In May 2026, polycystic ovary syndrome (PCOS) was officially renamed polyendocrine metabolic ovarian syndrome (PMOS) following an international consensus process involving people living with the condition, researchers, healthcare professionals and patient organizations around the world.
And no, this isn't medical experts changing an acronym just to make everyone's Google searches more complicated.
The problem is that PCOS was never a particularly accurate name for the condition it described.
One such inaccuracy is the “cysts” part of the name, because they aren't actual pathological cysts, meaning they aren't harmful, abnormal growths or diseased masses. They are just normal, undeveloped egg follicles that stalled out due to a hormone imbalance.
More importantly, focusing so heavily on ovaries has helped obscure something researchers and people living with PCOS have understood for years: this is a complex condition involving much more than the ovaries.
So, meet PMOS.
Same condition. Better name. And potentially, a much better way of understanding it.
First: what does PMOS stand for?
PMOS stands for polyendocrine metabolic ovarian syndrome.
It is the new name for the condition previously known as polycystic ovary syndrome, or PCOS.
According to the international consensus published in The Lancet, the terminology was chosen because it more accurately reflects the multiple systems involved in the condition.
Let's break that name down.
Polyendocrine recognizes that multiple hormonal or endocrine pathways can be involved.
Metabolic recognizes the important metabolic features and health risks associated with the condition, including insulin resistance and increased risks of impaired glucose tolerance and type 2 diabetes.
Ovarian keeps the reproductive and ovarian component in the picture—without pretending the ovaries are the whole story.
And syndrome remains because PMOS describes a collection of features that can show up differently from person to person.
That last part is important. There isn't one universal PMOS experience. If PMOS is new to you, start with our complete guide to PMOS (formerly PCOS) for symptoms, diagnosis, causes and treatment.
Wait. PCOS doesn't actually cause ovarian cysts?
Here's where things get confusing.
Despite the name polycystic ovary syndrome, PCOS was never simply a condition in which someone develops a bunch of ovarian cysts.
The "polycystic" appearance associated with PCOS refers to multiple small follicles in the ovaries, not the pathological ovarian cysts most people imagine when they hear the word cyst.
According to Monash University researchers involved in the name change, there is actually no increase in abnormal ovarian cysts associated with the condition.
That's a pretty significant problem when polycystic has been sitting right there in the name for decades.
It also created another misconception: that you have to have "cysts" on your ovaries to have PCOS.
You don't.
Ovarian morphology can be part of the diagnostic picture in adults, but it is not universally required for diagnosis. Current international guidelines use combinations of ovulatory dysfunction, clinical or biochemical hyperandrogenism, and polycystic ovarian morphology or, in adults, anti-Müllerian hormone (AMH), after other causes have been excluded.
In adolescents, ovarian morphology isn't recommended as a diagnostic criterion because it isn't specific enough during this stage of development.
In other words: a syndrome named after ovarian "cysts" doesn't require ovarian cysts.
You can see why people had notes.
Why change PCOS to PMOS now?
This wasn't a decision someone made during a particularly ambitious committee meeting.
The movement to rename PCOS has been developing for years.
The international name-change initiative ultimately involved 56 academic, clinical and patient organizations, people with lived experience and multidisciplinary healthcare professionals from around the world.
The process included global surveys, Delphi consensus methods, workshops and analysis of potential terminology. The published consensus paper reports 14,360 responses in its new global surveys, while the broader patient-focused name-change initiative accumulated more than 22,000 survey responses across the process.
Most importantly, people living with PCOS weren't an afterthought.
The American Society for Reproductive Medicine says women with the condition were the biggest drivers behind the change.
The group established some sensible requirements for a new name: it needed to be scientifically accurate, understandable, culturally appropriate, feasible to implement and less likely to contribute to stigma.
Ultimately, polyendocrine metabolic ovarian syndrome was chosen.
The bigger problem with "PCOS"
Getting rid of "cystic" fixes one obvious problem.
The other two words—polycystic ovary—created a subtler one: they made this sound overwhelmingly like an ovarian or reproductive condition.
PMOS is much broader than that.
The condition can involve:
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reproductive,
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endocrine,
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metabolic,
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dermatological, and
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psychological health.
People may experience:
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irregular or absent periods,
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excess hair growth,
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acne,
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hair thinning
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fertility challenges, and
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metabolic risk factors.
PMOS can look very different from one person to another. Our guide to the signs and symptoms of PMOS takes a closer look at what to watch for—and why the condition can sometimes be missed.
The international guideline also recognizes increased risks or prevalence of conditions including:
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impaired glucose tolerance,
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type 2 diabetes,
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cardiovascular risk factors,
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obstructive sleep apnea,
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anxiety and depression.
That doesn't mean everyone with PMOS will experience all—or even most—of these things.
It means we need to stop reducing a complex health condition to periods, fertility and ovaries.
And that's where this name change starts to become much more than semantics.
