A menstrual period that stays away for months, severe acne, or more hair growth than you're used to: these can all be symptoms of PCOS. PCOS is a common hormonal disorder that can affect your menstrual cycle, fertility, metabolism, and mental health.
Since 2026, PCOS has officially had a new name: PMOS, Polyendocrine Metabolic Ovarian Syndrome. In Dutch, this can be translated as polyendocrien metabool ovariumsyndroom. The name PCOS is still widely used and you will therefore likely encounter it frequently for the time being.
But what exactly is PMOS? How do you recognize it, and what can you do about it?
What is PMOS?
PMOS is the new name for the condition previously known as PCOS. It is a hormonal and metabolic disorder that affects women of reproductive age.
With PMOS, various processes in the body can function differently. For example, ovulation often occurs less regularly, the body can produce more androgens such as testosterone, and insulin resistance can play a role.
This can affect, among other things, your:
- menstrual cycle
- skin and hair growth
- fertility
- metabolism
- mental health
PMOS can manifest differently in everyone. One person may primarily have irregular periods, while another may experience more acne, extra hair growth, or difficulty getting pregnant.
Why is PCOS now called PMOS?
The old name Polycystic Ovary Syndrome actually didn't accurately describe what the condition entails.
The word 'polycystic' suggests that people with PCOS have multiple cysts on their ovaries. However, the follicles visible on an ultrasound in some people are follicles and not true cysts.
Moreover, not everyone with the condition has this image on an ultrasound.
Therefore, in 2026, the international community chose the name Polyendocrine Metabolic Ovarian Syndrome, abbreviated as PMOS. This name better emphasizes that various hormonal systems, metabolism, and the ovaries can be involved.
How common is PMOS?
PMOS is one of the most common hormonal disorders in women of reproductive age.
According to international guidelines, the condition is estimated to affect about 10 to 13% of women of reproductive age. That equates to about 1 in 8 women.
Yet, not everyone knows they have PMOS. The symptoms vary widely and can sometimes occur with other conditions.
How do you recognize PMOS?
PMOS can cause various complaints and characteristics. You certainly don't have to have all the symptoms.
Common symptoms include:
- an irregular menstrual period
- menstrual periods that stay away for a long time
- few or no ovulations
- difficulty getting pregnant
- acne or oilier skin
- more hair growth on, for example, the face, chest, or abdomen
- hair loss or thinning hair on the scalp
- weight gain or difficulty with weight management
- signs of insulin resistance
- sadness, anxiety, or insecurity about the body
An irregular menstrual period does not automatically mean you have PMOS, by the way. There are multiple possible causes for changes in your cycle. If you regularly experience this, it is advisable to discuss it with your GP.
Which hormones play a role in PMOS?
PMOS is complex. There isn't one hormone that causes the disorder.
Various hormonal and metabolic processes can play a role simultaneously.
Androgens
Androgens are hormones such as testosterone. Both men and women produce these hormones, but in PMOS, the levels can be elevated.
This can manifest as, for example:
- acne
- more facial or body hair
- hair loss on the scalp
A doctor can assess this based on physical characteristics and possibly blood tests.
Insulin and insulin resistance
Insulin also plays a role in many people with PMOS.
Insulin helps transport glucose from your blood to your cells. In insulin resistance, the cells respond less well to insulin. Your body may then start producing extra insulin.
Insulin resistance can also occur in people with PMOS who are not overweight.
PMOS is also associated with an increased risk of, among other things, type 2 diabetes and other metabolic problems. Therefore, for PMOS, a doctor may also check for things like blood sugar, cholesterol, and blood pressure.
What about estrogen?
Online, PMOS or PCOS is sometimes explained as a form of 'estrogen dominance'.
That is too simplistic.
PMOS is not caused by one hormone being out of balance. According to current scientific insights, it is likely a combination of genetic, hormonal, metabolic, and environmental factors.
