Polycystic ovary syndrome has been given a new name: polyendocrine metabolic ovarian syndrome, or PMOS, after a vote that was nearly unanimous and a process that stretched across a decade. The revised terminology was introduced in a paper published in The Lancet and presented at the European Congress of Endocrinology in Prague on Tuesday.

The change matters because the old name had long been criticized as misleading. PCOS does not manifest through cysts on the ovaries, even though the condition is believed to affect up to 13% of reproductive-age women and the World Health Organization estimates that 70% of people with the condition are undiagnosed. For many patients, the label has been more than a semantic problem: doctors may focus on ovarian cysts that are not actually there and miss the metabolic and fertility issues that do define the disorder.

The new name was the nearly unanimous choice of a panel of clinicians, researchers and patient advocates, and it capped a process that began in October 2015, when experts met in Sicily and could not agree on a replacement. Rachel Morman, reflecting on that meeting, said it was “very colorful,” with lots of opinions in the room, nobody being heard and everyone talking over each other. She said that by the end of the discussion, the group agreed the existing name was bad, but could not settle on what it should become.

That disagreement set off a long search for a better term. Earlier surveys were conducted in 2017 and 2023, and a third was administered in 2025 to nearly 15,000 stakeholders. In all, about 22,000 people around the world weighed in on the naming question, making the effort the most robust and extensive disease-renaming process in history, according to the background provided with the announcement.

PMOS emerged as the winner earlier this year in a landslide over two other candidates, endocrine metabolic ovulatory syndrome and ovulatory metabolic endocrine syndrome. Out of 90 voters, 87 supported PMOS immediately, leaving the other two options well behind.

The decision does not change the condition itself, but it does change the language around it, and that is the point. A name that once pointed patients and doctors toward cysts — and sometimes away from the real disorder — is being replaced with one meant to better reflect the endocrine and metabolic features at the center of the illness. For the millions of people affected, the next step is straightforward: medical systems will have to decide how quickly they adopt PMOS, and whether a new label can help patients be recognized sooner.