Everything You Need to Know About PCOS

Polyendocrine metabolic ovarian syndrome (PMOS) is the condition you may still know as polycystic ovary syndrome (PCOS). It’s one of the most common hormonal conditions, affecting around 1 in 8 women. But despite the old name, it has never been just about the ovaries.

PMOS can affect your periods, ovulation, skin, hair, metabolism, fertility, sleep and mental health. It can also look completely different from one person to another. One person may have very irregular periods and excess facial hair, while another has acne, fairly regular cycles and no obvious symptoms until they start trying to conceive.

That variation is one of the reasons PMOS can be difficult to recognise and why diagnosis is sometimes delayed. Whether you have recently been diagnosed, think your symptoms could be linked to PMOS, or have been living with the condition for years, this guide covers PCOS symptoms, diagnosis, fertility, treatment, nutrition and long-term health.

Quick facts: 

• PMOS is the new name for PCOS. The condition hasn’t changed, the name has.
• Around 10–13% of women of reproductive age are thought to have PMOS, and up to 70% may be undiagnosed.
• Symptoms can include irregular periods, acne, excess facial or body hair, scalp hair thinning, fertility difficulties and metabolic changes.
• PCOS is associated with an increased risk of conditions including type 2 diabetes, sleep apnoea and endometrial problems.
• There is no single test for PCOS.
• In adults, diagnosis is usually based on meeting 2 out of 3 recognised criteria, once other possible causes have been ruled out.
• AMH can now be used as an alternative to ultrasound when assessing polycystic ovarian morphology in adults, but AMH cannot diagnose PCOS on its own.
• PCOS can affect fertility, but having PCOS does not mean you can’t get pregnant.
• There is no single “PCOS diet” or one treatment that works for everyone. Management should be based on your symptoms, health and goals.

If you are wondering whether your symptoms could be linked to PCOS, Hertility’s Advanced Hormone and Fertility Test can help build a clearer picture of your hormones, cycle and symptoms to help you understand what’s going on.

Why was PCOS renamed PMOS?

On 12 May 2026, the international PCOS community officially adopted the name polyendocrine metabolic ovarian syndrome, or PMOS.

The previous name, polycystic ovary syndrome, could be misleading for several reasons.

Firstly, the “cysts” associated with PCOS are not typical ovarian cysts. They are usually small ovarian follicles containing immature eggs. Secondly, you can have the condition without having polycystic-looking ovaries at all.

Most importantly, the old name placed the emphasis on the ovaries when the condition can affect much more than reproductive health, including metabolism, hormones, mental wellbeing and long-term health.

The new name was developed through an international process involving healthcare professionals, researchers and people living with the condition.

If you already have a PCOS diagnosis, you do not need to be diagnosed again. Your diagnosis has not changed. You will also continue to see the term PCOS in medical records, research and online searches, which is why we use both PCOS and PMOS throughout this guide.

Read more: PCOS has been renamed PMOS — here’s what that means for you.

How common is PCOS?

The World Health Organization estimates that PMOS affects up to 13% of women of reproductive age, making it one of the most common hormonal conditions worldwide, and that up to 70% of those affected may not know they have it. In the UK, the NHS estimates it affects about 1 in every 10 women.

Part of the problem is that there’s no single way it presents. Diagnosis can also take time. In one international study, over a third of people with PCOS waited more than two years for a diagnosis, and almost half saw three or more health professionals before getting one.

What are the common symptoms of PCOS?

PCOS symptoms can affect your menstrual cycle, skin, hair, metabolism, sleep, mood and fertility. You do not need to have every symptom to have the condition.

Menstrual cycle-related symptoms

One of the most common features is irregular ovulation. which can make periods longer, unpredictable or absent for months, sometimes with heavier or prolonged bleeding after a long gap. 

You may ovulate later, less often, or not at all in some cycles (an anovulatory cycle). In adults more than three years past their first period, cycles shorter than 21 days, longer than 35 days, or fewer than eight a year are considered irregular. Having regular periods don’t completely rule out PCOS, though more on that below. 

