that stressful week is happening around the time that you’re approaching ovulation, many women will find that sometimes their ovulation is disrupted or delayed. Similarly, if you are experiencing a stressful event after you’ve ovulated, sometimes we find that that has an impact on the luteal phase. Maybe it makes the luteal phase a little bit shorter, or maybe you notice a little bit of spotting before your period, or maybe you notice that your PMS symptoms have ramped right up. And this is how we can start to understand how much our menstrual cycle is intertwined with whatever is happening in our lives.
And when we look at specific health issues — whether it’s something like insulin resistance, like is common in PCOS, or whether it is painful periods — and we’re noticing that we’re having pain and certain symptoms at certain times of the cycle, when we start to pay attention to the menstrual cycle and start to see the cyclical nature of some of our symptoms, it can give us a much greater insight into what’s happening and can notify us as to whether or not some of those symptoms are hormonal. So when I’m talking about using the menstrual cycle as a vital sign, it’s already there. Our menstrual cycle is already providing that information. It’s just that now that we know, we have the opportunity to tap in and pay attention.
I always say that your body can’t talk to you in words. It can’t send you a text message or give you an email. But what it does do is it gives you symptoms. And our job is to actually pay attention. So when we start charting our menstrual cycles, we are now active participants in this process. Before, it was still happening. Your body was still sending you messages. But when you start to chart your cycles, you are now tapping into those messages and you are able to respond. And another thing that is worth considering is that if you don’t listen to your body when it whispers at you, eventually those whispers turn into screams. And so if you think about any time you’ve had a symptom — your foot’s kind of sore or whatever — and you just ignore it, and then eventually it turns into this really big problem, that is what we want to avoid. And when we start to pay attention to our menstrual cycle as a vital sign, we can start to get so in tune with what we’re seeing and what it means about our situation and our habits that we can address those symptoms when they’re still whispers before they become big problems.
So let’s dive into what a normal menstrual cycle looks like. For some of you, this is going to be a review. But for some of our newer listeners, this might be the first time that you’ve heard someone break it down to this level. So again, when we’re looking at the menstrual cycle, I’m not just looking at the period, but we can start at the period. I had mentioned that we consider the first day of your menstrual cycle to be the first day of your true bleed. So it’s not uncommon for many women to experience bleeding leading up to their period — some spotting or things like that. But if you’ve had a period before, you’ll know that there’s a certain point when you actually start to bleed and you start to flow and you need to get something to take care of that flow, whether that be your pads, tampon, or menstrual cup. And so that first day of your true bleeding, when you start to flow, that is the first day of a true menstrual period. And although it’s very common to have that spotting leading up to it, I would say that that falls outside of what we would consider optimal.
So a healthy normal period lasts around an average of about five days or so, and typically that range is between about three to seven days. So if your period is lasting like a day or two, well, first of all, we have to confirm that it’s actually a true period. And we define a true period as bleeding that comes about 12 to 14 days after an ovulatory event. It is possible to bleed — even to bleed in the sense that it lasts for a few days and looks like a period — without ovulation. And we would call that an anovulatory bleed. But typically, the only way to identify if your cycle is truly ovulatory on a regular day-to-day basis would be to chart your cycle so that you can confirm if ovulation took place before that bleed that you’re experiencing.
So a healthy cycle falls somewhere into those parameters — about three to seven days, with an average of about five days. We would expect your period to be red. We would expect it to start moderate to heavy and then gradually taper off. And although it’s normal for women to experience clotting, we wouldn’t want to consider big, large clots to be normal or optimal. So we want to be aware that those, although common, would fall outside of what we could consider optimal. And the same thing goes with pain. And whenever I talk about pain, there’s always someone who says, “Well, it’s normal to have pain.” Well, it’s very, very common. Many women have pain with menstruation. But I would argue that anything beyond mild to moderate pain that requires the use of medication, although very common, we shouldn’t consider that to be optimal. Because what we know about painful periods is that women who experience painful periods do have higher levels of inflammatory markers such as prostaglandins. And I cited a study in The Fifth Vital Sign that showed that women who had higher levels of pain had upwards of four times the levels of prostaglandins — those inflammatory markers — compared to women who did not have period pain. So we know that if you’re experiencing moderate to severe pain, you have a higher level of inflammation. And that’s an opportunity for you to address that and see what we can do to bring that down. And so in The Fifth Vital Sign, there is a whole chapter on your menstrual period so that we can break down exactly what it is, what’s happening there, how it’s a natural inflammatory process. And if we think about it that way — the research defines it that way — if it’s a natural inflammatory process, then it makes sense that if that process goes awry, that is when we start to see some of those negative symptoms that are not ideal.
