So-called feminine hygiene products are self-effacing by design. Imperceptibility—the “no feel protection” advertised by Always pads, the “made to go unnoticed” tagline of Tampax—is the gold standard, or at least the chimerical promise, of the various absorbent or fluid-capturing products put in or near vaginas on days when effluent from the uterus is expected. Devices that aspire to nonexistence can still, however, be big business. As the Norwegian historian Camilla Mørk Røstvik notes in Cash Flow, the “menstrual economy” is booming, expected to reach $27.7 billion by 2025.

Cash Flow describes the rise of this industry through a series of case studies from 1945 to the present, showing how the development and marketing of various menstrual products has at times catalyzed, at other times mirrored, seismic economic and cultural shifts around the world. The widespread buying and selling of pads, tampons, and other devices became possible only quite recently, once enough people were willing to accept that menstrual “blood” (in fact about one-third blood and two-thirds other substances), “a free and renewable material,” merited its own “consumer event.” Over the past century semen, blood, and breast milk have run along parallel channels, becoming or generating a cascade of commodities—some genuinely life-changing, others more dubious.

In the case of tampons and pads, part of the sleight of hand that keeps profits flowing so menorrhagically is the illusion that consumers are participating in a taboo-breaking revolution—finally “free to be free,” as an old Tampax ad campaign had it—when in practice they are merely free to choose from among the wares of a small handful of multinational corporations. These products have also become more expensive relative to other goods, as outsize advertising costs, passed along to consumers, stifle the growth of most smaller firms. As far back as 1978, the UK House of Commons investigated potential price-fixing within the industry. Failing to find explicit collusion, the commission nonetheless pleaded, rather toothlessly, that “advertising costs and such promotional costs as do not represent direct benefits to the consumer should be reduced and the savings passed to the consumer.” More recently, the catastrophic effects of climate change on crops such as cotton have caused yet further price hikes; in 2022, after Texas farmers abandoned 74 percent of their cotton crop, tampon prices rose 13 percent. (The price of cloth diapers went up 21 percent.)

None of this is very different from the recent history of gas stations, burger and coffee chains, social media platforms, or other enterprises that rely on the message that transacting with an oligopoly still constitutes some kind of “freedom”—except for the fact that menstrual products are closer than most others to a necessity, perhaps even a right. As a recent law review article puts it, few in the US carry around their own roll of toilet paper for use in bathrooms outside the home, yet menstruators live under an implicit “Bring Your Own Tampon” policy—one that, the author argues, constitutes “a violation of human rights and equal protection.”* Menstrual products, the article contends, should be freely available in the bathrooms of private businesses and public spaces. (It’s far from clear whether such a scheme would drive down the price of these products; one can easily imagine a scenario of lobbied-for mega-contracts in which the opposite occurs.) At the very least, many argue, tampons and pads ought not to be taxed (as they are in twenty-one US states) when groceries and other necessities are usually not.

On the other hand, some environmentalists and public health experts question how essential menstrual products are, arguing that we ought not to accept at face value the notion that there’s no alternative to these landfill-stuffing bundles of cotton, rayon, and plastic. People have used more renewable and less extractive technologies before; they might well again. (Things like silicone menstrual cups and reusable “period underwear,” for example, are indeed on the market now, and public health studies show that reusable products are generally viewed favorably by participants given free access to them, though the general public remains slow to adopt them.)

Yet “period poverty”—inadequate access to hygiene products, the means of washing and waste disposal, and basic gynecologic health education—is demonstrably real. As the anthropologist Kate Clancy reports in Period: The Real Story of Menstruation, it regularly takes a fair number of children out of school and adults out of work and, for those suffering from severe poverty, even shifts some of those children and adults toward transactional sex, whether for money or for bartered access to basic health and hygiene needs.

Clancy sympathizes with the “worthy goal” of aid and development projects—often based in poor countries—to increase access to menstrual products and ways to safely change, wash, or create them. But she points out that “turn[ing] to periods as a site of intervention” ignores how period poverty is almost always accompanied by plain old poverty. When a study shows that period poverty is predictive of low educational and financial attainment, it does not follow that giving someone a pad will mitigate these circumstances. Evidence suggests that such interventions do not have much impact on school attendance or dropout risk.


