Perimenopause and sleep: why your nights change in your 40s
If you slept well for most of your life and then started waking hot, wired or irritable in your early forties, the cause may sit in the years before your last period. This article explains perimenopause and sleep in plain terms: what happens to oestrogen and progesterone, why your temperature and mood change at night, the food, movement and evening habits I suggest, and when to see your GP.
Why sleep can change in your early forties
I slept brilliantly until I reached my early forties. Around 42 or 43 that changed. My temperature seemed to swing in the night, I woke feeling tired and irritable, my periods became heavier and I was quicker to anger than I had ever been. My first thought was that it could not be menopause, because I was still having periods.
That thought is common, and it comes from a mix-up in the words. Menopause is a single point in time: the day you have gone 12 months without a period, because the ovaries have stopped releasing eggs.
Perimenopause is the stretch of years leading up to it. For many women it begins in the early to mid forties, and it can last up to around ten years.
During perimenopause your periods usually carry on, but the hormones behind them stop following a steady pattern. Oestrogen and progesterone rise and fall unpredictably, and both have a big influence on your body temperature, your mood and your sleep. That is why the early signs tend to show up at night first.
If you want the background on the monthly rhythm that is changing, I explain it in the female hormonal cycle explained.
What happens to oestrogen and progesterone
Many people picture oestrogen falling gently year by year. In perimenopause the pattern is more erratic. Some months oestrogen is high, some months it drops sharply, and ovulation becomes less regular. Progesterone is made mainly after ovulation, so in months where ovulation is missed or weak, progesterone is low.
Those two hormones do different jobs in the brain, and each one affects sleep in its own way. I will take them one at a time.
Progesterone and the brain's calming signal
Progesterone breaks down in the body into a compound called allopregnanolone. It acts on receptors for GABA, short for gamma-aminobutyric acid, which is the main calming messenger in the brain. GABA helps quieten nerve activity, and that quietening is part of how you settle and stay asleep.
When progesterone dips, the calming signal it supports becomes weaker. Many women describe this as a feeling of being on edge, lighter sleep, or waking at some point in the night with a mind that has switched on. Research is still working out the details, and the picture varies from woman to woman. Some notice it most in the second half of the cycle, when progesterone would normally be at its peak. Others notice it only in the months when a period arrives late or heavy, which tells you the hormones were out of step that month.
This is also why I look at the nervous system early in any sleep problem. If you would like the wider view, my article on why you can't sleep and the three causes I look at first covers it.
Oestrogen and your internal thermostat
Your brain keeps your body temperature inside a range. When oestrogen is steady, that range is fairly wide. Small rises and falls in temperature pass without the brain doing anything about them.
When oestrogen starts to swing, that comfortable range narrows. The brain becomes far more sensitive, so a very small change in temperature is enough to set off a response. At night your body temperature naturally drops. A narrow range means the brain can read that normal dip as being too cold.
The brain's response is to widen the blood vessels near the skin so that warm blood moves from the core of the body to the surface. This is what produces a hot flush: the sudden rush of heat, the red face and neck, the sweat. Once you have sweated, the damp skin meets the cooler air in the bedroom and you feel chilled, so the duvet goes back on. Many women recognise the cycle of duvet on, duvet off, several times a night.
Each of those episodes can wake you, or lift you out of deep sleep into a lighter stage. You may not remember every waking, which is why some women feel unrefreshed in the morning without knowing why. Over a week that adds up to a lot of fragmented sleep.
Mood, anxiety and the sleep loop
Oestrogen also influences mood and how the brain handles anxiety. Most women have seen a version of this before a period, when tearfulness, irritability and a shorter temper are common. In perimenopause, the swings can be larger and less predictable.
Poor sleep then makes the mood changes harder to cope with, and a low mood or a racing mind makes it harder to sleep. Each one feeds the other, which is why I think it matters to work on the whole loop and not on one part of it. If your nights are already unsettled, the wind-down routine further down this page is a good place to start.
In my work with women in this stage of life, the first things I cover are the everyday habits below, because they are within your own hands and they cost nothing to try. Pick two or three and give them a fortnight before you judge them. Changing everything at once is hard to sustain, and it makes it impossible to see which change helped.
Food and drink that make evenings easier
Build meals from whole foods. Vegetables, pulses, eggs, fish, meat, nuts, seeds and whole grains give you steady energy and the nutrients your body needs for hormone production.
Cut back on refined carbohydrates and sugar. White bread, pastries, sweets and sugary drinks send blood sugar up quickly and down again, and the stress response that follows can add to night-time heat and waking. My article on eating regularly when life is busy covers how to keep energy steady across the day.
Keep alcohol low. Alcohol may help you drop off, but it makes sleep lighter in the second half of the night, and many women find it triggers hot flushes. Your liver also has to deal with it, and the liver is one of the organs that clears used hormones from the body, so a heavy evening drink adds to its workload at the time of day when you want everything to settle.
Eat protein at breakfast. A breakfast of eggs, yoghurt, nuts or fish gives your blood sugar a steadier start, and a steadier day tends to lead to a calmer evening.
Eat a lighter evening meal, and not too late. A meal built around protein and salad or vegetables suits most people better than a large plate of carbohydrate last thing at night. Finishing two to three hours before bed gives your digestion time to settle.
Look at your caffeine. Caffeine stimulates the stress response, and many women notice that coffee brings on a rush of heat. If you love coffee, a good-quality decaffeinated coffee is worth a try. I mean proper ground decaf, and many people cannot tell the difference. If you stop caffeine, reduce it over a week or two to avoid headaches.