So as we go past the period, one last thing I want to say is that a period should be like a sentence. It should have a beginning, a middle, and an end, and then it should be over. And so when we’re looking at what would be normal within that period, if you are continuing to bleed for eight, nine, ten days after your period was supposed to stop, or if your period is starting again five days later, you’re bleeding around ovulation, you’re bleeding before you have your next period — that is not considered to be optimal, although many women do experience mid-cycle bleeding or spotting.
So as we go then past the period into that pre-ovulatory phase, what we would consider to be normal and optimal would be to have several days of cervical fluid leading up to ovulation. We’re looking at anywhere from about two to seven days of mucus prior to ovulation, and at least one of those days — if we’re looking at what would be optimal — we should be able to observe clear, stretchy cervical mucus looking like clear, raw, stretchy egg whites, at least one day, and to see it a few times that day — that would be considered optimal. But cervical mucus can look like creamy white hand lotion, and it can also look like this clear stretchy cervical fluid. Now, again, it’s not uncommon for women to have less mucus. Many of my clients don’t necessarily have optimal mucus, especially if they’ve had an extensive history of hormonal contraceptive use, or if they’ve had a history of cervical dysplasia, or if they’ve had cervical procedures to remove abnormal cells. But typically, when we’re seeing less than optimum mucus, there is a reason for it. So again, going back to the concept of the menstrual cycle as a vital sign — if we know what those normal parameters are, then we’re better able to identify if there could be an issue.
To continue: ovulation has to happen in a normal healthy cycle. A normal healthy cycle can range typically between about 24 and 35 days. So in order to get your cycle within that normal range, ovulation typically would be taking place somewhere between days 10 and 22. So the average cycle is about 29 days, with ovulation around day 15. Ovulation could be happening within that range in order to have your cycle fall within that normal healthy range.
So after we have ovulated, we would expect a couple of things to happen. The first thing is that we would expect to see our cervical fluid dry up for the most part. Again, it’s not uncommon to see some mucus kind of lingering as you ovulate and your progesterone levels rise. So I wouldn’t say that every woman is to expect to have completely dry for the whole rest of the cycle. But we do expect to see either the cervical mucus go away completely or significantly reduce. And the last thing I’ll say about that second half of your cycle — the post-ovulatory or luteal phase — is that in a healthy cycle, we would expect that to last for about 12 to 14 days.
So now I’ve taken you through what a normal cycle looks like. When we consider the menstrual cycle as a vital sign, we can think of all those different aspects of the cycle, and within each of those, we can start to identify what’s healthy and normal. And this is how we put this concept of the vital sign in action. If we look at the total length of the cycle — well, if your cycle is 45 or 50 days, that is telling us something. Not just that there’s something wrong, but typically women who are having these long and irregular cycles, it narrows down what could be the reason. We often see that in PCOS, which is associated with insulin resistance and elevated androgen levels. We sometimes see that in times of severe stress if it’s situational. And it can also be associated with certain inflammatory conditions, or over-exercise and undernutrition if it’s still in the middle of what we call the HA spectrum.
We can look at cervical mucus patterns. We know that in a normal healthy cycle, we should see cervical fluid leading up to ovulation. We shouldn’t see it every single day, and we shouldn’t have a whole cycle where we don’t see it at all. So in either of those situations — if you’re seeing some sort of discharge every single day, that could notify you of something as basic as an infection. If you’re seeing no mucus whatsoever, that can also give us information about whether you’re ovulating or not. So if you’re ovulating and you’re not seeing mucus, that can give us an idea that maybe we need to look at whether you’re taking medication that could be suppressing your mucus production, or whether your hormone level isn’t optimal and it’s not triggering mucus production even if you are having enough to ovulate. And so again, when we look at the menstrual cycle as a vital sign, we can gain a lot of valuable information.
