Polycystic ovary syndrome (PCOS) is now called polyendocrine metabolic ovarian syndrome (PMOS). The new name was announced in May 2026 to better reflect that the condition involves hormones, metabolism and the ovaries, rather than ovarian “cysts” alone.
The name has changed, but the condition itself has not. The way PMOS is diagnosed and managed remains based on the existing international guideline, and you will continue to see both PCOS and PMOS used during the transition.
PMOS is a common long-term hormonal and metabolic condition that can affect periods, ovulation, skin and hair, fertility, mental health and long-term health. Research commonly reports prevalence in women, with estimates of around 10 to 13% of reproductive-aged women. In this article, we generally use “people” because anyone with ovaries can experience these symptoms and health concerns.
Key takeaways
- PCOS was renamed polyendocrine metabolic ovarian syndrome (PMOS) in May 2026.
- The name changed, but the underlying condition, diagnostic approach and current management recommendations have not.
- You do not need ovarian cysts to have PMOS.
- There is no single test. Diagnosis is based on a combination of features after other possible causes have been considered.
- PMOS can affect people of any body size.
- There is currently no cure, but symptoms and long-term health risks can often be managed.
- Regular health checks are an important part of PMOS care, including assessment of blood glucose, cholesterol, blood pressure and mental health.
- PMOS can affect ovulation and fertility, but it does not mean you cannot become pregnant.
What is PMOS?
PMOS is a complex condition involving hormones, metabolism and ovarian function. It can affect menstrual cycles, ovulation, androgen levels, insulin sensitivity and several aspects of long-term health.
The old name, polycystic ovary syndrome, was misleading because you do not need ovarian cysts to have the condition.
The multiple small structures sometimes seen on an ultrasound are usually immature ovarian follicles, which are small fluid-filled sacs containing developing eggs. They are not the same as abnormal ovarian cysts.
Some people with PMOS have these ultrasound changes and others do not. Likewise, someone can have multiple ovarian follicles on a scan without having PMOS.
Why was PCOS renamed PMOS?
The new name, polyendocrine metabolic ovarian syndrome, was announced on 12 May 2026 following a 14-year international consensus process led by Monash University's Professor Helena Teede.
The process involved dozens of patient, professional and research organisations as well as input from more than 22,000 people.
The old name placed a great deal of emphasis on the ovaries and “cysts”, even though PMOS affects much more than reproductive health. The new name is intended to better represent the condition:
- Polyendocrine reflects the involvement of multiple interacting hormonal systems.
- Metabolic recognises links with insulin resistance, glucose regulation and cardiovascular risk factors.
- Ovarian reflects the role of ovarian function, ovulation and follicle development.
The new terminology is expected to be fully incorporated when the international guideline is updated in 2028. Until then, it is normal to see both PCOS and PMOS used by healthcare professionals, researchers and health services.
What are the symptoms of PMOS?
PMOS can look very different from one person to another. Some people have several symptoms, while others have only one or two.
Common symptoms and experiences can include:
- irregular, infrequent or absent periods
- difficulty predicting ovulation. Irregular ovulation can sometimes mean an egg isn’t released at all. Read what anovulation means.
- extra facial or body hair, known as hirsutism
- acne or oily skin
- thinning scalp hair
- difficulty conceiving
- weight gain or difficulty managing weight, although PMOS occurs across all body sizes
- anxiety, depression or changes in body image
Heavy or prolonged bleeding can also occur, particularly when cycles are irregular, but having heavy periods does not necessarily mean you have PMOS.
Many other conditions can cause similar symptoms, so diagnosis is based on the overall pattern rather than one symptom alone.
What causes PMOS?
The exact cause of PMOS is not fully understood.
Genetics appear to play an important role, and hormonal, metabolic and ovarian changes can influence each other. Insulin resistance is common in PMOS and can contribute to higher insulin and androgen levels in some people, but insulin resistance itself is not one of the diagnostic criteria.
Routine insulin blood testing is not recommended as a way of diagnosing PMOS.
Sleep, physical activity, nutrition and other modifiable factors may affect symptoms and long-term health, but they do not mean someone caused their PMOS.
How is PMOS diagnosed?
There is no single blood test, ultrasound or symptom that confirms PMOS.
For adults, diagnosis generally requires two of the following three features after other conditions that can cause similar symptoms have been considered:
- Irregular menstrual cycles or ovulatory dysfunction. For adults more than three years after their first period, cycles shorter than 21 days, longer than 35 days or fewer than eight cycles per year are considered irregular in the international guideline.
- Clinical or biochemical hyperandrogenism. This may mean signs such as excess facial or body hair, or higher androgen levels on blood testing.
- Polycystic ovarian morphology on ultrasound or an elevated anti-Müllerian hormone (AMH) level. AMH can be used as an alternative to ultrasound in adults in appropriate circumstances.
