Back in 2017, Martis wrote an article for The Walrus, advocating for paid menstrual leave in Canada, so that those who suffer from debilitating period pain could take time off. And while Canada has yet to enact the policy, some other nations and cities around the world are embracing—or at least pondering—it. Indeed, earlier this month, Girona became “the first city in Spain to consider a menstrual leave policy,” according to Time. Meanwhile, such policies have been in place for years in some parts of Asia and elsewhere, earning both fans like Martis and detractors who say period leave is unnecessary or enforces antiquated stereotypes about women.

In the U.S., President Biden’s massive spending plan initially included a paid family leave proposal, which would have brought the country closer in line with the rest of the world (the U.S. is currently the only wealthy nation that doesn’t offer some kind of paid family leave). It was a moment that also excited advocates of other types of paid leave—including period leave—but that elation was short-lived: Biden’s paid family leave policy was stripped out of the bill this week.

Could the U.S. ever get its own paid period leave? As Washington just made clear, the answer at the federal level seems to be a clear no, but that doesn’t mean it might not become an enticing option for some U.S. employers— especially at a moment when many are looking for new perks to help them stand out in a hot labor market.

The history of paid period leave

While paid menstrual leave has yet to take root in North America, it’s found a foothold elsewhere in the world. In the 1920s, period leave fluctuated in and out of public favor in Soviet Russia, before dissipating for good in the 1930s. In 1947, Japan initiated a period leave policy for “female factory workers” with painful periods in poor working conditions. Since 1953, South Korea has allowed one day off per month. Taiwan’s national policy started in 2002, Indonesia has provided up to two days off for period pain since 2003, and Zambia’s period leave policy is known as “Mother’s Day.” Certain provinces in both China and India offer time off as well; in 2016, China no longer required employees to provide a doctor’s note to prove period pain.

Yet even when such policies are adopted, it’s not clear how effective they are. In countries like Japan and Korea, reports find that the number of people taking the leave has fallen over time. The BBC reports that the former CEO of Asiana Airlines denied 138 requests for period leave between 2014 and 2015. Last March, the Jakarta Post wrote that an Indonesian reporter did not even know she could take time off, and was denied it when she finally asked.

Who wants paid period leave?

Not all paid menstrual leave is government mandated. In some cases employers have made their own decisions to adopt the policy. Just over a year ago, Zomato, a multinational food delivery company headquartered in northern India, introduced period leave for its menstruating employees. Founder and CEO Deepinder Goyal wrote in a blog post: “Starting today, all women (including transgender people) at Zomato can avail up to 10 days of period leave in a year.” Since then, 621 employees have applied for a leave, a Zomato spokesperson told Fortune, adding that its policy “has helped enable a culture of trust, truth, and acceptance.”

In 2016, Bex Baxter, development director of Coexist, a social enterprise in Bristol, U.K., partnered with Dr. Lara Owen, a consultant and researcher of menstruation and menopause based at the University of St. Andrews, to craft the company’s new period leave policy. Owen reports that the team started with the a conservative version of the plan, which offered time off in consultation with the manager that would eventually be “paid back” in hours later on. During the trial period, it became clear that paying back time caused employees additional stress, so the company dropped that portion of the policy, instead simply paying menstruating workers for the time off. The result? According to Owen, even non-menstruating employees became more comfortable voicing their needs.

What’s the argument against it?

According to Sally King, founder and research director of the online resource hub Menstrual Matters, the history of period leave has something of an insidious undercurrent. Some countries’ menstrual leave policies are rooted in antiquated ideas, she says, including the belief that periods are shameful and so should be kept private or that working during a painful period could negatively impact fertility. Naming a day off as “period leave,” King says, leads to additional discrimination by reinforcing “myths and [incorrect] assumptions about the female body.” She says such policies can also hurt women’s upward mobility in the workplace or prevent an employer from hiring them altogether.

King worries sending people home on their period both normalizes period pain (when it could actually be a sign of a serious health issue) and the idea that you have to suffer privately. The lack of conversation is precisely what keeps menstruators in pain, she says.

Public opinion of menstrual leave varies, according to a 2019 U.S. study. Nearly half of the 600 participants said they’d expect a menstrual leave policy would have both positive and negative effects. Sixteen percent worried the policy would make menstruators look weak and put them in danger of discrimination. Another 11% of the study’s participants said such leave isn’t necessary, and 13% said a sick day would do. One participant wrote: “Our menstrual cycle is a natural thing that we should get used to.” 

Dr. Fareeda Haamid, an assistant professor of clinical pediatrics and a clinician with Nationwide’s Young Women’s Hematology Clinic, admits she’s torn on the issue of period leave because she sees the good intentions, but also worries the policy could label the menstrual cycle as a problem. One thing she’s sure of: “This notion that not enough people suffer [from periods to justify a leave] is nonsense.” 

Dysmenorrhea is the blanket term used to describe menstrual pain. When Haamid spoke with Fortune, she said she’d seen three patients come into her office with debilitating cramps in under a week. According to a global 2019 study led by Mike Armour, which encompassed a total of 38 studies including 21,573 young women from all over the world and a variety of socioeconomic backgrounds, 71% of participants reported experiencing dysmenorrhea “irrespective of the economic status of [their] country.” Just over 20% reported having made the decision to leave school owing to cramps, while nearly 41% said their pain negatively impacted their studies.

Martis, the Canadian journalist, was clinically diagnosed with endometriosis based on her severe symptoms. She’s still waiting for an official diagnosis, which, in the case of endometriosis, can take an average of 7.5 years. A fundamental problem in menstrual health, Martis says, is how unlikely doctors are to believe women’s pain, especially black women and women of color. 

Is the U.S. ready for period leave?

The United States does not currently have federally mandated paid time off. The issue has been front and center lately, as President Biden initially included a paid family leave provision in his American Families Plan. But that proposal has now been cut out of the bill in attempt to appease Democratic West Virginia Sen. Joe Manchin, who has balked over the cost.

Given the difficulty of passing paid family leave—a policy that’s widely supported by the American public—Amber Clayton, who leads the Knowledge Center at the Society for Human Resource Management, doubts paid period leave will be coming to the U.S. on a nationwide level anytime soon. She does, however, see an opportunity for companies to consider the issue.

“When it comes to being competitive in the market for talent,” Clayton says, “this could be something that could help an employer stand out.” She can see a future where period leave exists, but there would be a lot of serious questions that interested employers would have to address, she says, including who would be eligible and what type of documentation would be required to qualify.

One model might be found to the north: On Oct. 12, Canadian menstrual device maker Diva International adopted a policy that provides menstruating employees with one paid day off per month. In the company’s public announcement, president Rick Saini said of the policy: “We at Diva strongly believe that employees should not be put in the position of ‘presenteeism’ and feel pressured to show up to work even when feeling sick, or when it is a detriment to their health.” The policy can be used at employee’s discretion and does not require a doctor’s note, wrote CEO and founder Carinne Chambers-Saini, because “we believe women and want to empower them in managing their care.”

At a moment when many companies are rethinking how they address worker health, both physical and mental, even menstrual leave opponents like King will allow that such policies could expand the discussion about what wellness should mean in the modern workplace. But Owen says it’s even deeper than that: “[Menstruators] have [their] own inner critic that tells us we really shouldn’t be taking time off; we should just be able to grin and bear it…That’s why I think the policies are important, because that legitimizes looking after yourself.”

Clarification, Nov. 8, 2021: An earlier version of this story mischaracterized dysmenorrhea. The term refers to any type of menstrual pain. It also misstated the details of the paid leave policy adopted by Coexist. The company provided paid leave to menstruating employees.