If you want to understand your own cycle, see our guide Menstrual Cycle 101: Your Complete Guide to How Your Cycle Works

Skin and hair-related symptoms

Higher androgen activity (androgens include hormones like testosterone) can contribute to acne, oily skin, excess facial or body hair (known as hirsutism), often on the chin, upper lip, chest, abdomen or back, and scalp hair thinning, often noticed as a widening parting. 

Hair-growth patterns vary a lot between individuals and ethnic groups, which matters when symptoms are assessed. Some people also develop acanthosis nigricans, darker, thicker, velvety-looking skin around the neck or underarms, which can be linked to insulin resistance.

To find out more about how hormones affect your skin, read our guide to skin and hair changes.

Weight gain or difficulty losing weight

Some people experience weight gain or find weight harder to manage, but you don’t need to be overweight to have PCOS. It affects people across all body sizes, and insulin resistance can occur in people who aren’t overweight.

Fatigue and sleep problems

Significant tiredness is common, although fatigue has many causes and shouldn’t automatically be blamed on hormones. Obstructive sleep apnoea is more common in PMOS, even after taking BMI into account. So if you snore, wake up unrefreshed or feel tired all day, it’s worth talking to a healthcare professional.

Mental health-related symptoms

PCOS isn’t only physical. Depression and anxiety are more common, and symptoms like acne, unwanted hair growth, fertility difficulties, body-image concerns and weight stigma can all affect quality of life. Current guidance recommends that psychological wellbeing forms part of PMOS care, including screening and support for depression, anxiety and eating disorders.

Difficulty conceiving

PCOS is a leading cause of irregular ovulation and anovulatory infertility. If ovulation happens less often, there are fewer chances for egg and sperm to meet. But that’s very different from saying everyone with PCOS is infertile; many conceive naturally, and effective treatments exist when ovulation needs support.

What causes PCOS?

There is no single known cause of PCOS. Instead, it appears to develop through a combination of genetics, hormone signalling, ovarian function, metabolism and environmental factors. Two factors that are particularly important are androgens and insulin.

High levels of Androgens

Androgens are a group of hormones, the most common being testosterone. They are produced mainly by the ovaries and adrenal glands and have roles in reproductive health, bone and muscle health, sexual function and wider physiology.

Many people with PCOS have higher androgen levels or increased androgen activity, known as hyperandrogenism. This can contribute to characteristic PCOS symptoms such as excess facial or body hair, acne and scalp hair thinning.

Higher androgen activity can also interfere with normal follicle development and ovulation.
The small follicles sometimes seen on an ultrasound in PCOS are therefore not typical ovarian cysts. They are follicles that have not progressed through the usual pattern of development and ovulation.

Read more about testosterone and what your levels mean.

High levels of insulin

Insulin is a hormone that helps move glucose from the bloodstream into cells, where it can be used for energy. With insulin resistance, cells become less responsive to insulin, so the body may compensate by producing more of it.

Higher insulin levels can interact with androgen production and reduce levels of sex hormone-binding globulin (SHBG), which regulates testosterone levels, potentially increasing the amount of testosterone.

Insulin resistance may also contribute to metabolic changes and increase the risk of conditions such as type 2 diabetes. It can affect many people, but not everybody with PCOS has insulin resistance, and it does not explain every aspect of the condition.

Is PCOS genetic?

PMOS runs strongly in families. Twin studies suggest genetics accounts for around 70–80% of your risk of developing it. If your mum or a sister has PMOS, you’re more likely to have it too. One study found PCOS in around 1 in 4 mothers and 1 in 3 sisters of people with the condition, compared to roughly 1 in 20 people overall

There isn’t a single “PMOS gene”, though. Large genetic studies have found that many different genetic variants are involved, each playing a small part alongside hormonal, metabolic and environmental factors. Recent research also suggests PCOS may be linked to changes in mitochondrial DNA – this is genetic material inside the cells which provide energy.