If both irregular cycles and hyperandrogenism are already present, an ultrasound or AMH test is not needed to establish the diagnosis.
AMH should not be used as a standalone PMOS test, and using both AMH and ultrasound simply to confirm the same diagnostic feature is generally unnecessary.
If you take the combined oral contraceptive pill, tell your doctor because it can make some hormone test results more difficult to interpret.
How is PMOS diagnosed in teenagers?
Diagnosis is more cautious during adolescence because irregular cycles and acne can be common during puberty.
For teenagers, the international guideline requires both irregular menstrual cycles and hyperandrogenism. Ultrasound and AMH are not recommended for diagnosis during adolescence because reliable diagnostic criteria have not been established for these tests at this age.
Cycle patterns are also interpreted according to how long it has been since periods started. Irregularity is expected during the first year after the first period. More than one year after periods begin, any single cycle longer than 90 days warrants assessment.
It is also worth seeking medical advice if a first period has not occurred by age 15 or more than three years after breast development began.
If a teenager has some features of PMOS without meeting the full diagnostic criteria, a healthcare professional may recommend monitoring and reassessment later.
How is PMOS managed?
There is currently no cure for PMOS, but symptoms and long-term health risks can often be managed.
Treatment depends on your symptoms, priorities, health risks and whether pregnancy is part of your plans.
Lifestyle and wellbeing
The international guideline recommends healthy lifestyle behaviours for everyone with PMOS, with benefits possible even without weight loss.
No single diet or type of exercise has been shown to be best for PMOS. A sustainable approach that suits your preferences, culture, health and circumstances is more useful than following a rigid “PCOS diet” or exercise program.
Weight stigma can affect healthcare experiences, and PMOS occurs across all body sizes. You can ask for care that focuses on your health goals rather than weight alone.
Disordered eating and eating disorders are also more common in people with PMOS, so tell your healthcare professional if food, weight or body image is becoming difficult.
Medicines
Medication depends on which aspects of PMOS you are managing.
- The combined oral contraceptive pill may be recommended for irregular cycles and symptoms related to higher androgen activity, such as excess hair growth. It is not suitable for everyone.
- Metformin may be recommended particularly when metabolic features are a concern.
- Hair and skin treatments may include cosmetic or laser hair reduction and, in some situations, anti-androgen medicines. Effective contraception is important with some anti-androgens because they can affect a developing pregnancy.
- Fertility medicines may be used when ovulation is infrequent or absent and pregnancy is the goal.
Some medicines used in PMOS care are prescribed off-label. Your prescriber can explain why a particular medicine is being recommended as well as its likely benefits and risks.
PMOS, periods and heavy bleeding
Irregular, infrequent or absent periods are common reasons people with PMOS seek medical assessment.
Other conditions can also change your cycle, including pregnancy, thyroid conditions, stress, perimenopause and some medicines, so it is worth getting persistent cycle changes assessed rather than assuming PMOS is the cause.
Very long gaps between periods can allow the lining of the uterus to build up. This is one reason persistent absent or very infrequent periods should not be ignored.
If bleeding is heavy, prolonged or disruptive, ask for it to be assessed. Our guide to how much you bleed during your period explains common signs of heavy menstrual bleeding.
If you are managing heavier flow while waiting for medical assessment, you can also compare menstrual cups for heavy periods.
Tracking cycle length, bleeding and symptoms can help you explain what has been happening at an appointment. You can use our free downloadable period tracker to record these changes.
PMOS, fertility and pregnancy
PMOS can make conception more difficult for some people because ovulation may happen irregularly or not at all. It does not mean that pregnancy is impossible.
Many people with PMOS conceive naturally, while others may benefit from fertility support.
When infertility is caused by infrequent or absent ovulation and there are no other infertility factors, the international guideline recommends letrozole as the first-choice medicine for inducing ovulation. In some countries or situations it may be prescribed off-label, so your fertility specialist can explain how it is used.
Pregnancy with PMOS is considered higher risk because rates of some complications are increased, including gestational diabetes, high blood pressure, pre-eclampsia, miscarriage and preterm birth.
These are increased risks, not certainties. If you are planning a pregnancy, ask your healthcare professional whether you should have your blood pressure and glucose checked beforehand and make sure your antenatal team knows about your PMOS diagnosis.
PMOS and mental health
Anxiety and depression are more common in people with PMOS.
Living with unpredictable periods, acne, unwanted hair growth, scalp hair changes, fertility concerns, weight stigma or a delayed diagnosis can also affect wellbeing and body image.
Mental health is therefore considered part of PMOS care rather than an unrelated issue. Current guidelines recommend screening for depression in adults and adolescents with PMOS and assessing anxiety in adults.
If PMOS is affecting your mood, eating, body image or day-to-day wellbeing, speak with a GP or mental health professional. Our article on how hormones can affect mental health may also be useful.