So whenever I dive into these topics, I inevitably get questions about the birth control pill, because I feel like our modern experience of fertility awareness methods is often linked to our experiences with hormonal birth control. Many women have negative experiences with hormonal birth control, and that is what can lead them to look for alternatives. And when we talk about the difference between a true menstrual period and a withdrawal bleed — a pill period — inevitably the question has come up more and more lately: do we even need to have periods?
So you may have heard of this argument before — that women who were back in the day, many thousands of years ago, didn’t have as many periods as we do today because they were having more children. And so often this argument is made that we don’t really need to have periods anymore, or it’s totally okay if we suspend them because we’re having too many periods now because we’re not having as many children. So that’s something I wanted to talk about, because the whole logic, as far as I’m concerned, is completely flawed. Because the solution to this “period thing” is to put women on the pill and just have them take it continuously — and to argue that this is like natural, like when women used to have lots of babies, is completely psychotic, because the main issue is that if you are taking hormonal birth control to suppress ovulation, that is not a natural state. When you’re pregnant and you are growing a baby, your body is releasing hormones that naturally suppress ovulation — higher levels of your natural estrogens and your natural progesterones together — and that is suppressing the ovulatory events from happening. That is not the same as taking a synthetic hormone. Whether it’s a synthetic estrogen formulation or a synthetic progestin formulation, that is not the same as your natural hormones. It does not have the same effects as your natural hormones, and you’re not pregnant, so it’s not a natural state.
And when we look at the data, when you’re taking hormonal contraceptives, you still continue to produce a low level of your natural estrogen and progesterone. But the levels are low and they’re very state-like — they’re consistently low. And the only natural state that is similar to that, where you have this low, consistent production of your natural estrogen and progesterone, is menopause. So really and truly, we can’t compare the state that we are in when we’re on hormonal contraceptives to the state that is natural, like pregnancy. It’s a complete myth and it’s totally flawed logic. And to say that it’s totally okay for women not to have periods — just put them on the pill and that’s the same thing as if they were in the ancestral category of having lots of babies — it’s just preying on the fact that we haven’t been taught how our bodies work.
So the truth is that when we’re on hormonal contraceptives, it’s an influx of artificial hormones that suppresses ovulation altogether. When we’re taking artificial hormones, we don’t have a cycle. And that is not a period. If you are on the pill or the patch or the ring or any of those typical combined synthetic estrogen-progestin formulations, it is most closely putting your body into a state that’s kind of like menopause — kind of like an artificial, temporary, chemical menopause. And then if you think about some of the most common side effects of birth control, like depression and low libido and sexual issues like low sex drive, all of a sudden it makes sense. That’s why you have 20-year-olds that have vaginal dryness because they’re on the pill. Makes sense now. So from that perspective, I would say that we do need periods. There’s not necessarily a scientific reason to have those pill bleeds — if that is the question.
I think that this whole line of thinking is really interesting. To have manufacturers of these drugs come out and say that we don’t really need to have periods — because then the solution is continuous use of these artificial hormones — that really affects their bottom line. They can argue that it’s convenient and they can even argue that it’s natural. But ultimately, it takes us back to how the pill was developed initially. This is a story that I shared in The Fifth Vital Sign and I shared a brief discussion of this also in Real Food for Fertility.
So the first pill came on the market in 1960. It was called Enovid. And in the years leading up to the release of this drug, they did what I would call a beta trial. Prior to Enovid coming on the market, there was no hormonal birth control. None of these women who were living in the ’50s would have had any experience with anything like this. Prior to the pill coming out, the only time a woman would have had the experience of not having her period would be if she was pregnant, or if she was ill, or any other kind of natural state that would coincide with not having a menstrual period.
So they took these women before they released this drug and did a trial, and many of these women were actually trying to conceive. The first pill formulation was actually a continuous formulation — it wasn’t organized into 28-day intervals. They just gave it to them continuously. And so these women just stopped bleeding, because of course the pill suppresses ovulation and you just don’t bleed. So they thought they were pregnant, and the researchers were kind of like, “No, no, no, you’re not pregnant, it’s the pill.” But they couldn’t understand, because there was no precedent for this in the ’50s. And the women eventually figured it out after the researchers continued to explain that it was a medication. But they became very upset about this, because many of them had been trying to conceive. And of course, it’s very upsetting to think that you’re pregnant only to discover that you’re not.