Likewise, people experiencing period poverty acquire more infectious diseases, though probably because being poor makes good health and hygiene elusive in general (and can push people toward higher-risk practices like sex work) and not because, say, homemade cloths or traditional techniques for dealing with menstruation are necessarily dirtier or less effective than what researchers or aid workers bring to targeted communities. “Periods themselves are not necessarily the culprit, or at least they wouldn’t be under different conditions,” writes Clancy.

Outside the realm of research and aid, the marketplace can also fail the needs of women and girls in the Global South. To take one of Røstvik’s examples: after years of side effects—rashes, itching, and other untoward symptoms—reported by Kenyan consumers of Always pads, a media investigation found that Always products sold in Africa used a different, older formulation of plastic than those sold in the West. Procter and Gamble, owner of Always, released a video called #GenerationOfChange that told viewers: “You spoke, we listened, we improved”—a nonapology that came more than twenty years after women began to complain.

Does the way we think about the needs and rights of menstruating people change if, as the physician and CEO Sophia Yen puts it, we “make periods optional”? Yen runs a direct-to-consumer company that sells various forms of birth control, but central to the pitch is the idea that hormonal contraceptive pills and vaginal rings are perfectly safe to use continuously, without the week of sugar pills or week of ring removal that’s become customary to provoke a withdrawal bleed. This is supported by a wealth of evidence: as the UK’s Royal College of Obstetricians and Gynaecologists puts it, “There is no health benefit from the seven-day hormone-free interval.” Some scholars have argued that the “bleed” (again, not exactly blood, but a host of organic materials) at the end of each pill pack was designed both to win over consumers and to win approval from institutions like the Vatican by giving users a “pill period” (not actually a period at all) so that their cycles would resemble those of any other “normal” woman.

But Yen goes further, arguing not just the amply substantiated fact that for most patients continuous hormonal contraception is as safe as intermittent use, but that people who menstruate would do well to drastically reduce their number of lifetime periods. Her reasoning is both social and biological. As she tells Leah Hazard, a midwife and the author of Womb: The Inside Story of Where We All Began, Yen remembers getting her period in the middle of a high-stakes exam at MIT. Torn between getting up to use the bathroom and pressing on, she looked around and realized of her male classmates that “never in their life have they been hit by random blood in the middle of an exam. And now, looking back, fifty percent of that class had a uterus, and one in four was bleeding at that moment.” Young women and others who menstruate, in other words, face genuine obstacles to success because of their periods, particularly (though Yen doesn’t spell this out) when it comes to the hypercompetitive entryways into elite educational and job opportunities. The pharmacological elimination of periods for long swaths of one’s adolescence and adulthood could, the argument goes, enhance girls’ and women’s performance by eliminating the pain and other symptoms of menstruation and the material nuisance of a bodily fluid, as well as the debatable cognitive effects of blood loss and hormonal oscillation.

It is true that, as Yen states, for much of human history women averaged fewer total periods than most (at least in the West) do today. Frequent pregnancies, often followed by months to years of breastfeeding, as well as missed cycles in times of decreased food consumption or increased exertion, added up to years without menstruation. Yen estimates that whereas the average contemporary woman has 350 to 400 lifetime periods, the “natural” and ideal number would be about a hundred.

Whether an older way of inhabiting one’s body is necessarily better remains an open question, however. The privileges of modernity—unevenly distributed, to be sure—such as access to family planning, expanded options for safely nourishing babies and toddlers, and increased food supply, all create conditions in which women menstruate more. And dying young, of course, is another surefire way to avoid racking up an excessive number of lifetime menses. Young women in Tudor England who survived to adolescence had a life expectancy of less than fifty years. Even today, in low-income countries one in forty-one women dies from complications of pregnancy or childbirth. A woman who accrues four hundred periods is likely someone who has not been subject to starvation, has not carried numerous unwanted pregnancies, and has been able to see a doctor when she’s sick.


Using hormonal contraception to limit the number of lifetime menses does pose other risks: most forms of the Pill slightly increase the risk of breast and cervical cancers while slightly lowering the risk of ovarian, endometrial, and colon cancers, according to most observational studies. Because these studies don’t, for obvious reasons, randomize so that participants take either real contraception or a placebo, there may be other differences between people who choose the Pill and people who don’t that partially account for these findings. But it is not far-fetched to imagine that the steady exposure to small quantities of synthetic hormones, in contrast to the complex oscillations of the body’s own endogenous reproductive hormones, would affect our cellular function in fundamental ways.

