Polyendocrine metabolic ovarian syndrome, often shortened to PMOS, is a very common hormone and metabolic condition. It was previously called polycystic ovary syndrome, or PCOS. The updated name is helpful because it better reflects what the condition actually involves. PMOS is not just about the ovaries. It can also involve hormones, insulin levels, metabolism, body weight, skin, hair growth, periods and fertility. Although PMOS can be frustrating and upsetting, the good news is that it can be managed with the right support, regular health checks and treatment when needed.

What is Polyendocrine Metabolic Ovarian Syndrome?

PMOS is a hormone and metabolic condition that can affect how the ovaries work. People with PMOS may have irregular periods, higher levels of hormones called androgens, such as testosterone, and sometimes ovaries that look polycystic on an ultrasound scan. This means the ovaries may contain many small follicles. These follicles are common in PMOS and are not the same as harmful cysts.

PMOS can affect people in different ways. Some people have only mild symptoms, while others have symptoms that affect their confidence, wellbeing or plans for pregnancy. Having PMOS does not mean you will definitely have all the symptoms, and it does not mean you cannot have children.

Why has the name changed from PCOS to PMOS?

The older name, polycystic ovary syndrome, focused mainly on the appearance of the ovaries. This could be confusing because the small follicles seen on an ultrasound are not dangerous cysts, and not everyone with the condition has polycystic-looking ovaries. The term PMOS gives a broader and more accurate description. It recognises that the condition can involve endocrine hormones, metabolic health and ovarian function.

What causes PMOS?

We do not know the exact cause of Polyendocrine Metabolic Ovarian Syndrome, but it often runs in families. Many people with PMOS also have higher levels of insulin. Insulin is a hormone that helps the body control blood sugar levels. When the body does not respond to insulin as well as it should, insulin levels can rise. This can lead to higher testosterone levels, which may cause symptoms such as irregular periods, acne and extra hair growth.

How is PMOS diagnosed?

There is no single test for PMOS. Your doctor will usually ask about your periods, skin changes, hair growth, weight history and any difficulties with fertility. They may also arrange blood tests to check hormone levels and sometimes an ultrasound scan of the ovaries.

PMOS is usually diagnosed when at least two key features are present. These include irregular or absent periods, signs of higher testosterone such as acne or extra hair growth, raised testosterone on a blood test, or polycystic-looking ovaries on an ultrasound scan. Your doctor may also check for other conditions that can cause similar symptoms.

What symptoms can Polyendocrine Metabolic Ovarian Syndrome cause?

PMOS can cause irregular periods or no periods at all. Some women develop acne or oily skin, while others notice extra hair growth on the face, chest, tummy or back. Some women experience thinning hair on the scalp. PMOS can also make it easier to gain weight or harder to lose weight, although people of any body size can have PMOS.

PMOS can also affect fertility because ovulation may not happen regularly. Ovulation is when an egg is released from the ovary. If ovulation is irregular, it may take longer to become pregnant. However, many people with PMOS do become pregnant, either naturally or with treatment.

Why does PMOS matter for long-term health?

PMOS does not usually shorten life but it can increase the risk of some longer-term health problems. This is why regular health checks are important.

Women with PMOS have a higher risk of developing type 2 diabetes, so blood sugar checks are important. Blood pressure and cholesterol may also be higher in some people with PMOS, especially if they are above their healthiest weight. Looking after these areas can reduce future health risks.

Periods are also important. If you have fewer than three or four periods a year, the lining of the womb can build up. Your doctor may recommend treatment to protect the womb lining and keep it healthy.

PMOS can also affect emotional wellbeing. Anxiety, low mood, poor body confidence and distress about symptoms are common. These symptoms are real and important. Please tell your doctor or clinical team if PMOS is affecting your mood, confidence or quality of life.

What can I do to help manage Polyendocrine Metabolic Ovarian Syndrome?

Lifestyle changes are one of the most important parts of managing PMOS. This does not mean aiming for perfection or following a very strict diet. Small, realistic changes can improve symptoms, support hormone balance and reduce future health risks.

Eating regular meals can help. A helpful pattern includes plenty of vegetables, fruit, high-fibre foods and protein. Slower-release carbohydrates, such as oats, wholegrain bread, brown rice, lentils and beans, may help support steadier blood sugar and insulin levels. It can also help to reduce sugary drinks, sweets, ultra-processed snacks and excess alcohol.

Movement is also useful. Regular activity such as brisk walking, swimming or cycling can improve fitness and help the body use insulin better. Strength exercises are especially helpful because building muscle improves how the body handles insulin. This does not have to mean going to a gym. Simple home-based exercises can still make a difference.

If you are above your healthiest weight, losing around 5-10% of body weight can improve periods, skin symptoms, fertility and long-term health. This can be difficult, and support from your clinical team can help. Sleep, rest and stress management also matter, because stress and poor sleep can make symptoms feel harder to manage.

Are there medicines that can help PMOS?

Medicines can help, depending on your symptoms and whether you are trying to become pregnant. Your doctor will discuss the best option for you.

Metformin is sometimes used to help the body respond better to insulin. It may help periods and weight in some women. The combined contraceptive pill can help make periods more regular and may improve acne and extra hair growth. Anti-androgen medicines can reduce the effect of testosterone on the skin and hair, but they are not suitable in pregnancy, so reliable contraception is usually needed while taking them.

Treatment should be personalised. The right plan depends on your symptoms, your health risks, your preferences and your pregnancy plans.

When should I ask for help?

You should speak to your GP or specialist team if your periods are very infrequent, if acne or hair growth is affecting your confidence, if you are struggling with your weight, or if you are trying to become pregnant and your periods are irregular. You should also ask for help if PMOS is affecting your mood or quality of life.

PMOS is common, and you are not alone. With the right information, regular checks and treatment when needed, PMOS can be managed well.

Useful resources

The NHS website (www.nhs.uk/conditions/polycystic-ovary-syndrome-pcos/) has reliable information on PCOS, which is the previous name for PMOS.

Verity (www.verity-pcos.org.uk) is a UK charity that provides support for people living with PCOS/PMOS.

The askPCOS (www.askpmos.org) also has patient-friendly information and tools.