Women looking in the mirror asking what the difference between PCOS and PCO is?

PCO vs PCOS: What's The Difference? A Comprehensive Guide

You’ve probably heard of PCO and PCOS, but do you know the difference? For many women, it’s a source of confusion. Many people think PCO and PCOS are the same, with the two terms often used interchangeably. But in fact, they are very different. 

It’s important to understand the difference between the two if you’ve been diagnosed with PCO or PCOS. 

In this article, we’ll make the difference between PCO vs PCOS crystal clear, giving you a comprehensive overview of both terms, who they affect, symptoms, causes and common treatments. 

PCO overview

PCO stands for polycystic ovaries and is characterised by a slightly enlarged ovary with twelve or more cysts on the surface. 

Polycystic ovaries contain a large number of follicles, which are underdeveloped sacs where the egg develops. In each monthly cycle, the ovary will release a mature egg from its follicles, but a small cyst can form when it doesn't open to release the egg. 

PCO is incredibly common, occurring in 20%-25% of women of childbearing age, and is a variant of normal ovaries. PCO is diagnosed via an ultrasound and, in most cases, won't cause symptoms, meaning that it's usually discovered accidentally during routine ultrasounds during pregnancy. 

Most cysts go away on their own within a few months without any treatment. However, if they increase in size, women can experience some uncomfortable symptoms such as bloating, menstrual symptoms or pelvic pain. 

PCOS overview

PCOS, or polycystic ovary syndrome, is a chronic hormonal condition which affects how ovaries work and causes women to have irregular periods. This imbalance is caused by the overproduction of the male hormone androgen. 

Androgen is naturally present in women in small amounts, but 60–80% of women with PCOS have hyperandrogenism — an excessive amount of the hormone. 

This results in numerous, small fluid-filled sacs, or cysts, that form in the ovaries, which can cause symptoms, including weight gain, acne, excessive hair growth, irregular periods, fertility problems, and fatigue (read our guide that discusses the link between PCOS and chronic fatigue to find out more). 

One of the most common causes of infertility, PCOS is thought to affect 1 in 10 women in the UK — including an estimated 8-13% of child-bearing women — and cannot be cured.

While PCO can be an element of PCOS, PCO alone doesn’t mean you have PCOS, and not all women with PCOS will have PCO. That’s because some women with PCOS will not have cysts. To be diagnosed with PCOS, you need to have at least two of the following symptoms: 

  • At least one polycystic ovary 
  • Menstrual cycles that are longer than 35 days or no periods at all
  • The overproduction of male sex hormones

To diagnose PCOS, doctors will give you blood tests looking for high levels of male hormones. You’ll also receive a pelvic examination and an ultrasound to check the size of the ovaries and whether or not they have cysts. 

Comparing PCO vs PCOS: differences and similarities

If you’re wondering what PCO and PCOS differences are, or whether PCO and PCOS are the same, here are key features, similarities and differences of each condition.



Who it affects 

20%-25% of women of childbearing age

1 in 10 women in the UK and an estimated 8-13% of child-bearing women

Type of disorder

Not a disease. It can be another variant of normal ovaries.

Metabolic disorder and hormonal condition


Typically no symptoms

Irregular periods, excessive hair growth, acne and weight gain


Usually harmless 

Issues with fertility and a higher risk of miscarriage. Health conditions like high blood pressure, heart problems, type 2 diabetes, obesity and uterine cancer

Genetic nature 

Can occur early in teenage years, during childbearing years or during and after menopause

Can appear in early teenage years and during child-bearing years (20s and 30s)


Various causes

Hormonal imbalance

Hormonal effects

Regular ovulation and undisturbed hormones

Higher levels of male hormones


Who it affects


Polycystic ovaries typically affect 20%-25% of women of childbearing age. They show up on ultrasounds but usually don’t present any symptoms. 


Polycystic ovary syndrome is one of the most common causes of infertility, but up to 70% of those affected are undiagnosed worldwide. PCOS affects 1 in 10 women in the UK and an estimated 8-13% of childbearing women. 

Type of disorder


PCO in itself is not a disease and is simply another variant of normal ovaries. While it can develop and lead to PCOS, this is not always the case, and it typically won’t affect fertility or increase the risk of a miscarriage.


Polycystic ovary syndrome is a metabolic disorder and hormonal condition that’s the result of unbalanced hormone levels and excess androgen. However, not all women with PCOS will have cysts on their ovaries. 



Women with PCO usually don’t experience any symptoms unless the cysts have grown in size. When this happens, symptoms can include menstrual problems, pelvic pain, frequently needing to urinate and bloating. 

These are not common and most women only discover that they have cysts on their ovaries by chance if they have an ultrasound scan. 


PCOS can cause some distressing symptoms, including irregular periods and a lack of ovulation, which can lead to fertility issues as well as excessive hair growth, acne and weight gain. As a result, some women will also experience mental health conditions such as anxiety and depression. 

Associated risks


Ovarian cysts are usually harmless and can even resolve on their own without treatment. However, some can grow too large, twist or rupture, which can cause severe pain or can develop into cancer, with a higher risk of ovarian cancer in postmenopausal women. 


