What Is PMOS (Formerly PCOS)? Symptoms, Diagnosis and What to Know

PMOS, or polyendocrine metabolic ovarian syndrome, is a common endocrine condition that affects approximately one in eight women. You probably know it by its former name: polycystic ovary syndrome, or PCOS.

The name officially changed from PCOS to PMOS in May 2026 after an international consensus process concluded that the old name was inaccurate, confusing and didn't adequately describe the condition.

And there was one particularly big problem with it.

PCOS was never simply about ovarian cysts.

PMOS is a complex condition that can affect hormones, metabolism, periods and ovulation, skin and hair, fertility, mental health and long-term health. Different people can experience very different combinations of symptoms.

So let's talk about what PMOS actually is, what signs to look for and how it's diagnosed.

Want to know more about the name change? Read PCOS Is Now PMOS: What the New Name Means and Why It Matters.

What is PMOS?

Polyendocrine metabolic ovarian syndrome (PMOS) is a complex endocrine and metabolic condition that can affect reproductive, hormonal, metabolic and psychological health. It was known as polycystic ovary syndrome (PCOS) until its official name change in 2026.

PMOS is associated with features including irregular ovulation, higher androgen levels and metabolic dysfunction. But there's no single PMOS experience—and not everyone will have every feature or symptom.

That's part of what has historically made the condition so difficult to understand and diagnose.

What does PMOS stand for?

The new name is a mouthful, but each word is there for a reason:

Polyendocrine recognizes that multiple hormonal or endocrine pathways are involved.

Metabolic recognizes the important metabolic features and health risks associated with the condition.

Ovarian reflects the ovarian and reproductive features that can occur without suggesting that the condition is exclusively about the ovaries.

Syndrome means it's a collection of signs, symptoms and characteristics that can present differently from one person to another.

The name was chosen through a global consensus process specifically to better reflect the multisystem nature of the condition. 

In other words, PMOS gives us a much bigger picture than “polycystic ovaries” ever did.

What are the symptoms of PMOS?

PMOS can show up differently from person to person, and symptoms can change over time.

Common signs and symptoms can include:

• irregular, infrequent or absent periods

• irregular or absent ovulation

• excess facial or body hair

• acne

• thinning scalp hair

• difficulty becoming pregnant due to irregular ovulation

• metabolic features, including insulin resistance

• weight gain or difficulty managing weight for some people

PMOS is also associated with increased prevalence of anxiety and depression, and the international guideline recommends greater awareness and screening for both. 

The important part? You don't need to check every box to have PMOS.

And symptoms that can seem unrelated—say, irregular periods and persistent facial hair—can actually be pieces of the same puzzle.

Learn more about the signs and symptoms of PMOS and when to talk to a healthcare provider.

PMOS is about more than your ovaries

The old name put the ovaries front and centre.

The condition itself didn't get that memo.

PMOS can involve several interconnected aspects of health.

Hormones

One of the key features of PMOS is hyperandrogenism, meaning higher levels or effects of androgens such as testosterone.

This can contribute to symptoms including excess facial or body hair, acne and scalp hair thinning.

Metabolic health

Insulin resistance is common in PMOS and can occur regardless of body size.

People with PMOS have an increased risk of impaired glucose tolerance and type 2 diabetes, which is why the international guideline recommends assessing glycemic status at diagnosis and periodically thereafter based on individual risk. 

It's also one reason putting metabolic right in the new name matters.

Periods and ovulation

PMOS can interfere with regular ovulation.

That can mean long menstrual cycles, unpredictable periods or periods that disappear for months at a time. Irregular ovulation can also make becoming pregnant more difficult for some people.

But irregular periods aren't simply an inconvenience. Going for long stretches without menstruating due to chronic anovulation can affect the endometrium, or lining of the uterus, which is one reason cycle management can be an important part of PMOS care.

Mental health

PMOS isn't just physical.

Depression and anxiety are more common among people with PMOS, and the international guideline recommends that healthcare professionals recognize and screen for these concerns.

That's another reason looking at the whole person matters.

Wait. What about the ovarian “cysts”?

Here's one of the stranger facts about a condition that spent decades with polycystic in its name:

PMOS doesn't cause the pathological ovarian cysts most people picture when they hear the word “cyst.”

The characteristic ovarian appearance associated with PMOS involves an increased number of follicles—small structures in the ovary involved in egg development.

Those aren't the same thing as pathological ovarian cysts.

And you don't need this ovarian appearance to have PMOS. 

That misunderstanding wasn't harmless. The international consensus behind the name change found that the term PCOS contributed to confusion about the condition, delayed diagnosis, fragmented care and stigma. 

