Perimenopause and sleep: Why your hormones are keeping you awake

Do you find yourself waking at 3am and struggling to get back to sleep? Are you getting enough sleep but still feeling exhausted in the morning?

If you’re female and in your 40s or 50s, you may be able to relate to this - and it’s likely that your hormones have a lot to do with it.

Read on to find out how oestrogen, progesterone and cortisol affect sleep in midlife - and what actually helps.

Why sleep patterns change in your 40s

I wouldn’t say I’ve ever been an amazing sleeper. In my mid-30s and early-40s, I would often have trouble falling asleep, but once I finally nodded off, I would generally stay asleep until morning (unless I was woken by one of the kids or dogs - which happened on a regular basis…). Fast forward to my mid-40s and I no longer had as many problems falling asleep but I found myself waking in the early hours of the morning and lying there with random thoughts racing through my mind, sometimes for an hour or two.

It turns out that I’m not alone. Sleep changes in midlife are incredibly common, thanks to our hormone levels fluctuating during perimenopause and menopause. Oestrogen supports the production of serotonin and melatonin, both of which are essential for good sleep. Progesterone has a natural calming effect on the brain. When both of these hormones start to decline, the impact on sleep quality can be significant, leaving many women sleeping more lightly, waking more often, or feeling unrefreshed even after seven or eight hours’ sleep.

The role of progesterone in sleep quality

Progesterone is our natural sleep hormone, thanks to its calming, sedative effect and the fact that it activates GABA receptor sites in your brain, allowing your mind and body to relax. If you fall into bed each night completely exhausted, but then lie there feeling wired and unable to relax, this is commonly an indicator of low progesterone.

For some women this is a permanent shift - post-menopause, progesterone is consistently low and sleep difficulties tend to be ongoing. For others, particularly in perimenopause, it is more cyclical. Progesterone rises after ovulation and drops again before your period, which is why many women notice their sleep is noticeably worse in the week or so before their period arrives.

How oestrogen affects deep sleep and night waking

Oestrogen affects how deeply you sleep, due to its role in supporting serotonin and melatonin production. In perimenopause, oestrogen fluctuations can make sleep feel unpredictable and frustrating, varying significantly across your cycle and from month to month. After menopause, oestrogen settles at a lower level which, for many women, means sleep becomes lighter and less refreshing overall.

Falling oestrogen levels are also the main driver behind hot flushes and night sweats, which for many women are the most disruptive sleep factor of all. Waking drenched and overheated in the middle of the night makes it very hard to get back to sleep, and ongoing broken sleep can accumulate quickly into significant fatigue.

Why you wake at 3am and what cortisol has to do with it

It would be remiss of me not to mention the impact of stress and cortisol on sleep, particularly when it comes to busy midlife women. 

When we are under chronic stress, cortisol levels can remain elevated into the evening rather than following their natural downward curve. This disrupts blood sugar regulation overnight, and when levels drop too low the body triggers a stress response to correct it - releasing adrenaline and cortisol to bring the blood sugar levels back up. For many women this happens somewhere between 2 and 4am, and once that adrenaline kicks in, getting back to sleep can feel almost impossible. Sound familiar? 

What actually helps

As midlife women, it can sometimes feel as though we are completely at the mercy of our hormones, but there are things we can do to improve our sleep.

Here are a few suggestions:

• Make sure dinner contains 25-30g of protein and a serve of healthy fats.

  This helps to stabilise blood sugar overnight and reduces the likelihood of that early morning wake-up.

• Consider magnesium supplementation to support cortisol regulation and improve sleep quality.

  Magnesium glycinate is particularly helpful as glycine has a natural calming and sedative effect and helps to lower core body temperature

• Reduce caffeine intake after midday.

  Caffeine has a half-life of around five to six hours, so an afternoon coffee can still be affecting your ability to fall and stay asleep well into the evening.

• Practice good sleep hygiene.

  Try to have consistent sleep and wake times, avoid heavy meals late at night and stay away from your phone at bedtime!

If poor sleep is significantly affecting your quality of life, I recommend speaking to a menopause-trained doctor about bioidentical hormone therapy, particularly if nutritional and lifestyle support alone are not providing enough relief. For many women, hormone therapy can make a big difference to sleep quality and overall wellbeing.

References

Polo-Kantola, P. (2011), ‘Sleep problems in midlife and beyond’, Maturitas, vol 68 no. 3, 224-232.

Pelz, M. (2023), The Menopause Reset, Hay House, California.

Newson, L. (2023), The Definitive Guide to the Perimenopause & Menopause, Yellow Kite, London.