The name change

Why PMOS and not PCOS?

In May 2026, after fourteen years of work, polycystic ovary syndrome got a new name. Here's who decided, why, and what it means for you.

Written by the Lila team · Sources linked below · 3 min read · Updated

If you were diagnosed with PCOS, you may have noticed the name shifting around you. That's not a mistake or a marketing choice. In May 2026, an international consensus published in The Lancet formally renamed the condition polyendocrine metabolic ovarian syndrome, or PMOS.

What was wrong with the old name

Two things, and both mattered.

The first is that it was inaccurate. "Polycystic" points at cysts on the ovaries, but research published alongside the name change confirmed there's no increase in abnormal ovarian cysts in this condition. What shows up on an ultrasound are follicles, a normal part of ovarian anatomy, present in greater numbers. Generations of people were handed a diagnosis named after something they didn't have.

The second is what the name hid. By putting the ovaries at the centre, it buried everything else: the insulin resistance, the raised risk of type 2 diabetes and cardiovascular disease, the effects on skin, weight, and mental health. Clinicians and patients alike have argued for years that this framing contributed to missed diagnoses, fragmented care, and a condition being treated as a fertility footnote rather than the lifelong metabolic disorder it is.

A name isn't cosmetic. It decides which specialist you're sent to, which risks get screened for, and whether anyone takes you seriously.

Where the new name comes from

Each word does work the old name didn't:

  • Polyendocrine: multiple hormone systems are involved, not just reproductive ones
  • Metabolic: insulin resistance and long-term metabolic risk are central, not incidental
  • Ovarian: retained, because the ovaries are genuinely part of the picture

The process was led by Professor Helena Teede at Monash University with the Androgen Excess and PCOS Society and the UK charity Verity, drawing in 56 organisations and more than 22,000 survey responses. It was the largest initiative ever undertaken to rename a medical condition.

It wasn't unanimous. Some advocates argued it didn't go far enough. Keeping "ovarian" leaves no room for a possible male form of the syndrome that early research has hinted at.

What this means for you

Your diagnosis hasn't changed. The criteria are the same, your treatment is the same, and you don't need to be re-assessed. A three-year transition is underway, with full adoption expected in the 2028 international guideline update, so you'll see both names in circulation for a while yet, and your own doctor may still say PCOS.

We use PMOS at Lila because it describes the condition honestly. We'll keep saying "formerly PCOS" for as long as that's the phrase people are searching for.

Lila is a companion and a record, not a doctor. This article is general information, not advice about your situation.

Quick answers

Why was PCOS renamed PMOS?

For two reasons. The word polycystic was inaccurate, because the condition does not involve an increase in abnormal ovarian cysts; what appears on ultrasound are follicles, a normal part of ovarian anatomy. And the old name put the ovaries at the centre and hid the insulin resistance and long-term metabolic risk that sit at the heart of the condition.

Who renamed PCOS, and when?

The new name was published in The Lancet in May 2026 after an international consensus process led by Professor Helena Teede at Monash University, with the Androgen Excess and PCOS Society and the charity Verity. It involved 56 organisations and more than 22,000 survey responses.

Does my PCOS diagnosis change now that it is PMOS?

No. The criteria and treatment are the same, and you do not need to be re-assessed. A three-year transition is underway, with full adoption expected in the 2028 international guideline update, so you will see both names for a while.

Why does Lila say PMOS (formerly PCOS)?

Lila uses PMOS because it describes the condition honestly, and keeps saying formerly PCOS for as long as that is the phrase people search for.

Sources