PMOS

Polyendocrine metabolic ovarian syndrome, or PMOS, is a common hormonal disorder that affects women. It happens when a woman’s ovaries begin to develop fluid-filled sacs called follicles.

It causes a range of symptoms that affect everyone differently.

Some transgender men also have PMOS. If you have PMOS and want to understand the condition better or explore treatment options, you should talk to your doctor.  

What causes PMOS?

It’s not clear what the underlying cause of PCOS is, but we know it’s related to abnormal hormone levels in the body.

Many women with PMOS have insulin resistance. This is when the cells in your body do not absorb insulin from your blood properly.¹

This can make your body produce more male hormones or androgens. It can also increase the levels of testosterone that are active in your bloodstream.

There are other hormonal imbalances that are common in women with PMOS, like higher levels of serum luteinising hormone and serum oestrogen.² This is what causes most of the symptoms of PMOS.

Our genetics may also play a role, and some people may have PMOS because it runs in families. However, it can’t be tested for because the genes that trigger it haven’t been identified yet.³

What are the symptoms of PMOS?

There are a range of symptoms associated with PMOS. Some of the most common are:

You must experience at least two of these symptoms to be diagnosed with PMOS.

High levels of androgens can also cause some of the symptoms that people with PMOS experience. These include:

PMOS can increase the risk factors of developing many other conditions. Not everyone with PMOS will develop these conditions.

Because of the insulin resistance common in women with PMOS, some are at risk of developing type 2 diabetes. One study of women with PMOS found that 19% of them developed type 2 diabetes, while only 1% of women without PCOS went on to experience type 2 diabetes.⁶

Research has found that women with PCOS are at a higher risk of cardiovascular disease, which may be linked to insulin resistance and hormonal imbalances common in PMOS. Some other conditions related to PMOS include sleep apnoea (abnormal breathing during sleep) and mental health issues like depression and anxiety.¹

Women with PMOS are also three times more likely than the general population to develop endometrial cancer, but the risk is still relatively low.¹ If you have PCOS, make sure to get regular screenings at your doctor’s recommendation and report any new symptoms.

Does PMOS affect fertility?

Because PMOS can stop ovulation, some women with PMOS may struggle to get pregnant.⁴ This doesn’t mean you can’t conceive, but you may need fertility treatment.

One medication often prescribed to women with PMOS who are trying to get pregnant is clomifene. It works by helping your body to ovulate. There are other medications like metformin and letrozole which are not licensed for helping fertility in PMOS, but they are sometimes used ‘off-label’ if clomifene does not work for you.⁷

Can PMOS affect your weight?

Women with PMOS are more likely to be overweight or obese than average. This is often caused by insulin resistance and hormonal imbalances that often appear in PMOS. Being overweight can also often make PMOS symptoms worse.⁸

If you’re struggling to lose weight, your GP may be able to refer you to a dietician, which is a specialist who focuses on eating behaviour.

PMOS can’t be cured, but there are treatments to manage many of the different symptoms.

If you’re struggling with heavy, painful or irregular periods, hormonal contraception like the combined pill may help. This can also help with symptoms like acne or excess hair growth.⁸

There are other hormonal contraception options, like medroxyprogesterone and some types of IUS.⁸

If you have complications related to PCOS, like diabetes or sleep apnoea, you may be referred to a specialist.

All medications come with a risk of side effects. Often these side effects are temporary and happen while your body adjusts to the medication. Some side effects of the combined pill include nausea, headaches and tender breasts.⁹

If you don’t want to take the medication you’re prescribed for PMOS anymore because of side effects, talk to your doctor. They may be able to recommend another treatment that suits you better.

For some women, lifestyle changes can help reduce symptoms of PMOS. If you’re overweight, losing weight can improve your PMOS as well as your overall health. We have more advice about getting to a healthy weight on our website.

Being active can also help reduce your chance of complications from PMOS.¹⁰ So finding a type of exercise you enjoy and doing it regularly can reduce your risks for the future. If PMOS is affecting your mental health, it may help to talk to a counsellor. These are specialists who are trained to listen.