So while family history is one of the strongest clues we have, there’s currently no single genetic test that can diagnose PCOS on its own.

Does ethnicity affect PCOS?

PMOS prevalence, symptoms and the risk of metabolic complications can differ between populations. But differences shouldn’t automatically be assumed to be biological. Access to healthcare, inequalities in diagnosis and treatment, and wider social and environmental factors can all affect who is recognised, investigated and diagnosed.

How is PCOS diagnosed?

There’s no single blood test, scan or symptom that diagnoses PCOS. In adults, diagnosis is usually based on having at least 2 out of 3 recognised features, once other conditions that can cause similar symptoms have been ruled out.

1. Irregular or absent periods – suggesting ovulation isn’t happening consistently.
2. Clinical or biochemical hyperandrogenism – signs of higher androgen activity, whether visible (acne, hirsutism) or on blood tests.
3. Polycystic ovarian morphology – a higher number of small follicles and/or increased ovarian volume, now assessed in adults using either ultrasound or an AMH blood test.

Read our full guide to how PMOS is diagnosed in the UK.

Are there different “types” of PCOS?

You’ll often see PCOS described online as distinct types like insulin-resistant, adrenal, inflammatory or post-pill. It’s worth knowing these aren’t officially recognised medical subtypes and aren’t part of the diagnostic criteria. 

What they reflect is though is that PCOS has different main drivers in different people. For some, insulin resistance is central; for others, higher androgens or disrupted ovulation. That’s exactly why management works best when it’s tailored to what’s actually happening in your body, rather than a one-size-fits-all label.

Can you have PCOS with regular periods?

Regular periods make regular ovulation more likely, but don’t guarantee it, some people with apparently regular cycles still have ovulatory dysfunction, and you can also meet the criteria through hyperandrogenism plus polycystic ovarian morphology. If confirming whether you’re actually ovulating matters, appropriately timed progesterone testing can help.

Can the contraceptive pill mask PCOS?

It can make the signs harder to see. The combined pill regulates bleeding and alters androgen levels, so irregular cycles, acne or other androgen-related symptoms may improve while you’re on it, and reappear when you stop. It doesn’t cause PCOS; it can just hide an underlying pattern. Hormonal contraception can also affect how some hormone results are interpreted, so always tell whoever’s assessing you what you’re using or have recently stopped.

What hormone tests might be used when investigating PCOS?

There’s no single test for PCOS, so testing does two jobs at once: it helps confirm features of the condition, and it helps rule out other things that can mimic it. That second job matters more than people realise, because several conditions produce very similar symptoms.

Depending on your history and symptoms, hormone testing might include AMH, testosterone and SHBG (to assess androgen activity), other androgens such as DHEAS, LH and FSH (when looking into cycle and ovulation problems), prolactin (raised levels can disrupt periods) and thyroid hormones (thyroid conditions cause overlapping symptoms). 

That reliance on the bigger picture is also why ruling things out is so important. Irregular periods, androgen-related symptoms or changes in ovulation can all be caused by something other than PCOS including thyroid disorders, raised prolactin, non-classic congenital adrenal hyperplasia, hypothalamic dysfunction and primary ovarian insufficiency, with rarer causes considered where symptoms are severe or come on suddenly. Pregnancy, medication and hormonal contraception can all affect symptoms and blood results too, so they matter when interpreting what’s going on.

That’s why good PCOS diagnosis is about building the whole clinical picture, rather than simply checking one hormone and ticking a box.

When should you get checked for PCOS?

Having one possible PCOS symptom does not necessarily mean you have the condition.
However, it is worth speaking to a doctor if you have:

– persistently irregular periods
– no period for more than three months
– new or significant excess facial or body hair
– persistent acne alongside other hormonal symptoms
– scalp hair thinning
– difficulty conceiving
– symptoms that are affecting your everyday life or wellbeing.