So out of this situation, we got the modern-day pill. The researchers had this brilliant idea to put the pill in 28-day formulations — to give the synthetic hormones for a duration of time, and then to take them away for a few days so that you get a bleed. And that way, the artificial pill cycle would mimic the true menstrual cycle. And it would kind of be like a security blanket — we would kind of think that it’s the same. And that was how they came out with Enovid, the first pill, and kind of ran with it. And so there was never a medical reason for them to induce this fake bleed. It was always just to kind of make it seem more natural and to dupe women into thinking it was the same thing as not being on the pill, except they couldn’t get pregnant.
And so now, many, many years later — decades later after this initial formulation came out — now the marketers for these big drug companies are coming out and saying, “Well, there’s no reason for a bleed.” But they’re saying there’s no reason to have a bleed as if we’re talking about the same thing. They’re talking about how there was never a medical reason to install a fake bleed. And that is not the same thing as saying that there’s no medical reason to have an actual menstrual period. So I’m saying, hey, these two things are not the same. You could say there was never a medical reason for them to put an artificial bleed into the pill — they did that for marketing purposes. That is true. But you can’t then extrapolate that we don’t need to have an actual menstrual period from that. That’s just not true.
So this is certainly, hopefully, a little bit illuminating. It’s really fascinating to dig into the history of the birth control pill and the kind of psychology of it and to see how it has played out today. Now, today, after 60-plus years of this pill being on the market, women are used to it. It is normal to choose to suppress your period for many months at a time. And so that has opened up the door for drug companies to sell these pills that are 84 days, like the seasonal formulations, or to have methods where you just don’t bleed at all. And so I believe that these marketing companies are kind of taking advantage of our ignorance around the difference between a true menstrual bleed and an artificial withdrawal bleed.
Now I wanted to highlight this topic because these are some of the fascinating topics that I have covered in The Fifth Vital Sign in great depth. And if you haven’t had a chance to grab a copy, in celebration of the six-year anniversary, I thought I would share some of this on the podcast and invite some of our newer listeners to grab a copy and have a read through. We’ve had some incredible feedback, and it really goes into a lot of research that isn’t common knowledge.
I remember when I first started the podcast, I did it with this idea that fertility awareness had really changed my view of things. It changed my whole perspective on contraceptives. It helped me learn so much about my body. So I thought, if I start this podcast and share this information and share the fertility awareness knowledge because of my background as a fertility awareness educator, maybe other women will find it to be just as inspirational. And what I found is that over the years, we’ve had just an incredible amount of positive feedback. So many of you have reached out to share how this has impacted your life, how eye-opening it is, and how it has caused you to look at your own life and situation differently. And that’s how the book came about — to answer a lot of those questions. The primary question being: why aren’t we taught this stuff? Every woman should know this.
Hormonal contraceptives are so common and ubiquitous that many women who take them don’t even consider it to be a drug. And when they’re asked if they’re taking any medication in a questionnaire at a clinic, they won’t even list it, because it’s just the thing that you take all the time. Yet when you look at the warning labels for any of the common hormonal contraceptives, they all clearly state some of the most common side effects. And actually, a fun fact — when I wrote The Fifth Vital Sign, I have in chapter seven a kind of mock label, a drug label, which would be my interpretation of how I think it should be laid out. I feel like there should be a huge label that says “Warning,” and the side effects should be listed in layman’s terms. So that instead of “mood changes,” we could see things like depression, anxiety, low libido, panic attacks — so you can actually see the things that women are experiencing when they’re taking it. And I remember in that section I shared that there is a black box warning on hormonal contraceptives. The pill has a black box warning. And that warning is very specific to drugs that have a side effect of death — people who die using it. There’s a small percentage of women who have like a stroke, or pulmonary embolism, or some sort of blood clot event that results in their death. And there’s a study that they identified, showing that around 350 to 450 women are dying in the United States each year — the equivalent of a jumbo jet crashing every year — of women who are dying from using the birth control pill as directed. Even my editor, when she was going through that part, she had to go check because she didn’t know. And even she made that comment: “Wow, I didn’t know that there was actually a black box warning for contraceptives.” And this is the whole point.