Here are five signs you may have PMOS.
Why does changing the name actually matter?
Fair question.
Changing the name to PMOS (Polycystic Morphologic Ovarian Syndrome, or Polyfollicular Ovarian Syndrome) doesn't magically make symptoms disappear.
It doesn't automatically shorten specialist waitlists.
And it certainly doesn't undo decades of people being dismissively told to "lose weight, go on the pill, and come back when you want to get pregnant"—a standard line of advice that treats a complex, lifelong metabolic disorder as merely a temporary fertility inconvenience.
A name change might fix the medical terminology, but it doesn't instantly fix the deeply ingrained systemic issues in women's healthcare or the frustration of patients who have spent years fighting for proper treatment.
That said, names can influence how we understand disease.
They influence what patients search for, what healthcare providers look for, what researchers study, and even where health conditions sit within healthcare systems and disease classifications.
The international consensus authors specifically noted that the old name could contribute to misunderstanding, delayed diagnosis, fragmented care and stigma.
If a condition is understood primarily as an ovarian problem, it's easier to overlook the metabolic picture.
If it's understood primarily as a fertility problem, it's easier to overlook someone's health when pregnancy isn't their goal.
And if the name itself suggests you need ovarian cysts to qualify, it's not difficult to see how confusion can begin before someone even gets through the doctor's door.
PMOS puts endocrine and metabolic health right in the name.
That's not a cure.
But it is a correction.
Does PMOS change how the condition is diagnosed?
Not immediately.
This is important because a new name can make it sound as though scientists have discovered a new disease or completely rewritten the diagnostic criteria.
They haven't.
The 2023 International Evidence-Based Guideline has been updated to use PMOS terminology, but its recommendations and clinical content remain unchanged as a result of the name change.
So if you were diagnosed with PCOS, you haven't suddenly been undiagnosed.
You now have PMOS.
And if your medical records still say PCOS? That's expected, too.
Just as a name change doesn’t change how you experience this condition, your period care can’t cure it either. And yet mindful period care choices may help manage PMOS symptoms.
Are doctors going to start calling it PMOS immediately?
Some will. Some won't. That’s the simple reality of healthcare implementation. But it is a start as the change rolls out gradually across clinical practice, research, education, health systems and disease classification.
The current international guideline now uses PMOS, formerly PCOS, or PMOS/PCOS during the transition. The next International Evidence-Based Guideline, expected in 2028, will use PMOS as the standard terminology.
So we're likely to see both terms for a while.
That's also why you'll see us use both PMOS and PCOS in this article and across some of our existing resources. Millions of people know their condition as PCOS, and making accurate health information harder to find in the name of using the newest terminology would rather defeat the purpose.
If I was diagnosed with PCOS, do I now have PMOS?
Yes.
PMOS is not a newly discovered condition and it doesn't replace PCOS with a different diagnosis. It's the new name for the same syndrome.
You don't need to be re-diagnosed because the acronym changed.
If you have questions about what the updated terminology means for your individual health, diagnosis or treatment, that's a conversation to have with your healthcare provider.
How common is PMOS?
Very.
Current estimates suggest PMOS affects approximately one in eight women, or more than 170 million women worldwide.
Yet despite being one of the most common endocrine conditions affecting reproductive-aged women, diagnosis and care have historically been inconsistent.
Which makes getting the basics right—including the name—a bigger deal than it might initially sound.
What does PMOS mean for your period?
Irregular periods are one of the most recognizable signs of PMOS, but there's no single "PMOS period." Some people have infrequent periods, some go months without one, and others experience heavy or unpredictable bleeding.
Understanding what's happening with your cycle can be one part of understanding PMOS. Read more about PMOS and your period, including practical considerations for choosing period care when your cycle doesn't exactly stick to the calendar.
A better name won't solve everything. But words matter.
Women's health has a rather impressive history of naming, describing and studying conditions without always centring the people actually living with them.
The PMOS name change is notable because lived experience was deliberately built into the process.
People with the condition helped say: this name doesn't accurately describe what's happening to us. Researchers listened. That's worth paying attention to.
PMOS may not be a perfect acronym, either! And we'll probably all accidentally call it PCOS for quite some time.
But the new name does something the old one failed to do: it tells us to look beyond the ovaries: at hormones. At metabolic health. At reproductive health. At the whole person.
Turns out, there was always more to PCOS than cysts. Now the name finally reflects it.
References and further reading
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Monash University. Polyendocrine Metabolic Ovarian Syndrome: New name to improve diagnosis and care of condition affecting 170 million women worldwide
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Monash Centre for Health Research and Implementation. International Evidence-Based Guideline for the Assessment and Management of PMOS
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American Society for Reproductive Medicine. PCOS is Now PMOS: Understanding the Name Change
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Endocrine Society. Polyendocrine Metabolic Ovarian Syndrome: New name to improve diagnosis and care