Getting assessed is not simply about putting a label on your symptoms. It is about understanding why they are happening, ruling out other possible causes and identifying whether treatment or monitoring could help.

Can PCOS affect my fertility?

Yes, PCOS can affect fertility, mainly because it can interfere with regular ovulation. But having PCOS does not automatically mean you will have difficulty getting pregnant.

In a typical cycle, follicles develop until one becomes dominant and releases an egg. With PCOS, that process can be disrupted: several follicles may start developing without one consistently progressing to ovulation, so you might ovulate later, less often, unpredictably or not at all in some cycles. That also makes home ovulation tracking trickier, higher baseline LH, for instance, can make ovulation predictor kits harder to read and prone to false positives (our full guide on tracking ovulation with PMOS covers what actually works).

Some people with PCOS ovulate regularly and conceive without treatment; others need support to encourage ovulation. Reassuringly, ovulation-related infertility linked to PCOS has well-established treatment options.

Can you get pregnant with PCOS?

Absolutely, if you ovulate, pregnancy can happen naturally. Irregular ovulation may simply mean fewer chances to conceive in a given year, and a harder-to-predict fertile window. It’s also worth not assuming every fertility issue in someone with PCOS is caused by PCOS, age, sperm health, Fallopian tube and uterine health, endometriosis and other factors still matter and should be investigated where appropriate.

Read more: Trying to conceive with PCOS: what you need to know.

Can PCOS be cured?

There is currently no cure for PCOS, but its symptoms can be treated and managed. Treatment can also help reduce or monitor some of the longer-term health risks associated with the condition. Because PCOS affects everyone differently, management should usually be built around the symptoms and health goals that matter most to you.

How is PCOS treated?

There’s no single treatment. What’s right depends on your symptoms, wider health, whether you’re trying to conceive, and which parts affect you most, making periods more predictable for one person, acne or fertility for another. 

Depending on your needs, PCOS care may involve a GP, gynaecologist, endocrinologist, fertility specialist, dermatologist, dietitian or mental-health support.

Lifestyle and weight management

Lifestyle support is an important part of PMOS management. But that doesn’t mean everyone with PMOS needs to lose weight. PMOS affects people of all body sizes, and access to care should never depend on weight loss.

If you do want or need support with weight management, modest weight loss may improve some reproductive and metabolic outcomes. The 2023 international guideline notes that losing around 5–10% of body weight may improve symptoms and the chances of conceiving. The NHS describes possible benefits from losing around 5%. Current guidance also emphasises avoiding weight stigma and focusing on overall health rather than a number on the scales.

Healthy eating and regular movement

Weight loss is often the first advice people with PMOS are given, but it isn’t always easy. Restrictive dieting can harm your relationship with food, and disordered eating is more common with PMOS. That’s why a whole-person approach is important: a balanced diet and regular movement that you can keep up.

There’s no single diet proven to be best for PMOS. Despite the amount of nutrition advice online, you don’t need to cut out carbohydrates, gluten, dairy or fruit, and you don’t need to follow keto because you have PMOS. Current guidance recommends tailoring any changes to the individual rather than prescribing one diet for everyone.

For many people, a balanced eating pattern might include plenty of vegetables, fruit and other fibre-rich foods, wholegrains, good sources of protein and unsaturated fats. Choosing higher-fibre or lower-GI carbohydrate sources and pairing carbohydrates with protein, fibre or healthy fats can also help support blood-glucose regulation.

But the most important thing is finding an approach that works with your health, culture, budget, preferences and relationship with food and that you can realistically sustain.

The same applies to exercise. Walking, running, swimming, cycling, strength training, Pilates, yoga or a mixture can all support cardiovascular and metabolic health. There isn’t one specific form of exercise that has been shown to be universally best for PCOS.

Read our full guide to know more Is There a Best Diet for PMOS (PCOS)?.