So if you haven’t grabbed a copy of The Fifth Vital Sign, it’s available in paperback, ebook, and audiobook formats. You can grab the first chapter for free over at thefifthvitalsignbook.com.
So I wanted to share a couple of reviews in celebration of six years of The Fifth Vital Sign. The book has touched tens of thousands of women’s lives, and it’s just been an incredible way to open up this conversation about how important it is to look at the menstrual cycle differently — to say that the menstrual cycle isn’t only important when we’re trying to have children, but it’s actually important all the time.
Geralda wrote: “I have previously read Taking Charge of Your Fertility and Cycle Savvy before gifting them to young women to ensure they were age-appropriate, and loved both. I learned so much from those titles and am continuing my journey of education on the female body and fertility health. I just finished reading The Fifth Vital Sign and it is definitely a must-read. You did not get this education in school. Even doctors are not taught about any of this. It is a detriment to our health. This is vital information we should know. I spoke at length about what I was learning with my husband and we agreed that the information in this book is incredibly valuable to both women and men. My husband said to me that if he knew then what he knows now about women’s fertility health and hormonal contraceptives, he would never have wanted any of his girlfriends to take hormonal contraceptives. I am more confident in my overall health and well-being, including but not only about my fertility and my cycles. It is highly empowering as women to learn this information and understand how to use it to be fully informed about my overall health.”
Chelsea had to say: “Every single woman needs to read this book. This is everything we have never been taught, but the information we most desperately needed as teens when we were being pushed towards hormonal birth control instead by physicians and health ed teachers. It doesn’t matter how much you think you know about your body — you need this book. As a mother of girls, you need to be equipped with this info to pass along to your daughters, and when of age, they need to read it too. Buy this book. Gift this book to teen girls. Just do it.”
And Jennifer said: “A life-changing guide every woman needs. This book is a must-read for every woman. It offers invaluable insights into understanding your body and helps identify potential menstrual cycle issues that may need attention. Personally, it gave me a better understanding of my own health, especially after stopping birth control and uncovering underlying issues that had been masked. The Fifth Vital Sign empowered me with the knowledge to take charge of my health and answered questions even my OB-GYN couldn’t address. I’m incredibly grateful for Lisa’s work. It’s been truly life-changing.”
Now if you have been a longtime listener, fan, follower, and you haven’t yet had an opportunity to leave a review on Amazon for The Fifth Vital Sign and you have read the book, I would so, so, so appreciate it. Truly, when you leave reviews on Amazon, it’s one of the best things you can do to help us spread the word about the book. It shows potential readers what to expect, and it also helps to boost the rank of the book so that Amazon knows who to show it to.
I’m so thankful for all of you who have been part of the Fertility Friday community who’ve helped me to spread the word, who’ve shared about the book and the podcast. I believe that educating women at the grassroots level is truly where the change is going to come from. And as we continue to have more practitioners go through our FAM program, this is a way to exponentially increase the number of women who are learning about fertility awareness and being able to utilize the menstrual cycle as a vital sign in their own lives. So thank you so much for being part of the community and for joining in with me to celebrate the six-year anniversary of The Fifth Vital Sign.
If you can think of someone who would really benefit from listening to today’s episode, the share link is fertilityfriday.com/558. And of course, I hope that you have a wonderful week — or weekend — whenever you’re tuning into the show. And of course, as always, until next time, be well and happy charting.
Peer-Reviewed Research & Resources Mentioned
- Primary Dysmenorrhea: Advances in Pathogenesis and Management
- Menstrual Cycle Length In Reproductive Age Women Is An Indicator Of Oocyte Quality And A Candidate Marker Of Ovarian Reserve
- The Fifth Vital Sign (Free Chapter!)
- Real Food for Fertility (Free Chapter!)
- Fertility Awareness Mastery Mentorship (FAMM)
- How to Interpret Virtually Any Chart — For Practitioners! (Complimentary eBook)




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