PCOS, now called PMOS: symptoms, diagnosis and diet
PCOS was officially renamed PMOS in May 2026. What the condition is, how it is diagnosed, the tests that should follow, and what the evidence says about diet.
Reviewed by Emma Carter, Senior Health & Nutrition Editor
Whatever it is called, the pattern is the same: irregular or absent ovulation, higher androgens, and often insulin resistance driving both. Reported prevalence ranges from about 4% to 20% of women of reproductive age depending on which criteria are used (Diagnostics, 2023), and many women go years before anyone names it.
The name itself has now changed. As of May 2026, polycystic ovary syndrome is officially Polyendocrine Metabolic Ovarian Syndrome, or PMOS (Endocrine Society, 2026). Your diagnosis, your tests and your treatment are unchanged. Most clinicians, records and search results still say PCOS, so this guide uses PCOS where that is what you will hear.
Why the name changed
The old name pointed at the wrong thing. Those "cysts" are not cysts in the usual sense, and a paper published alongside the name change found no increase in abnormal ovarian cysts in the condition at all. Reducing a long-term hormonal and metabolic disorder to an ovary finding contributed to missed diagnoses and narrow treatment (Endocrine Society, 2026).
The change came out of 14 years of work led by Professor Helena Teede with the international AE-PCOS Society, 56 patient and professional organizations and more than 22,000 survey responses, published in The Lancet. A three-year transition is planned, with the new name fully in place for the 2028 international guideline update (Endocrine Society, 2026).
In practice, nothing about your care changes. If your notes say PCOS, they are not out of date. If a clinician says PMOS, it is the same condition.
Do you have the signs?
It looks different from one woman to the next. Several of these together are a reason to ask for an assessment:
- Irregular, infrequent or missing periods
- Acne and oily skin, often along the jaw and chin
- Extra hair growth on the face, chest or stomach, or thinning hair on the scalp
- Weight gain around the middle that is hard to shift
- Trouble conceiving
- A raised AMH level, which is common in this condition
What it actually is
Three things travel together: higher androgens such as testosterone, irregular or absent ovulation, and often insulin resistance.
The insulin part matters most day to day. High insulin triggers the pituitary to release luteinizing hormone, which in turn drives androgen secretion (Diagnostics, 2023), and that feeds the skin, hair and cycle symptoms. Steady your blood sugar and you take pressure off the loop.
How it is diagnosed
There is no single test. Under the widely used Rotterdam criteria, an adult diagnosis rests on two of these three, once other causes are ruled out (Diagnostics, 2023):
- Irregular or absent periods
- Signs of high androgens such as acne or excess hair, or raised androgens on a blood test
- Polycystic ovaries on an ultrasound
In adults, an AMH blood test can stand in for that ultrasound. It should not be used as a single test to make the diagnosis, and you should not have both AMH and ultrasound, because doing both drives over-diagnosis (J Clin Endocrinol Metab, 2023).
In adolescents the rules are deliberately different. Ultrasound is not used, because there are no agreed criteria for what a polycystic ovary looks like at that age, and AMH is not used either. For a teenager with some features but not enough for a diagnosis, reassessment is advised at or before eight years after her first period (J Clin Endocrinol Metab, 2023). Irregular cycles in the first years after menarche are often just that.
Because the symptoms overlap with thyroid problems, your doctor may also check your TSH.
The tests that should follow a diagnosis
A diagnosis is the start of the workup, not the end of it. The 2023 international guideline is specific about what should be checked, which is worth knowing so you can ask (J Clin Endocrinol Metab, 2023):
| What | When | Why it is on the list |
|---|---|---|
| Blood glucose status, ideally a 75 g oral glucose tolerance test | At diagnosis, then every 1 to 3 years | The OGTT is the most accurate option here, at any body size |
| Lipid profile | At diagnosis, then based on your results and other risk factors | Cholesterol changes are common and have no symptoms |
| Blood pressure | Every year, and when planning pregnancy or fertility treatment | Same reason, and it affects pregnancy planning |
| Depression and anxiety screening | At diagnosis, repeated based on how things are going | Both are markedly more common with this condition |
| Sleep apnea assessment | If you snore and wake unrefreshed, or feel sleepy in the day | Treatable, and routinely missed in women |
If none of that was offered to you, it is a reasonable thing to raise at your next appointment.
What to do about it
Treatment follows your main concern rather than the diagnosis itself.
| Your main concern | First steps that help | Medical options to discuss |
|---|---|---|
| Irregular periods | Blood-sugar-steady eating, movement | Combined pill |
| Acne and oily skin | The same eating pattern, plus consistent skincare | Combined pill, anti-androgens |
| Excess hair growth | A reliable hair-removal method, plus the above | Combined pill, anti-androgens |
| Fertility | Address insulin; modest weight loss if that is relevant to you | Letrozole, then specialist referral |
| Weight and insulin | Protein, fiber, lower-GI carbohydrates, activity | Metformin |
The guideline is unusually specific about which medication suits which goal. The combined pill is preferred over metformin for excess hair growth and irregular cycles. Metformin is preferred over the pill for metabolic goals, and is considered in adults with a BMI of 25 or above. Taking both together adds little over either alone below a BMI of 30. For fertility, letrozole is first-line for ovulation induction when there is no other infertility factor (J Clin Endocrinol Metab, 2023).