Broadly speaking, in many societies a menstrual stigma exists such that “the good period” is, in the feminist scholar Chris Bobel’s words, “the one we don’t know about.” “Technologies of passing” is the term coined by the historian Sharra Vostral for all the drugs and products that allow someone to conceal their menstruation or avoid menstruating altogether. A well-functioning tampon allows for leak-free swimming and white jeans. A period-tracking app, or a birth control method with a scheduled week of removal or placebo, offers users the ability to predict (and prepare to conceal) their flow. In Period Clancy argues that such technologies are too often presented as a gift or advantage to women and girls—Isn’t it wonderful that X helps you hide/manage your period so well?—when in reality “the hyperawareness with which we have been taught to monitor change in our menstrual cycles” and “hyperawareness of menstrual cleanliness” are both “method[s] of control, rather than being tied in an appreciable way to our health or well-being.”

In a hypothetical society not at all grossed out by periods, someone signaling that they needed a few minutes to take care of a bodily function—or visibly carrying a menstrual product—would not be so alarming. It was only some half-dozen years ago that Essity began using red liquid in television advertisements to represent (still fairly abstractly) how their Bodyform pad was able to absorb blood; for much of the twentieth century, bright blue liquid was usually used instead.

What we prefer not to know extends beyond menstruation itself to its management and the management of women’s health more broadly. One study estimates that in the UK alone, more than three billion single-use menstrual products are used and discarded annually, creating nearly thirty tons of waste each year. The hormonal birth control ingredient ethinyl estradiol—a substance I myself ingested and excreted for some twenty years, and likely will again as soon as I stop breastfeeding—is detectable in groundwater, persists there longer than estrogen made by the body, and is known to harm marine life and possibly other creatures. Many of the hormone replacement therapies used to relieve the symptoms of menstruation’s slow diminuendo and cessation—menopause—are extracted from the urine of pregnant horses, fueling an enormous supply chain of factory-farmed mares and by-product foals that are mostly slaughtered. Whether one is regulating, concealing, or trying to manage the loss of one’s period, one is very likely doing the planet and its flora and fauna no good.

Another challenge for people menstruating is the difference between the body’s rhythms—orchestrated by a complex combination of genetics, endocrine feedback loops, environmental causes, and more—and the temporal structure of contemporary life. In an age of calendars, alarm clocks, and schedules that standardize the way we experience time—and modern practices that work to obfuscate things like seasonal shifts in food supply or hours of daylight—the variance in the rhythms of unmedicated periods remains something of a stubborn throwback. In fact, differences in menstrual cycles, among women and within the same woman, are much more pronounced than is commonly taught in health classes or doctors’ offices.

The cycle most people are taught goes as follows: during the first fourteen days of a twenty-eight-day cycle, called the follicular phase, ovarian follicles are stimulated into development by a variety of hormonal triggers. Ultimately one dominant follicle releases an oocyte, or immature egg cell. The second half of the cycle is known as the luteal phase. Here the remaining follicle, now called a corpus luteum (“yellow body,” for the visual appearance of the fatty compounds within it), releases a rising tide of progesterone and estrogen, causing the uterine lining to thicken. After another two weeks, if no fertilization has occurred, the corpus luteum degenerates and stops producing hormones, becoming a corpus albicans (a “body turning white”). The sudden drop in progesterone and estrogen causes the uterine lining to slough off, and menstruation follows. If the oocyte was fertilized by a sperm cell, begins dividing, and manages to implant as an embryo in the lining of the uterus, the outer cells of this structure—the future placenta—send a hormonal signal to the corpus luteum to keep it pumping out progesterone and estrogen for the first months of pregnancy. No hormonal dip, no shed lining, no period.

