PCOS has a huge impact on your periods – maybe not surprising given the condition has ‘ovaries’ in the title. Yet, so much of the information out there focuses on other side effects and management techniques, like insulin levels or hair problems. 

Perhaps that’s because of the period taboo that still exists or simply a lack of knowledge about how ovulation and menstruation are impacted by PCOS. Either way, it can feel scary and worrying when your period isn’t the same as the 28-day standard we are taught about in our Biology GCSE, so understanding how your condition impacts your flow is the first step to better managing your symptoms.

What can periods be like with PCOS?

One of the criteria for PCOS is irregular or missing periods. Because of the way the condition is characterised, not everyone will suffer from this disruption, but around 90% of women with the condition have cycles that last more than 35 days (the first day of your bleed is the first day of your cycle, so most women with PCOS have over 35 days between coming on their periods). 

A 2013 study into over 400 women with the condition suggests that around 40% of people with PCOS have cycles longer than three months. Another 27% had cycles that were between six and 12 weeks, and 10% had cycles that were 35 days to six weeks.

These long cycles are called oligomenorrhea. While cycle length can vary from month to month, to classify as having an irregular period you need eight or fewer bleeds per year, so if this sounds like you it’s important to discuss your symptoms with your doctor. 

PCOS causes these long and irregular cycles because of excess androgen hormones like testosterone, as well as excess luteinising hormone and low follicle stimulating hormones. This means that eggs often aren’t released from the ovaries, so the lining doesn’t shed for a regular period.

When an egg isn’t released, it also impacts your chances of fertility.

How heavy are periods with PCOS?

When people with PCOS do have periods, research suggests they are likely to suffer from heavy menstrual bleeding. A 2021 study published in the Healthcare journal found that around 56% of women with PCOS suffer from heavy bleeds. 

Researchers compared this to past research on people with periods but without PCOS: in Japan, only 19% of people suffered from heavy bleeds, while in Europe 27% did, showing that people with PCOS are more likely to suffer from menstrual dysfunction.

One reason for this could be because people with PCOS tend to have lower levels of progesterone, which is associated with heavier bleeds. It’s why many people are prescribed progesterone pills to deal with heavy period flows.

What do I do if my period is irregular?

You should always talk to your doctor if your period flow is irregular. Not only can it be a sign of PCOS, but it’s also a symptom of other conditions and may require urgent attention. 

Lifestyle interventions including exercise and nutrition are often the first port of call when dealing with PCOS. These are effective at reducing androgen hormones and, as such, may help regulate your bleeds. 

Supplements are also associated with improvements in menstrual regularity. A 2021 study, performed in 70 women with PCOS, found that Myo-inositol and d-chiro-inositol were effective in regularising menstrual cycles. It’s a small study, but over 80% of participants had a natural cycle while taking the supplements, and regular cycles resumed in over 27% of participants.

Whether your periods have stopped, are light, are heavy or arrive late every month, PCOS affects everyone differently. It’s important to speak to a professional if you are struggling with side effects of the condition.

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