Four likely causes of your PCOS fatigue

By Clare Goodwin

Last updated: September 3, 2020

A few weeks ago I published a case study of one of the women that was in my protocol group, Tracy. She was crippled by PCOS fatigue and apart from weight gain, fatigue was her chief complaint.

As Tracy said:

“I was exhausted all the time and took long naps after working out. This was just my norm but something seemed off.  I was barely surviving the day.

At my yearly visits, I kept telling the endo how tired I felt all the time. He kept telling me that was just PCOS. I felt frustrated after every appointment because I knew deep down this wasn’t right but an authority figure was telling me otherwise. He just kept pushing the low calorie diet, exercise and Metformin (which I couldn’t tolerate and didn’t want).”

This case study got an overwhelming response in my Facebook group and upon surveying them, I found that so many of them, like Tracy, were also suffering from PCOS fatigue.

But the good news is, you don’t have to live with this fatigue.  Like Tracy (and also my own personal experience), this can improve, it’s all about fixing the root cause of this fatigue.

“No longer do I have a constant worry about being a sideline mom. I can play with my child and still have energy to stay up with my husband even after a full day of teaching.”

Why is fatigue in PCOS so common?

With so many women with PCOS suffering from this fatigue, you might think that it’s something about the hormonal imbalance or the ovarian ‘cysts’ that causes the fatigue.  But actually it’s likely to be the other way around:  the mechanism that’s causing the fatigue i.e. high stress hormones, blood sugar rollercoaster and vitamin and mineral deficiencies, is likely also causing the hormonal imbalance.  The good news here is that if we treat the underlying issue we fix both.  Two birds, one stone. Boom.

What can cause fatigue in PCOS?

PCOS fatigue can be caused by many things, but I’ve picked out the most common ones that I see in my patients.  You don’t have to fit any of them, or you could fit all of them!

‘Adrenal fatigue’

‘Adrenal fatigue’ (or more accurately HPA- Axis dysfunction), is the most common cause of PCOS fatigue that I see.  Adrenal fatigue is very simply when you’ve been so stressed for a long time, that your stress response just doesn’t work properly anymore. This stress can come from psychological stress like running late for meetings, being slammed at work, health or financial crisis in the family etc.  Or is can be due to physical reasons like chronic over exercising, lack of sleep and often eating too little.

The pattern I see very often in my patients, is a combination of all of these:  high pressure job, working late nights, but then still getting up to do 2 gym sessions to try and control  weight and then trying to combat the tiredness with caffeine which just stimulates the stress hormones even more. After weeks or months of pumping out the stress hormones their bodies no longer able to adapt to the stress and the fatigue rapidly sets in.

When we are under chronic stress our adrenal glands pump out cortisol as well as a hormone called DHEA-S.  DHEA-S is like a brother from a another mother to testosterone- it causes the male hair growth, acne, irregular periods etc and also gets converted into testosterone.  Up to 30% of those of us with PCOS have high DHEA-S, so this is what I mean by the root cause of the hormone imbalance, also causing the fatigue.

The blood sugar rollercoaster

This also is linked to your stress hormones.  One of the functions of your stress hormone cortisol is to help release stored blood sugar. We store glucose as glycogen in the liver, and when our blood sugar drops, cortisol is released to help release that glycogen as glucose to bring blood sugar back up to normal. But if you have inadequate cortisol, when your blood sugar drops, your body doesn’t release glucose the way a normal person would, and then you are going to feel hangry, shaky and jittery and often then very fatigued.  If this is the case for you, it’s very likely that you’ve got some early stage insulin resistance going on.  And given that up to 70-80% of women with PCOS have some insulin resistance, this is very likely.

You’re lacking some essential vitamins and minerals

Vitamins and minerals are essential for all reactions in our body, including the stress response and energy.  For example, iron is what transports oxygen around our body, so if we do not have enough iron, we simply can’t get enough air which can make us feel very tired. Given that 11% of women in the western world have iron deficiency, it’s worth getting your levels checked.