Which health checks are recommended?
PMOS is associated with increased risks of impaired glucose tolerance, type 2 diabetes, cardiovascular risk factors, sleep apnoea and endometrial hyperplasia.
The risk of endometrial cancer is also increased compared with people without PMOS, although the absolute risk remains low.
Recommended health monitoring can include:
- Blood glucose assessment at diagnosis, with reassessment generally every one to three years depending on individual risk.
- A lipid or cholesterol profile at diagnosis, with repeat testing based on the results and overall cardiovascular risk.
- Blood pressure checked at least yearly.
- Mental health screening for depression and anxiety.
- Assessment for sleep apnoea symptoms such as snoring, waking unrefreshed or excessive daytime sleepiness.
Your GP can advise how often these checks are appropriate for you.
When should you see a healthcare professional?
Consider making an appointment with a GP or other qualified healthcare professional if you have:
- consistently irregular periods
- no periods for several months
- heavy, prolonged or disruptive bleeding
- facial or body hair growth, acne or scalp hair thinning that concerns you
- difficulty conceiving
- low mood, anxiety or significant changes in eating or body image
- symptoms that are affecting your everyday life
Seek prompt medical assessment if androgen-related symptoms, such as facial or body hair growth, develop suddenly or progress rapidly, as this can sometimes point to another cause.
You do not need every symptom on a checklist before asking for help.
If you are unsure how to begin the conversation, our guide to talking to a doctor about intimate health concerns may help you prepare.
Frequently asked questions
Is PCOS now called PMOS?
Yes. In May 2026, an international consensus process formally recommended the new name polyendocrine metabolic ovarian syndrome, or PMOS. You will continue to see both PCOS and PMOS used while health services, researchers and guidelines transition to the new terminology.
Can you have PMOS without ovarian cysts?
Yes. Ovarian cysts are not required for a PMOS diagnosis. The structures sometimes seen on ultrasound are usually multiple immature follicles rather than true ovarian cysts, and some people with PMOS do not have this ultrasound appearance at all.
Has treatment changed because PCOS was renamed PMOS?
No. The name change does not mean that existing diagnoses are invalid or that treatment has suddenly changed. Current diagnosis and management continue to follow the international guideline while the PMOS terminology is introduced.
Can you have PMOS at a lower weight?
Yes. PMOS occurs across all body sizes. Metabolic and glucose-related risks can still be present in people who are not in a higher-weight body, which is why appropriate health checks are recommended regardless of weight.
Can PMOS be cured?
There is currently no cure for PMOS, but symptoms and associated health risks can often be managed. The most useful approach depends on your symptoms, priorities, health risks and pregnancy plans.
Do you need an ultrasound to be diagnosed with PMOS?
Not always. If an adult already has both irregular menstrual cycles and clinical or biochemical hyperandrogenism, an ultrasound or AMH test is not required to meet the diagnostic criteria.
Can AMH diagnose PMOS?
AMH can be used as an alternative to ultrasound when assessing polycystic ovarian morphology in adults, but it should not be used as a standalone diagnostic test. AMH is not recommended for diagnosing PMOS in adolescents.
Do supplements such as inositol help PMOS?
Inositol may be considered for some people, but current guidelines describe its clinical benefits as limited. There is not enough evidence to recommend one specific type, dose or combination. Metformin has stronger evidence for some metabolic outcomes. Tell your healthcare professional about any supplements you take so they can be considered alongside your other treatment.
The bottom line
PCOS is now called PMOS, but the condition itself has not changed. The new name better reflects the fact that PMOS affects hormones, metabolism and ovarian function rather than being defined by ovarian “cysts”.
Diagnosis is based on a combination of menstrual or ovulatory changes, androgen activity and, when needed, ovarian morphology or AMH testing in adults. Treatment is individual and may include lifestyle support, medication, fertility care and mental health support.
If you have irregular or absent periods, heavy bleeding, androgen-related symptoms or fertility concerns, a GP is a good place to start. Bringing a record of your cycles and symptoms can make that conversation easier, and our free period tracker can help.
This article provides general information and is not a substitute for personalised medical advice or diagnosis.
Sources and further reading
- Teede HJ et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome: a multistep global consensus process. The Lancet, 2026.
- Monash University. PMOS: new name to improve diagnosis and care.
- Monash University. International evidence-based guideline for PMOS.
- Teede HJ et al. Summary of the 2023 international evidence-based guideline: an Australian perspective. Medical Journal of Australia, 2024.
- American Society for Reproductive Medicine. Recommendations from the international evidence-based guideline for PMOS.
- Jean Hailes for Women's Health. Polyendocrine metabolic ovarian syndrome (PMOS).
- Better Health Channel. Polyendocrine metabolic ovarian syndrome (PMOS).