Waking up tired, not getting started properly, a tummy that gets in the way, poor wound healing, difficulty concentrating or remembering things, a low libido, jittery feelings… These various symptoms can all be related to cortisol problems. And yes, it can even make it difficult to get pregnant. What is the relationship between our ‘stress hormone’ cortisol and infertility? I will go into this in more detail in this blog. First of all, it is good to tell more about the functions of cortisol.

What is Cortisol?

Cortisol is perhaps best known as our ‘stress hormone’. We produce cortisol when we are in danger. As humans, we have always faced threats. It can come from outside or be inside your body. For the latter, think of a pathogen, such as a bacteria or virus. Our body reacts very ingeniously to danger, namely with the well-known, classic fight-flight response. Two substances play a major role in this: (nor)adrenaline and cortisol. This stress system has ensured our survival throughout our evolution. How does the fight-flight response work?

The classic fight-flight response

Imagine being chased by a lion (that was not inconceivable when we once lived as hunter-gatherers in Africa). What is your body’s response? In short, (nor)adrenaline will quickly ensure that energy (glucose) goes to your muscles, heart and brain so that you become alert and can react quickly to save your body. This reaction goes through your nervous system and starts in seconds. The reaction with cortisol is slightly slower, because cortisol is ‘transported’ as a hormone through the bloodstream. First of all, cortisol also provides extra energy, or raises your blood sugar level.

It is of course quite possible that you will be injured while fleeing or fighting. During a stress reaction, the immune system is therefore activated to be able to be on the spot quickly. Adrenaline and cortisol together ensure that the immune cells go to the affected area.

Cortisol then also ensures that an immune response is switched off again, so that the immune system does not overreact. This is the anti-inflammatory effect of cortisol which is also used in certain medications.

Chronic Stress

And that is immediately the problem in our modern world. We have to deal with all kinds of factors that cause chronic, dormant stress, such as a sky-high mortgage debt, an annoying boss, unhealthy food with a lot of sugars, sleeping too few hours, worries about parents, (imagined) fears, etc. In short: chronic Stress can manifest itself in all sorts of ways. And the tricky part is that our bodies have no other way of responding to these chronic stressors than acute stress. So it reacts in the same ‘classic’ way as if that lion were standing in front of you. Only now the stress response is not terminated but remains dormant. And your immune system is not turned off by cortisol, in other words: the anti-inflammatory effect of cortisol is not working properly. This keeps the immune system slightly active, which is called low-grade inflammation.

What does this mean in practice?

Normally, cortisol functions in rhythm with a number of other important hormones: with melatonin, the thyroid hormone and our sex hormones. We explain it briefly here, because then you also understand why cortisol problems can lead to so many different complaints and symptoms – including infertility – as we described at the beginning of this blog.

Cortisol together with melatonin ensures our day-night rhythm

Cortisol is therefore not only our stress hormone, on the contrary: without cortisol we do not get out of bed in the morning. It is therefore better to describe cortisol as the hormone that ensures that we can be active during the day. Cortisol normally functions in a 24-hour rhythm with melatonin, our sleep hormone. These two hormones are opposites of each other and thus alternate. You wake up in the morning with a spike in cortisol production, called the cortisol wake-up response. Towards the evening, the production of cortisol decreases and the production of melatonin starts. And the next morning you wake up again because the cortisol production increases… etc.

Relationship with our thyroid and sex hormones

Cortisol not only functions in a rhythm with melatonin, but also with the thyroid hormone and the sex hormones, cortisol has a clear ‘relation’. In our brains are the two organs, the hypothalamus and the pituitary gland, which ensure that these three hormones alternate during a day. It is a bit simplistic, but with stress cortisol takes precedence and in rest and relaxed situations the thyroid hormone and the sex hormones. Your body obviously prefers to respond adequately to stress, because that has been essential for survival throughout our evolution. Then other important functions are discussed, such as repair and growth (thyroid hormone) and reproduction (sex hormones). Again, it’s a bit black and white, but in fact it comes down to this. And you may have guessed it: in our modern lives we suffer a lot from chronic stress factors, which give cortisol too much and too much priority over those two other important hormones.

And so, we finally come to the relationship between cortisol and pregnancy. With a lot of chronic stress, cortisol causes a hormonal imbalance, and melatonin, the thyroid hormone and our sex hormones are severely affected by this. Now you may have heard the example in your environment of a couple who wanted to get pregnant. So much so that it dominated their entire lives and that they did everything they could to have a baby. Fertility treatments, hormones, IVF… everything but nothing helped, until they decided to accept that they would remain childless. And then? Out of the blue, bingo! There is a good chance that the relaxation after the acceptance of the situation has helped them the most; cortisol was most likely able to function again in its normal rhythm with, among other things, the sex hormones.

Bottom Line: Cortisol is an extremely helpful hormone for us, in everyday life and in stressful situations, but as so often, it’s about balance. I therefore end this blog with some practical tips.

What can you do to bring cortisol back into balance with other hormones?

• An open door: ensure a good balance between tension and relaxation in your life.

• Visit nature every day. Take regular walks in the forest or on the beach. Especially barefoot.

• Make sure you do strength training a few times a week.

• Also think of acute stress stimuli that make your body stronger, more resilient, such as a cold shower or swimming in the sea or other open water.

• What gives you pleasure? Make a list and add it to your daily life.

• Think, for example, of yoga, mindfulness and meditation to relax mentally and physically.

• Get enough hours of sleep, but not too much (guideline: about 8 hours a night).

• Drink coffee in moderation.

• Think about what chronic stressors are in your life and deal with them. Chronic stress factors are, for example, a diet with a lot of sugars, carbohydrates and toxic substances, a lack of vitamins and minerals in your menu, little exercise, sitting a lot, lack of daylight and fresh air, a leaky gut and low-grade inflammation.

• Magnesium is an important mineral that can support you to relax and sleep well. Think of a (foot) bath with magnesium or a supplement.

• Other interesting supplements are vitamin D, the B vitamins and vitamin C.

• Adaptogen herbs can also help and support you. Think ashwagandha, rose root and L-theanine.


1. Segerstorm, S.C. et al., Psychological stress and the human immune system, a meta-analytic study of 30 years of inquiry, Psychological bulletin, 2004; 130

kPNI materiaal

L. Pruimboom, Word weer mens, uitgeverij Plumtree