Plant oestrogens
Some foods contain phytoestrogens, plant compounds with a structure similar to oestrogen. They act far more weakly than the hormone itself. The best-known source is soya in its whole forms: tofu, tempeh, miso, edamame, soya milk and soya yoghurt. Flaxseed, sesame seeds, chickpeas and lentils also contain them.
Research on phytoestrogens and hot flushes is mixed. Some studies find a modest effect and some find none, so I describe them as a food worth trying for a few months and not as a certainty. They suit many people well. Some people should check first. If you have had breast cancer, or another hormone-sensitive condition, speak to your GP or specialist before adding soya or phytoestrogen herbs to your diet. If breast cancer runs in your family, mention that to your GP as well.
Red clover is a traditional herb in this stage of life and is often taken as a tea. It contains similar plant compounds, so the same caution applies. Liquorice root tea is also traditionally used here. Liquorice can raise blood pressure when it is taken regularly in larger amounts, so check with your GP before using it if you have high blood pressure or take blood pressure or diuretic medication.
Movement
Keep moving through this stage of life. Regular exercise supports blood flow and circulation, and it also works on two things that change as oestrogen falls. The first is muscle: from midlife you gradually lose muscle unless you give it a reason to stay. The second is bone: oestrogen helps maintain bone density, and bone loss speeds up in the years around menopause. Weight-bearing exercise, such as brisk walking, resistance training and carrying a heavy shopping bag, gives bone a reason to stay strong. If weight gain is a concern, I look at that separately, because it deserves its own article.
Even ten minutes of movement after a meal helps blood sugar settle, and daylight in the morning helps set the body clock that governs sleep later. Gentler practices matter too. Yoga, Pilates, tai chi and qigong all build strength and flexibility, and they teach the nervous system to slow down, which is the state you want to be in when you get into bed.
An evening that sets up sleep
Keep the timing roughly the same each night, including weekends. Your body clock likes a pattern, and a regular bedtime does more than most supplements.
The hour before bed does a lot of work. These are the habits I suggest:
Put your phone away. Scrolling keeps the brain alert, and the light from the screen adds to it.
Run a warm bath. Your core temperature falls afterwards, which is a natural cue for sleep.
Drink something calm. A cup of chamomile, lemon balm or lime blossom tea works well.
Leave work and difficult conversations for the morning. Reading emails or a tense exchange late in the evening tells your nervous system that something needs handling now.
Cool the bedroom. A cooler room, a lighter duvet and layers you can take off easily suit a body that is sensitive to small temperature changes.
Herbs and tonics traditionally used at this stage
Herbal medicine has a long tradition of working with women through midlife, and several herbs are traditionally used to support this stage. Shatavari is an Ayurvedic herb used for women's health across the life stages, and research into it in this stage is still at an early stage. Chaste tree, also called Vitex, has long been used for women's cycle wellbeing. Holy basil and ashwagandha are adaptogens, herbs traditionally used to support the body's response to everyday stress. If you would like to know how adaptogens work, I explain it in what are adaptogens.
For nights, nervine herbs have a long history of use for relaxation and a settled evening, including passionflower, valerian, lemon balm, lime flower, hops and lavender.
I formulated two tonics around this tradition. Hormone Harmony combines ashwagandha, shatavari, chaste tree and holy basil, with three Australian Bush Flower Essences: She Oak, Mulla Mulla and Bush Fuchsia. Sleep Deep combines passionflower, valerian, lemon balm, lime flower, hops and lavender. They are paired in a duo: Hormone Harmony before food during the day, and Sleep Deep in the evening before bed.
A tonic is one ally alongside the habits above, and it works best taken consistently over weeks. The product pages carry the full safety information. Please read it, and if you take HRT, hormonal contraception or any other hormone-related medication, speak to your GP or practitioner before adding a hormone-focused herbal tonic.
HRT and other medical options
Herbs, food and lifestyle can sit alongside medical care, and I never suggest them as an alternative to it. Hormone replacement therapy (HRT) is an option many women find helpful, and your GP can talk you through the benefits and risks for your own health history. If you are weighing it up, a conversation with your GP is the right place to start, and what I describe in this article can be done at the same time.
When to see your GP
Perimenopause is a natural stage of life, and several things deserve a proper check:
your symptoms start before the age of 45
your periods become very heavy, you pass large clots, you bleed between periods or after sex, or you bleed more than 12 months after your last period
your sleep has been disturbed for longer than three months and it affects how you function
you snore loudly, or someone has seen you stop breathing or gasp in your sleep
your mood has become low or anxious most of the time, or you feel overwhelmed. If you feel unsafe, call NHS 111, or 999 in an emergency
you take prescribed medication, including sedatives, sleeping tablets, antidepressants or hormone-related medicines, and you are thinking of adding a herbal product
Where this fits
Perimenopause shows how closely sleep, hormones and the nervous system are linked. The two threads I come back to are the nervous system and blood sugar, and I explain why in hormone support: why I look at stress, blood sugar and the gut first. If you would like to see where your own starting point might be, the EarthWise health quiz is a good place to begin.
Sarah Burt is a registered naturopath, medical herbalist and iridologist with 25+ years of clinical experience. All EarthWise tonics are formulated by Sarah based on her clinical protocols.
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This article is for informational purposes only and is not intended to diagnose, treat or cure any health condition. Always consult a qualified health practitioner before making changes to your health regimen.