Eating and moving
Lifestyle change is recommended for everyone with the condition, for metabolic health rather than for the scale (J Clin Endocrinol Metab, 2023). A meta-analysis of randomized trials found low-GI eating improved insulin resistance, fasting insulin, cholesterol, waist circumference and total testosterone, while body weight and fasting glucose did not shift (Advances in Nutrition, 2020).
That split is worth sitting with. The eating pattern improved the things that drive the symptoms without moving the number on the scale, which is the opposite of how this condition is usually discussed.
Build meals around protein, fiber and lower-GI carbohydrates, and walk after eating to improve insulin sensitivity.
On weight, the guideline is direct. It tells clinicians to recognize the weight stigma women with this condition meet in healthcare, to be aware of their own biases, and to offer either weight-centered care or weight-inclusive care, which supports healthy change without targeting intentional weight loss, according to what the woman wants (J Clin Endocrinol Metab, 2023). If weight loss is relevant to you, even a modest amount can improve symptoms and ovulation. If it is not what you want to work on, the second version of that care is a legitimate option to ask for.
Why acting early matters
This is not only about periods and skin. The insulin resistance behind it raises the long-term risk of type 2 diabetes, and often affects cholesterol and blood pressure too, which is why those checks are on the list above. Managing it early protects your heart and metabolic health alongside your fertility options, so a diagnosis is worth chasing rather than waiting out, even if the symptoms feel manageable now.
When to see a doctor
See your doctor if:
- Your periods are irregular, infrequent or absent
- Acne or hair changes are bothering you
- You are struggling to conceive
Early diagnosis opens more options and helps protect your long-term health.
What changed in this guide
27 July 2026. Added the May 2026 rename to PMOS and the reasoning behind it. Added the adult and adolescent diagnostic criteria, the screening schedule that should follow a diagnosis, and the medication guidance from the 2023 international guideline, including letrozole as first-line for fertility. Added the guideline's position on weight stigma. This guide has had editorial and evidence review only; it has not been reviewed by a clinician.
Frequently asked questions
Has PCOS been renamed?
Yes. In May 2026 polycystic ovary syndrome was officially renamed Polyendocrine Metabolic Ovarian Syndrome, or PMOS, after a 14-year international process involving 56 patient and professional organizations. Nothing about diagnosis or treatment changes. A three-year transition is planned, with the new name fully in place for the 2028 international guideline update, so both names will be in use for some time.
What is PCOS?
It is a common hormonal and metabolic condition, with reported prevalence ranging from about 4% to 20% of women of reproductive age depending on the diagnostic criteria used. It involves higher androgen levels, irregular or absent ovulation, and often insulin resistance. It is a leading cause of irregular periods and difficulty conceiving.
How is PCOS diagnosed?
There is no single test. In adults, diagnosis rests on two of three findings once other causes are ruled out: irregular or absent periods, signs or blood-test evidence of high androgens, and polycystic ovaries on ultrasound or a raised AMH. In adolescents neither ultrasound nor AMH is used, and reassessment is advised at or before eight years after the first period.
What tests should I have after a PCOS diagnosis?
The 2023 international guideline recommends checking blood glucose status at diagnosis and every one to three years, with a 75 g oral glucose tolerance test as the most accurate option at any body size, plus a lipid profile at diagnosis, blood pressure every year, screening for depression and anxiety, and assessment for sleep apnea if you snore and wake unrefreshed.
What is the best diet for PCOS?
The strongest evidence is for steadying blood sugar and insulin: balanced meals with protein, fiber and lower-GI carbohydrates rather than any extreme diet. A meta-analysis of randomized trials found low-GI eating improved insulin resistance, fasting insulin, cholesterol, waist circumference and total testosterone, although body weight and fasting glucose did not change.
Does PCOS cause weight gain?
It often involves insulin resistance, which makes weight gain easier and loss harder, particularly around the middle. But it occurs at every body size. The 2023 guideline asks clinicians to recognize weight stigma and to offer either weight-centered care or weight-inclusive care, which focuses on healthy change without targeting intentional weight loss, depending on what you want.
References
- Polyendocrine Metabolic Ovarian Syndrome: New name to improve diagnosis and care of condition affecting 170 million women worldwide · Endocrine Society, 2026
- Recommendations From the 2023 International Evidence-based Guideline for the Assessment and Management of Polycystic Ovary Syndrome · Journal of Clinical Endocrinology & Metabolism, 2023
- Polycystic ovary syndrome: pathophysiology and controversies in diagnosis · Diagnostics (Basel), 2023
- Effects of dietary glycemic index and glycemic load on cardiometabolic and reproductive profiles in women with polycystic ovary syndrome · Advances in Nutrition, 2020
- PCOS diet · Johns Hopkins Medicine