Looking after your mental health

PCOS can take a real toll on emotional wellbeing. Living with unpredictable periods, acne, unwanted hair growth, weight concerns, fertility difficulties or a long diagnostic journey can all affect mental health.

Self-care strategies such as regular movement, sleep, journalling or relaxation techniques may be helpful for some people, but they are not a substitute for professional support when it is needed. If anxiety, low mood, body-image concerns or difficulties around food are persistent or affecting your everyday life, speak to your GP or another appropriate healthcare professional.

 At Hertility, you can also access counselling support alongside your reproductive-health care.

What medications can help PCOS?

For some people, lifestyle changes are enough; for others, medication helps. Common options include:

• Hormonal contraception, particularly the pill, if you’re not trying to conceive. It makes bleeding more predictable and helps manage androgen-related symptoms such as acne and excess hair. Avoiding very long gaps without a bleed also matters. If you ovulate very rarely, your womb lining can be exposed to oestrogen without the progesterone that normally follows ovulation. Over time, this can raise the risk of endometrial hyperplasia (a thickening of the womb lining) and, rarely, endometrial cancer, although the overall risk stays low.
• Dermatological treatments for acne, excess hair or hair thinning, including standard skin treatments, laser or light-based hair removal, or anti-androgen medication such as spironolactone in some cases. Anti-androgens need medical supervision and reliable contraception, as some can harm a pregnancy.
• Metformin, which improves the body’s response to insulin, used particularly where metabolic health is a concern, and which may help cycle regularity or ovulation for some, though not everyone with PMOS needs it.
• Ovulation-induction medication if you’re trying to conceive and irregular or absent ovulation is making it harder. Current guidance recommends letrozole as the first-line option, because it’s more effective than clomifene for many people. Clomifene (often known by the brand name Clomid), metformin, gonadotrophins or IVF may also be used, depending on your wider fertility picture.

Supplements

This is another area full of misinformation, and no supplement cures PMOS.

Inositol. The most-studied supplement is inositol, particularly myo-inositol. The review that informed the 2023 guideline found it may improve some metabolic measures, such as insulin resistance, but has limited clinical benefits for ovulation, excess hair growth and weight. If you already take metformin or another glucose-lowering medicine, talk to your GP or a Hertility clinician before starting inositol.

Vitamin D is also often discussed. If you’re deficient, correcting it matters for your general health. But taking it simply because you have PMOS hasn’t been shown to treat the condition.

Read our full guide: Best supplements for PMOS (PCOS): what actually has evidence?

If you are looking to connect with other people experiencing PCOS, you could also check out charities and support groups such as Verity and Cysters

What are the long-term health risks of PCOS?

PCOS is increasingly understood as a lifelong endocrine and metabolic condition, not just something that matters while you’re having periods or trying to conceive, though that doesn’t mean everyone will develop another condition.

PMOS has been associated with a higher risk of insulin resistance and type 2 diabetes, higher cholesterol and blood pressure, excess fat in the liver, cardiovascular disease, mental health conditions like depression and anxiety, obstructive sleep apnoea, endometrial (womb) cancer, and pregnancy-related complications such as gestational diabetes and pre-eclampsia. 

Knowing this isn’t cause for alarm, it’s the reason monitoring and prevention matter, and why PCOS is worth taking seriously as a whole-body condition across your life.

How can Hertility help with PCOS?

One of the challenges with PCOS is that no single test tells you everything. That’s why Hertility starts with the bigger picture.

Our Online Health Assessment asks about your symptoms, periods, lifestyle and health history and uses that information to personalise your next steps.

The Advanced Hormone and Fertility Test then analyses a personalised panel of hormones, which may include AMH, FSH, LH, oestradiol, prolactin, testosterone, DHEAS, SHBG and thyroid markers, interpreted alongside your cycle, symptoms and wider health, not in isolation. It comes with a doctor-written report and care plan plus a call with an expert, so you can talk through what your results mean and what to do next. And if you need ongoing support, Hertility provides access to reproductive-health clinicians across gynaecology, Women’s Health GP, fertility nutrition and counselling.

