PCOS is now PMOS
On 12th May 2026 The Lancet published an article announcing that Polycystic Ovary Syndrome (PCOS) has now been renamed as Polyendocrine Metabolic Ovary Syndrome (PMOS).
This is an unprecedented change, and took 14 years of global collaboration between medical experts and those with lived experience of the condition.
So why the change?
In The Lancet article they state that 1 in 8 women is affected by the condition, but the term PCOS was inaccurate as it implied that ovarian cysts were the biggest and main problem or cause. And it did not take into account the main endocrine and metabolic features.
And this inaccuracy is one of the main things that contributed to delayed diagnosis and incorrect treatment.
As the charity Verity say:
Names matter. They shape knowledge, care and equity. Getting the right name is a step toward getting the right care.
So what prompted the changes and what does this mean?
Old name PCOS:
- Named after cysts that don’t exist (they’re follicles not cysts) and not everyone gets these. They’re a symptom and not the cause.
- The name ignores the endocrine (hormonal) and metabolic features of the condition.
- It was viewed as a purely gynaecological and fertility condition.
- Serious associated health risks were not taken into account.
- Due to the inaccurate investigations for a diagnosis (looking for cysts as an example) it led to longer diagnosis time and often up to 70% were left undiagnosed.
New name PMOS:
- No mention of cysts – as there is no increased risk of ovarian cysts.
- Takes into account that it’s a whole body condition and for the lifetime, not just reproductive years.
- The terms ‘endocrine’ and ‘metabolic’ show it’s not just reproductive/gynae issue.
- These terms also takes into account the associated health risks.
With the correct guidance this should lead to better investigations and overall clinical care.
Breaking it down this is what it stands for:
P = Polyendocrine
M = Metabolic
O = Ovarian
S = syndrome
Polyendocrine
Endocrine refers to the hormone system. Poly means many. So together it means many hormones or glands. So this takes into account that this condition affects many different hormones and hormone glands around the body.
Metabolic
Metabolic means to do with metabolism.
Metabolism is a group of chemical reactions, or changes, that happen in the cells of the body that are necessary for life. Some metabolic reactions let cells break down food. Others let cells grow or repair themselves. We have thousands of metabolic reactions happening inside the body at any one time.
Anything that disturbs these normal metabolic reactions can lead to disorders such as diabetes, heart disease, weight gain etc.
Ovarian
Related to the ovaries as this condition does affect the reproductive hormones and have an impact on periods and fertility.
Syndrome
Means a grouping or collection of symptoms or signs that happen together due to a particular condition/disease.
Things to bear in mind with the changes
There is a 3 year transition period, where the terms PCOS and PMOS will be used alongside each other as process and advice is updated.
So you’ll probably see the terms PCOS and PMOS used alongside each other for the time being.
In the UK and internationally new PMOS guidelines are coming and will be used to update clinicians and the public.
Advocacy groups and patients will keep pushing for changes and legislation for research, better care pathways etc.
For any support please go to the charity Verity. Their website has a whole lot of information and support for anyone who needs it.