A stock illustration of a Pink and blue ovary and fallopian tube

PCOS is dead. Long live PMOS.

Revealed Tuesday, the one-letter change in nomenclature for a common metabolic condition in women may seem unremarkable, but it follows more than a decade of vigorous debate over the need for a name that more precisely and completely describes what until now was known as polycystic ovary syndrome (PCOS).

The revised name — polyendocrine metabolic ovarian syndrome, or PMOS — was introduced in a paper published in The Lancet and presented at the European Congress of Endocrinology in Prague. It was the nearly unanimous choice of a panel of clinicians, researchers, and patient advocates, although there remains some dissatisfaction — in part because retaining “ovarian” in the name doesn’t allow for the possibility, suggested by some early research, of a male form of the syndrome.

As a name, PCOS had several limitations, including providing an inaccurate description of the condition, which does not manifest through cysts on the ovaries. This led patients to attribute ovarian cysts to PCOS and risk being underdiagnosed for other conditions, said Rachel Morman, chair of trustees at Verity, a U.K.-based charity and advocacy group for PCOS patients. Because doctors, too, would focus on the cystic presentation of the condition, patients could be dismissed if they didn’t present with cysts, even as they suffered from the metabolic and fertility issues linked with PCOS.

As a result, while the condition is believed to affect up to 13% of reproductive-age women — causing symptoms including weight gain, acne, hirsutism, irregular and painful periods, and mental health issues — the World Health Organization estimates that 70% of people with the condition are undiagnosed.

The journey to a new name started in October 2015, with a fight: At a meeting in Sicily, experts brought together to discuss renaming PCOS vehemently disagreed with one another. “That meeting was very colorful, I would say. There were lots of opinions in the room, no one was being heard, everyone was kind of talking over each other,” said Morman. “At the end of that meeting, it was like, we all agree it’s a bad name, but we can’t decide on what it should be.”

Over the next decade, the PCOS community underwent the most robust and extensive disease-renaming process in history. Building on earlier surveys administered in 2017 and 2023, a team led by Helena Teede at Monash University in Australia developed a third survey, which was administered to nearly 15,000 stakeholders in 2025. Overall, about 22,000 people across the globe — doctors, researchers, patients, charities — shared their thoughts on a new name.

Asked what they wanted a new name to accomplish, the primary response was avoiding stigma, followed by ease of communication and scientific accuracy; they preferred an accurate, descriptive name versus a generic one, and indicated a strong interest in including the involvement of the endocrine system in the condition.

Names were then tested in workshops with participants from all over the world, representing all interest groups.

The winning candidate, PMOS, was chosen in a landslide earlier this year over two other candidates: endocrine metabolic ovulatory syndrome and ovulatory metabolic endocrine syndrome. Out of 90 voters (including doctors, researchers, patients, advocates), 87 supported it immediately, and another came around by the time the manuscript was submitted. “I’m incredibly pumped about what’s to come as a result of this,” said Morman.

The only two dissenting voices were Angela Grassi, a registered dietitian and CEO of the PCOS Nutrition Center, and Sasha Ottey, executive director of PCOS Challenge, America’s leading PCOS association. Their concerns were primarily that the name changed too much without changing enough: It didn’t allow for the a potential male expression of the condition, which is being studied and was one of the factors leading to the renaming push, while it changed the acronym, requiring a significant marketing effort to disseminate the new name.

Teede, who is also the lead author of the paper, which she wrote with a group of international experts and patient advocates on behalf of the Global Name Change Consortium, said allowing for the possibility of a male version of the condition, hence doing away entirely with reference to ovaries, was one of the key matters of debate.

But from a patient advocacy perspective, Morman said, considering men in changing the name would have been a mistake because it might have delayed a decision until more research was completed, and shifted the focus away from women. “I fundamentally do not agree that waiting for a name change and then potentially changing it to encapsulate men is a wise thing to do. In fact, I would think that that would be even more harmful than keeping the name PCOS,” she said, adding that expanding the condition’s name to men would have diluted the resources dedicated to women, who are already shortchanged when it comes to medical research efforts and funding.

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Ultimately, after multiple rounds of voting, the consortium decided to maintain a reference to the female reproductive system, though without using “ovary” and “ovulatory,” because they felt too limited. “Ovarian encompasses a lot more,” said Teede, including “the hormonal changes in the ovary and the follicle responses in the ovary.”

She said the other alternative would have been something that used “reproductive” instead of “ovarian” but “to create a name with reproductive in the title was felt, especially in many cultures and world regions, to be too stigmatizing and likely to cause harm,” she said.

In the end, she said “the most accurate naming in fact may have actually been slightly different to what we ended up with, but we had to consider the perspectives of everybody, and the cultures and the environments and implications that they have.”

The expectation shared in the paper is that it will take about three years for the promotion and dissemination of the name, but Grassi is skeptical the effort will be sufficient, and worries about the costs incurred by companies and organizations like hers, which revolve around the condition and are named after the now-obsolete acronym. “I feel that changing the acronym is a mistake. It’s going to cause a lot of confusion. This is money that’s going to have to be spent on rebranding — I have to rebrand, I have to buy new trademarks, I have to buy domains; my book, ‘The PCOS Workbook,’ needs to be redone.”

But maintaining PCOS was never much of a possibility. Only a quarter of survey responders said they would like to prioritize maintaining the acronym in the new name, and over half outright rejected maintaining the acronym unchanged. “They did so on the basis that they felt that change was critical, and if none of those letters changed, then they didn’t think it was enough of a change,” said Teede. While she sees the point Grassi made, she also thinks individual business interests are secondary to a patient perspective in the process.

“All this work to change a C to an M,” said Grassi, adding that she is convinced further research will likely find more about a male version, and require further change. But Teede is not worried this will be the case: “This was intended to be a very definitive process,” she said, but “unless something dramatic changes in the science of this condition in the future, then we would not anticipate that it would change again.”

STAT’s coverage of health challenges facing men and boys is supported by Rise Together, a donor advised fund sponsored and administered by National Philanthropic Trust and established by Richard Reeves, founding president of the American Institute for Boys and Men; and by the Boston Foundation. Our financial supporters are not involved in any decisions about our journalism.

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PCOS’s new name is PMOS, a small letter change that required a big scientific process