Estrogen dominance is therefore not used as a diagnostic feature for PMOS in current international guidelines.
How is PMOS diagnosed?
You cannot diagnose PMOS yourself.
A GP or gynecologist will assess your symptoms and may perform additional tests.
In adults, three important characteristics are looked at:
- an irregular or absent ovulation
- signs of elevated androgens
- a fitting image of the ovaries or, in certain situations, a fitting AMH value
When two of these three characteristics are present and other possible causes have been ruled out, a diagnosis of PMOS can be made.
Do you have both a clear irregular cycle and signs of elevated androgens? Then, according to the international guideline, an ultrasound or AMH test is not always necessary.
Different criteria apply to teenagers. Changes in menstruation and ovaries can also be part of normal puberty. Therefore, ultrasound and AMH are not used in the same way to diagnose PMOS in adolescents.
Can you get pregnant with PMOS?
Yes. PMOS does not mean you are infertile.
Because ovulation may occur less regularly, it can be more difficult to get pregnant.
Some people with PMOS get pregnant without medical help. Others require treatment to stimulate ovulation.
Which treatment is suitable depends on your personal situation and can be discussed with a GP, gynecologist, or fertility specialist.
Even if you have few periods, you can unexpectedly ovulate. Pregnancy is therefore still possible.
What can you do yourself for PMOS?
A healthy lifestyle is an important part of PMOS care.
This does not mean that PMOS is caused by your lifestyle. However, diet, exercise, sleep, and mental health can contribute to your general and metabolic health.
Healthy and varied eating
Online you will find many different so-called PCOS or PMOS diets. For example, low-carb eating or completely avoiding certain foods.
According to current international guidelines, there is no evidence that one specific dietary pattern works better than other healthy dietary patterns for everyone with PMOS.
The most important thing is a healthy, varied, and sustainable eating pattern.
Consider, for example:
- sufficient fruits and vegetables
- whole grain products
- sufficient fiber
- protein-rich foods
- unsaturated fats
Strict or extremely restrictive diets are usually not necessary.
Regular exercise
Regular exercise has various health benefits for PMOS, even if you don't lose weight as a result.
Consider, for example:
- walking
- cycling
- strength training
- running
- swimming
- yoga or other forms of exercise
There isn't one specific sport you should do for PMOS. The most important thing is to choose a form of exercise that suits you and that you can sustain.
Mental health
PMOS can also affect how you feel.
Depressive symptoms, anxiety, body image issues, and eating disorders are more common in people with PMOS. Sleep apnea is also more common.
If you notice you are suffering from this, discuss it with your GP. Mental health is just as much a part of good PMOS care as physical health.
Should you avoid certain foods with PMOS?
You regularly read online that people with PMOS should, for example, completely avoid soy, coffee, dairy, gluten, or carbohydrates.
There is currently insufficient scientific evidence for such general advice.
This does not mean that food cannot affect how you feel. It primarily means that there is no universal list of foods that everyone with PMOS should avoid.
Supplements that promise to 'balance' your hormones are also not automatically proven effective or safe.
If you want to use supplements, discuss this with a doctor or dietitian if in doubt.
What treatment is available for PMOS?
PMOS cannot be definitively cured at this time, but many symptoms can be treated effectively.
Which treatment is appropriate depends on your symptoms, health, and whether you want to have children.
Possible treatments include:
- hormonal contraception to regulate periods
- treatment for acne or excessive hair growth
- metformin for certain metabolic issues
- medication to stimulate ovulation if you want to get pregnant
- lifestyle counseling
Together with a doctor, you can determine which treatment best suits your situation.
When to consult your GP?
It is advisable to contact your GP when:
- your period is very irregular
- your period has been absent for several months
- you suffer a lot from acne or extra hair growth
- you are losing a noticeable amount of hair
- you are trying to get pregnant and it's not working
- you recognize multiple symptoms that may fit PMOS
These complaints can also have other causes. A doctor can therefore investigate what exactly is going on.