PCOS can cause issues with fertility, making it more difficult for women to get pregnant. There is also a higher risk of miscarriage. 

Women who have polycystic ovary syndrome are also more likely to develop harmful health conditions like high blood pressure, heart problems, type 2 diabetes, obesity and even uterine cancer.

Genetic nature


Polycystic ovaries can occur early on in teenage years, during childbearing years or even during and after menopause. Most of the time, they are accidentally discovered during health checks in pregnant or older women.


Symptoms of PCOS can appear in early teenage years as well as later during childbearing years.



Functional cysts are the most common cause of ovarian cysts and can be triggered by your menstrual cycle. 

Each month, an egg forms inside the ovary in a follicle. When a follicle doesn’t release an egg or discharge the fluid inside that was protecting the egg as it grew, the follicle can swell and turn into a cyst.


Unfortunately, the exact cause of polycystic ovary syndrome is unknown, but it relates to a hormone imbalance. Many women with PCOS experience insulin resistance, resulting in higher insulin levels in the body, which may cause higher androgen levels. It is also more prevalent in those who are obese. 

PCOS is also thought to be genetic, meaning you’re more likely to have it if your mum or sister are also affected.

Hormonal effects


Women with polycystic ovaries usually don’t experience any negative hormonal effects and will experience regular ovulation and hormonal balance. 


PCOS is a hormonal condition, meaning that affected women have higher levels of male hormones, androgens.

Implications for fertility and miscarriage


Cysts on ovaries don’t usually cause fertility problems. PCO also doesn’t increase the chances of miscarriage unless a cyst ruptures during pregnancy and causes internal bleeding. 


While having PCOS doesn’t mean that you can’t get pregnant, it can be more challenging to conceive and is one of the most common causes of infertility. However, those with PCOS are at greater risk of miscarriage in the first trimester

PCO and PCOS treatments and prevention

PCOS supplements

Improved nutrition can really help some people with PCOS, which is where supplements come in. 

Research shows that women with PCOS are commonly deficient in magnesium, potassium and calcium, as well as vitamin B12, vitamin C and folic acid. Up to 85% of women with polycystic ovary syndrome also have low levels of Vitamin D, which also decreases insulin resistance prevalent in PCOS. 

Taking supplements full of these vitamins is a great way to treat, manage and improve PCOS symptoms naturally. 

Apple cider vinegar (ACV) 

Apple cider vinegar is great for improving insulin sensitivity in those who are resistant or diabetic. It may also reduce blood pressure, regulate periods and improve ovulation.

Take 2 Novomins Apple Cider Vinegar Gummies a day for the best results. To find out more about ACV, take a look at our guide "6 Apple Cider Vinegar Benefits: What's All The Fuss?". 

Lifestyle changes

Aside from medication and supplements, various lifestyle changes can also improve PCOS symptoms, helping you regain control. 

Changes you can implement into your daily life include moderate exercise, like yoga or pilates, and reducing sugars and carbohydrates in your diet to manage your weight and keep blood sugar levels in check. Losing even 5% of weight can significantly improve symptoms.

Dietary changes

Eating a balanced diet high in fibre, whole grains, fatty acids, and anti-inflammatory foods helps women manage PCOS by combating insulin resistance. 

Whole grains are high in fibre, meaning they won’t spike blood sugar levels like regular carbohydrates. Research also shows that those with PCOS display higher levels of inflammation, which can lead to other illnesses like heart disease. 

Opting for low-inflammatory foods, like those found in Mediterranean diets, helps eliminate refined sugar and saturated fats, which is a great way to reduce inflammation.


Clomifene is a common PCOS medication that encourages ovulation and is recommended as a treatment for women who are trying to get pregnant. 

Metformin is another medicine that’s recommended to promote ovulation and is also used to treat diabetes, lowering blood sugar levels. 

Other common medications include the contraceptive pill and progestogen tablets to regulate menstruation. 

Bottle of Novomins ACV Gummies. Infused with Vitamins B6, B12 & D2

Improve your PCO and PCOS symptoms with Novomins

Despite both PCO and PCOS affecting a high percentage of women in the UK and around the world, the terms are often misunderstood and confused with each other. 

PCO (polycystic ovaries) refers to a cluster of twelve or more cysts on one or both ovaries. PCOS (polycystic ovary syndrome) is a complex metabolic disorder and hormonal condition characterised by the overproduction of male hormones and insulin resistance. 

While some women with PCOS will also have PCO, this isn’t always the case. 

If you’re displaying symptoms of PCOS — which include period irregularities, excessive hair growth, acne and weight gain — or have already been diagnosed with either PCO or PCOS and are concerned, don’t hesitate to reach out to your local GP and seek medical advice.

Along with medication, lifestyle changes, like regular exercise and taking supplements like Novomins PCOS and Apple Cider Vinegar Gummies, can also play a big part in managing and improving symptoms and your overall health. 

Our delicious gummies are specially formulated using high-quality, non-GMO ingredients by our team of doctors, nutritionists and scientists. We’re committed to providing effective vitamins that work and are designed for the needs of women’s bodies that are so often misunderstood. 


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