There are, however, significant cycle differences within the same person, with patterns dynamically impacted by environmental, immunologic, and social stressors. And while self-harming behaviors like intense caloric restriction can cause drops in estrogen, with a variety of consequences, including the absence of periods, Clancy urges us not to think in terms of aberrancy when the body’s interplay of signals holds ovulation, fertilization, implantation, or other events at bay. Idealizing normal menstruation—which takes up a great deal of energy and nutrients—as what the body “ought” to do misses how fortunate it is that female physiological mechanisms of self-defense attempt to limit reproduction only to instances “when you possess enough resource to handle its costs—not merely the energy needed for a menstrual cycle but the energy needed for years and years of pregnancy, lactation, and parenting dependent offspring.”

Menstrual cycles in which parts of the process are skipped or terminated are not, physiologically speaking, a waste of energy either: evidence suggests that nonprocreative cycles might gradually promote alterations to the uterine lining that make successful embryo implantation more likely. And in the meantime, “your body is prioritizing your survival over your reproduction, as it should.” Would that the outside world shared those priorities.

Finally, a common source of suffering deeply entwined with the menstrual cycle is hormonally driven chronic disease. To name one example, leiomyomas (more commonly known as fibroids) are benign tumors on the walls of the uterus. While an estimated 70 to 80 percent of women will likely have a fibroid at some point in their lives, ranging from pea-size to grapefruit-size and larger, only a small fraction will suffer from fibroid disease, in which the growths can cause chronic pain, heavy periods, bleeding between menses, painful sex, and dysfunction of the bowels and bladder, with serious impacts on a person’s mental health and daily functioning. Estrogen fuels the growth of fibroids, so its recurrent waves during menstrual cycles can worsen symptoms. Low-estrogen or no-estrogen hormonal contraceptives, as well as the onset of menopause, can lessen symptoms, though some people will need surgical removal of the fibroid or, as a last resort, the entire uterus.

In endometriosis, another prevalent condition that for some becomes a life-altering chronic disease, tissue mimicking the lining of the uterus (the endometrium) grows elsewhere in the body (most commonly in the pelvis). Studies demonstrate that the development of endometriosis is at least partially prompted by inflammation, though the growths themselves then prompt further inflammation and scarring, leading to chronic pain, long and heavy periods, and difficulty getting pregnant. The condition, which affects perhaps 10 percent of women and girls, is definitively diagnosed by examining surgically obtained tissue (usually through laparoscopy), though MRI (and, to a lesser extent, ultrasound) can also correctly diagnose endometriosis in many cases, and often a patient’s history and exam are clear enough to allow for a presumed diagnosis.

As with fibroids, hormonal treatments and surgical options can help, though scarring and changes in the nervous system’s threshold for perceiving pain (eventually creating the experience of pain even in the absence of a stimulus) can create long-term debilities. The late Hilary Mantel, who wrote unsparingly about her own endometriosis, describes how she languished for years without a diagnosis—“a skinny, grey-faced scrap, bleeding continuously and hardly able to stand upright”—and how even after surgery she continued “to live in a body I didn’t recognize.” The so-called benignity of these conditions—in the sense of their being noncancerous—belies the shadows they cast across millions of lives, often most ferociously during one’s period.

Whether a person has “normal” periods, healthy periods that don’t resemble the textbook, or any of the mild to severe illnesses fueled by the menstrual cycle’s hormonal ebb and flow, what that person will need and want from clinicians, the marketplace, their workplace, and their community is hardly consistent. Nor can it be deduced from the “view from nowhere,” Thomas Nagel’s term (quoted by Clancy) for philosophical standpoints that claim objective universality but often have embedded assumptions marked by the claimant’s gender, race, health, or other factors. Take the somewhat dramatic example of hysterectomy as an option for relieving disorders and diseases related to menstruation: the fact that Black women in the US undergo this surgery at significantly higher rates than white women raises concerns—amplified by the odious history of eugenics and reproductive control in the US and elsewhere—that Black women are less likely to be offered treatment alternatives. At the same time, many people are appalled by the ordeals and delays they face when trying to advocate for their own hysterectomy (and might object to my use of the word “dramatic” above, since it might be tinged by a bias toward keeping the organs one was born with). Is the problem too many hysterectomies or not enough? An ongoing blight of notorious “Mississippi appendectomies,” or insufficient access to care? Both, of course.