Although I would say that if you have insulin resistance, you’re actually likely to have too much iron – so get your Ferritin levels checked rather than just blindly supplementing,

The B Vitamins are also critical for your body to make energy.  If you don’t have enough B vitamins, then this energy production just won’t occur- you can think of this like a car factory.  If the factory normally produces 100 cars an hour, but you only have 50 sets of tires, then it will only be able to produce 50 cars. Similarly, if your body only has 50% of the B- vitamins it needs, it’ll only produce 50% of the energy it normally would.

Metformin depletes the body of vitamin B12, and 30% of people who take Metformin are vitamin B12 deficient.  So if you take, or have taken Metformin, get your B12 tested.


Up to 25% of women with PCOS have hypothyroidism or an underachieve thyroid.  Our thyroid is our chief controller of metabolism, so when it’s under active, we’ll not only be burning less energy, but also feel excessively tired and also find that we’re quite brain foggy too.

What’s a ‘normal’ level of fatigue

I get asked every week, “How do you know when fatigue is normal?  I have other friends who don’t have PCOS that also feel really tired when they wake up in the morning, so isn’t this just normal”

Frankly no, what we’ve done here is confused what’s normal with what’s common. For example, cancer and Type 2 diabetes have become very ‘common’ in our society, but they are not ‘normal’.

I would say that it’s normal to feel tired at night after a days work, but then be able to get into bed and fall asleep within a few minutes of trying.  What’s not normal is to lie there tired and wired, and/ or wake up feeling like you’ve been hit by a bus even after 7-8 hours of sleep.

Symptoms of ‘Adrenal fatigue’

  • Cannot stay asleep
  • You feel excessively tired after exercise for longer than 20 minutes
  • Wake up tired even after 7- 8 hours sleep
  • Afternoon fatigue
  • Afternoon headaches, or headaches with exertion or stress
  • Unable to get to sleep ‘tired but wired’
  • Sweat easily – with little or no exertion
  • Crave salt

How to get more energy with PCOS

Firstly read the articles on thyroid, and insulin resistance and get your iron and vitamin B12 tested.  Then follow these steps to address your stress hormones:

Reduce stress

This is the first and foremost thing you need to do.  Take stock of everything that’s causing you stress and think about how you can eliminate it i.e. handing off projects that are outside your scope of work, removing yourself from people that make you stressed, taking some evenings and weekends off to use relax rather than running around catching up with everyone.

For stress that is out of your control, think about how you could reframe that stress so that your body actually doesn’t perceive it as a stressor i.e. viewing a redundancy as an opportunity for a new path, rather than a threat to your self worth.

Get more sleep

When you get less than 5 hours sleep a night you not only feel crappy, but your body also produces more cortisol as well. The ‘standard’ 7-8 hours is good, and definitely much better than 5, but while you’re trying to repair your stress response, you might find that your body just needs more sleep, for example, I needed 9- 9.5 hours when recovering from my PCOS fatigue (or adrenal fatigue).  So go to bed early enough to give yourself enough time to wake up naturally and then you’ll figure out how much sleep you actually need right now.

Take a break from the hard core HIIT or endurance exercise for a while

While exercise is great, if your stress hormones aren’t working properly then the intensity HIIT exercise, or even  running can be too much for those fragile adrenals.  When you do this kind of exercise, it not only produces stress hormone during exercise but up to 48 hours after exercise.

So my recommendation is to drop this back to lots of walking and standing, and strength training- but focus on lifting heavier, rather than getting your heart rate up.  This doesn’t have to be forever, you can get back to this when your stress response has improved.  For me this took about 6 months, but some people can be longer or shorter.

Cut the caffeine

Caffeine is a stimulant that stimulates your adrenals to produce more stress hormone.  While you might feel that you simply cannot function without coffee in the morning, this is actually just stimulating your adrenal glands to produce more stress hormone so you’re just exacerbating the PCOS fatigue. Going cold turkey on the caffeine is likely going to result in some horrific headaches, so instead, I recommend cutting your caffeine intake in half every 4 days to titrate yourself off.