Frequently Asked Questions

Is PMOS the same as PCOS?

Yes. PMOS (polyendocrine metabolic ovarian syndrome) is the new name for the condition previously called polycystic ovary syndrome, or PCOS. The name officially changed internationally in May 2026.

What are the first signs of PCOS?

Common early signs include irregular or infrequent periods, acne, excess facial or body hair, and difficulty with weight or metabolic health. But symptoms vary widely, and having one symptom doesn’t mean you have PMOS.

Can AMH diagnose PCOS?

No. In adults, AMH can be used instead of an ultrasound to assess polycystic ovarian morphology, but it shouldn’t be used as a standalone test for PMOS.

How can I get pregnant with PCOS quickly?

There’s no guaranteed quick route, but acting early helps. If your periods are irregular, speak to your GP rather than waiting a year to see if you conceive. Medication such as letrozole is effective for many people who aren’t ovulating, and healthy lifestyle changes can help too. Read our guide to getting pregnant with PCOS.

Does PCOS go away after menopause?

Not exactly. Periods and ovulation eventually stop, and some reproductive or androgen-related symptoms may change as your hormone levels change with age. But PMOS is increasingly recognised as a long-term metabolic condition that extends beyond your reproductive years. Longer-term risks, such as type 2 diabetes and cardiovascular disease, don’t automatically disappear after menopause.

Resources:

• Teede HJ, Tay CT, Laven JJE, et al. Recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Human Reproduction. 2023;38(9):1655–1679. https://doi.org/10.1093/humrep/dead156
• World Health Organization. Polycystic ovary syndrome (fact sheet). https://www.who.int/news-room/fact-sheets/detail/polycystic-ovary-syndrome
• NHS. Polycystic ovary syndrome (PCOS). https://www.nhs.uk/conditions/polycystic-ovary-syndrome-pcos/
• Gibson-Helm M, Teede H, Dunaif A, Dokras A. Delayed diagnosis and a lack of information associated with dissatisfaction in women with polycystic ovary syndrome. Journal of Clinical Endocrinology & Metabolism. 2017;102(2):604–612. https://doi.org/10.1210/jc.2016-2963
• Vink JM, Sadrzadeh S, Lambalk CB, Boomsma DI. Heritability of polycystic ovary syndrome in a Dutch twin-family study. Journal of Clinical Endocrinology & Metabolism. 2006;91(6):2100–2104. https://doi.org/10.1210/jc.2005-1494
• Kahsar-Miller MD, Nixon C, Boots LR, Go RC, Azziz R. Prevalence of polycystic ovary syndrome (PCOS) in first-degree relatives of patients with PCOS. Fertility and Sterility. 2001;75(1):53–58. https://doi.org/10.1016/S0015-0282(00)01662-9
• Day F, Karaderi T, Jones MR, et al. Large-scale genome-wide meta-analysis of polycystic ovary syndrome suggests shared genetic architecture for different diagnosis criteria. PLoS Genetics. 2018;14(12):e1007813. https://doi.org/10.1371/journal.pgen.1007813
• NICE Clinical Knowledge Summaries. Polycystic ovary syndrome. https://cks.nice.org.uk/topics/polycystic-ovary-syndrome/
• NHS. Polycystic ovary syndrome: treatment. https://www.nhs.uk/conditions/polycystic-ovary-syndrome-pcos/treatment/
• Fitz V, Graca S, Mahalingaiah S, et al. Inositol for polycystic ovary syndrome: a systematic review and meta-analysis to inform the 2023 update of the international evidence-based PCOS guidelines. Journal of Clinical Endocrinology & Metabolism. 2024;109(6):1630–1655. https://pmc.ncbi.nlm.nih.gov/articles/PMC11099481/
• PMOS renaming announcement, May 2026. Add the official source.