The explicitly feminist outlook of recent books on menstruation and the organs involved helps make sense of these kinds of superficial contradictions. In Cash Flow, Røstvik begins by mentioning her “feminist archival method in which the voices of women and minorities are prioritised.” Thus we hear not just from captains of industry but from the minutes of workers’ committee meetings at a Norwegian menstrual pad factory that hired mostly housewives seeking extra income. And Røstvik is careful to measure the differences between appearances (“They are really so cute in their new uniforms,” says a 1978 article from the in-house magazine of the Norwegian company, written by male employees, about its female factory workers) and the reality of the workplace, where shoddy heating and cooling, low light, and horrendous noise and air pollution tended to prevail.

Clancy, who runs a “feminist science lab that studies the environmental stressors that can affect the menstrual cycle,” champions studies that question the assumptions that can lead to persistent bias in research. For example, many studies about the health impacts of physical activity involve the aerobic activities that come to mind for most Americans when we hear the word “exercise”—walking, running, swimming, or other steady, continuous activities set apart from the rest of life’s routines. Clancy discusses studies that seek to capture the light, intermittent, but cumulatively remarkable amount of exercise done by rural women performing housework and other forms of manual labor, finding associations between this kind of work and improved bone density, decreased risks of fractures and breast cancer, and intriguing alterations to the menstrual cycle. She makes no claim that anyone “ought” to do manual labor of any kind—simply that the health impacts of many kinds of work and movement tend to go underdescribed in medical and academic circles, to the intellectual impoverishment of us all. We cannot begin to understand what we have not even noticed or articulated.

In Womb, Hazard cautions that the prizing of convenience and performance enhancement (prioritizing, for example, workplace or classroom productivity over a gentler accommodation of the body’s menstrual needs) has warped women’s body image and tends to foreground adaptations to a broken world (medical elimination of one’s period, for example) rather than challenges to the structures and assumptions underpinning the status quo. She wrestles with whether not offering her daughters a period-free life through continuous hormonal contraception deprives them of an “academic edge” and a pharmacological tool “to level off [her] moods.”

One way an intervention gains ethical and practical legitimacy in Hazard’s view is by helping a person feel “maximally at home in one’s body.” Pushing one’s daughter to take the Pill for the sake of her GPA or college applications (fewer bathroom trips during final exams!) might be morally dubious, but permitting or encouraging hormonal contraceptives insofar as they promote her happiness and bodily comfort seems to Hazard like a more straightforward act of empathy. She extends this to other categories of vulnerable people whose menstruation management might be decided or influenced by their caregivers. Medically or surgically blocking the periods of people with disabilities just because caregivers don’t like the cleanup, or are made uncomfortable by reminders of their charges’ sexual organs, is unacceptable to Hazard (and to many scholars of disability ethics) because it doesn’t concentrate on the actual wishes and experiences of the vulnerable. Ease is in the eye of the beholder, and many people (though certainly not all) feel most at home in their bodies when their organs can chug along unimpeded by all the idiosyncratic and inconvenient rhythms of their cyclical activities.

Even for those of us relatively in charge of our own lives, Hazard worries whether some technologies are teaching us to hold our bodily functions too much at arm’s length. Take period-tracking apps, for example: while they are convenient for predicting bleeding and other symptoms, optimizing or avoiding conception, and more, Hazard agrees with the economist Alnoor Bhimani that “the apps’ main appeal lies in their ability to sanitize an otherwise conceptually ‘dirty’ process.” When health information is digitized, the interface spits back an image of ourselves in glowing color and sleek graphic design, flattening and flattering at once. Users enjoy the feeling of control over their bodily functions while perhaps underestimating or ignoring their relative powerlessness regarding how their data will be tracked and monetized.

Hazard hopes that deep attention to and curiosity about the female body might counteract a strain of contemporary thought that sees female biological processes as problems to be solved, eliminated, or managed. In her work as a midwife, she attends to the particularities of what the female body and its organs are actually like as phenomena, taking us into the clinic as she examines a pregnant patient:

Now, then, you are close enough to smell her breath: mints, or masala, or the pear-drop fug of ketones. Your legs press against the side of the bed as you ask if you can touch her…and finally, the pads of your fingertips rest against her abdomen…feeling for the tone and shape of the uterus, and the parts of the passenger within it…. Your hand glides down and there it is, the size and shape of the sleek, round head of a cat, nestled pleasingly under the curve of your palm.

Periods, and the organs that create them, are more sophisticated and more unruly than most of us have been taught.