PMOS (formerly PCOS): What Changed and What Did Not

PMOS: the new name for PCOS

In May 2026, polycystic ovary syndrome (PCOS) was formally renamed polyendocrine metabolic ovarian syndrome (PMOS) following a global consensus process, published in The Lancet.

If you have PCOS, the most important thing to know is this: nothing about the condition, its diagnosis, or its treatment has changed. Only the name.

Why it was renamed

The old name was inaccurate in two specific ways, and the inaccuracy had consequences.

"Polycystic" implies cysts that are not there. What is seen on an ultrasound in PCOS is not cysts. It is a larger-than-usual number of small follicles — eggs that started developing and stopped. Calling them cysts has frightened a great many women unnecessarily, and led some to expect surgery that was never indicated.

"Ovary syndrome" is too narrow. The condition affects multiple hormone and metabolic systems, not just the ovaries. Insulin resistance with compensatory high insulin is present in 85% of those affected. Framing it as an ovarian problem has contributed to the metabolic side being overlooked — which matters, because that is what affects long-term health most.

The new name reflects three interacting disturbances: polyendocrine (multiple hormone systems), metabolic (insulin resistance), and ovarian.

The scale of the consultation

This was not a small committee decision. The renaming process engaged 56 organisations over 14 years, drew around 22,000 survey responses, and was led by Monash University's Centre for Research Excellence, the AE-PMOS Society and the patient organisation Verity.

86% of people with the condition and 71% of health professionals supported moving to an accurate, symptom-based name.

What has NOT changed

• The Rotterdam criteria — still any two of three: irregular or absent ovulation, signs of raised androgens, polycystic ovarian morphology
• Diagnosis — the same tests, the same thresholds
• Treatment — the same approaches
• Your diagnosis — if you have PCOS, you have PMOS. It is the same condition
• Your medication — nothing needs changing because of this

If a clinic tells you the rename means you need re-testing or a new treatment plan, that is not correct.

What this means practically

Both names will be in use for about three years. The international guideline currently writes "PMOS/PCOS" in its recommendations, and the 2028 guideline will use PMOS alone. There is an active transition underway, including work with the WHO on diagnostic coding.

So you will see both. Your doctor may still say PCOS. Your reports may still say PCOS. Neither is an error.

Search still works better with "PCOS". Most information online, including most of ours, still uses the older term because that is what people look for. We use PCOS throughout our detailed guides for that reason.

Why the name mattered enough to change

Up to 70% of people with the condition remain undiagnosed. The narrow ovarian framing of the old name is thought to have contributed — both to women not recognising their own symptoms, and to clinicians not considering it.

Around 1 in 8 women of reproductive age are affected. Globally that is roughly 170 million people.

A name that describes the condition accurately is not cosmetic when that many people are going unrecognised.

Where to go next

If you think you may have PMOS or PCOS, our assessment works through the Rotterdam criteria and screens for the other conditions that produce the same pattern — because PMOS is a diagnosis of exclusion, and several conditions that mimic it need very different treatment.

For detail on diagnosis, fertility, diet and long-term health, see our PCOS guides. They carry the same clinical content under the more familiar name.

Terminology update published May 2026. Clinical content per the International Evidence-Based Guideline for the Assessment and Management of PMOS (formerly PCOS).