After decades of explaining that you don't actually need ovarian cysts to have something called polycystic ovary syndrome, medicine finally decided the name might be part of the problem.

Fair.

What causes PMOS?

The short answer: there isn't one single known cause.

Current evidence suggests PMOS is a complex condition involving interactions between genetic, hormonal, metabolic and environmental factors.

There is a strong genetic component, which helps explain why PMOS can occur in families. Insulin resistance and androgen excess also play important roles in the condition, but PMOS isn't caused by one hormone being “out of balance” or by one lifestyle factor. 

And despite the abundance of PMOS advice on social media, you didn't give yourself PMOS by eating the wrong foods, being stressed or failing to exercise enough.

Lifestyle factors can influence symptoms and long-term health and can be part of evidence-based PMOS management. That's very different from saying they caused the condition.

How is PMOS diagnosed?

There's no single test that says yes, you have PMOS.

In adults, diagnosis is generally based on the presence of at least two of three key features, after other possible causes have been excluded:

1. Ovulatory dysfunction
This may show up as irregular, infrequent or absent periods.

2. Clinical or biochemical hyperandrogenism
This means signs of elevated androgen activity—such as excess facial or body hair—or elevated androgen levels identified through appropriate blood testing.

3. Polycystic ovarian morphology
This can be assessed using ultrasound or, in adults, anti-Müllerian hormone (AMH) may be used as an alternative for defining polycystic ovarian morphology.

And here's an important point: an ultrasound isn't always necessary.

If an adult already has irregular menstrual cycles and hyperandrogenism, ovarian ultrasound or AMH isn't required to make the diagnosis under the international guideline. 

The diagnostic process is also different for adolescents. Because irregular cycles and some features of ovarian development can be normal during puberty, the criteria are deliberately more cautious. Ultrasound and AMH are not recommended for diagnosing PMOS in adolescents. 

A healthcare provider may also use your medical history, physical examination and blood tests to evaluate your symptoms and rule out other conditions.

So no, “we didn't see cysts on your ultrasound” does not automatically rule out PMOS.

How is PMOS treated?

There isn't one universal PMOS treatment because there isn't one universal PMOS experience.

Management should be individualized around your symptoms, health risks, priorities and whether pregnancy is currently a goal.

Depending on the person, evidence-based management may include lifestyle interventions, hormonal contraception, medications such as metformin, treatments for excess hair growth or acne, psychological support and fertility treatments when needed.

Importantly, PMOS care shouldn't begin and end with fertility.

Long-term metabolic health, cardiovascular risk factors, mental health, menstrual health and quality of life all matter too.

And if you've encountered approximately 47 different supplements on TikTok that supposedly “balance your hormones,” you may understandably have questions.

[Internal link: Read PMOS Treatment and Management: What Does the Evidence Say? link when live https://getjoni.com/blogs/blog/what-is-pcos-how-can-naturopathy-help]

PMOS and your period

Irregular periods are one of the most recognizable features of PMOS—but there's no single thing called a “PMOS period.”

Some people have very long cycles. Some miss periods altogether. Some experience unpredictable bleeding. Others may have relatively regular cycles while experiencing other features of the condition.

Tracking your cycle can be useful because it gives you and your healthcare provider information about how frequently you're menstruating and whether ovulatory dysfunction could be part of what's happening.

And when your period refuses to consult the calendar before arriving, having period care that works for unpredictable flow certainly doesn't hurt.

Read more about PMOS and your period, including what to expect and how to manage unpredictable cycles.

Can PMOS be cured?

There currently isn't a cure for PMOS, but its symptoms and associated health risks can be managed.

And what you need from PMOS care may change throughout your life.

At one point, the priority might be acne or irregular periods. Later it might be fertility. At another stage, metabolic or cardiovascular health may take centre stage.

That's why PMOS management should be an ongoing conversation rather than a single prescription handed over at diagnosis.

What should I do if I think I have PMOS?

If you're experiencing symptoms that could be associated with PMOS, talk to a qualified healthcare provider.

It can help to bring information about your menstrual cycles, symptoms, medications and family history to the appointment. Write down questions beforehand, particularly if there's a lot you want to cover.

And if you're told you can't have PMOS because you don't have ovarian cysts, it's reasonable to ask how your symptoms fit the current diagnostic criteria or seek another medical opinion.

PMOS can overlap with other conditions, so proper assessment and exclusion of other potential causes are important.

The bottom line on PMOS

PMOS is common. It's complex. And for far too long, its name made it sound like a condition primarily involving ovarian cysts.

We now know better.

PMOS can affect hormones, metabolism, periods, fertility, skin, hair, mental health and long-term health—and no two experiences look exactly alike.

The name may be new. The condition isn't.

But understanding the whole picture is a pretty good place to start.

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