What Happens To Oestrogen In Perimenopause

Are you wondering exactly what happens with oestrogen in perimenopause? There can be a bit of confusion around this. So in this blog, I will provide clarity!

Firstly, I want to say that there are oestrogen receptors on every cell in the body, which means oestrogen has far-reaching effects on almost ALL body systems. Such as the brain, heart, bones, muscle, metabolism, skin, and even the gut and digestive system. All body systems feel the effects of oestrogen’s erratic behaviour in perimenopause and it’s eventual decline and loss at menopause.

‘Perimenopause’ refers to the natural phase of womanhood, beginning from mid to late 30s, where oestrogen is starting to shift and change and progesterone is declining. These hormonal shifts mark the bodies slow and gradual transition towards eventually going 12 consecutive months without a period, aka menopause. Therefore, perimenopause is a lengthy phase of anywhere from 5 to 15 years. It is NOT menopause. It is everything BEFORE menopause.

Common symptoms and changes to experience throughout the various phases of perimenopause (which I’ll recap below) are:

  • Changes to your sleep – Waking up in the night, trouble falling back to sleep, trouble getting to sleep
  • Changes to your mood – Irritability, anxiety, low mood, anger, rage, mood up and down. More so around PMS time
  • Changes to your cycle – Heavier periods (including clotting), painful periods, longer periods, shorter cycles, irregular cycles
  • Physical changes – Weight gain, increased belly fat, painful and or swollen breasts, low libido, vaginal dryness
  • New allergy symptoms – (Symptoms related to histamine) New allergies to foods, smells, chemicals etc., skin rashes or hives, hayfever-like symptoms
  • Vasomotor symptoms – (Symptoms related to temperature control) Hot flushes, night sweats

The symptoms and changes are related to a blend of declining progesterone levels and the rollercoaster of oestrogen. The symptoms usually evolve over time, being more and less prominent throughout the various phases of perimenopause.

Before we take a closer look at exactly what’s happening with oestrogen in perimenopause, let’s recap the phases of perimenopause (as also detailed in my ‘Perimenopause 101’ blog post).


1) Very Early Perimenopause: 38 – Early 40s

Symptoms are largely related to losing progesterone. You may experience subtle changes related to nervous system and mood, such as:

  • Very mild changes in mood
  • Very subtle changes in things like confidence, sociability, outgoing nature etc.
  • Fleeting anxiousness
  • Usually no change to menstrual cycles / periods are still regular

2) Early Perimenopause: Early – Mid 40s

Progesterone is dropping even more, while oestrogen remains high / becomes higher, you may experience:

  • Onset of irregular periods. Menstrual cycle can become shorter in length, by 2-5 days or more
  • Heavier periods, often with flooding or clotting

3) Mid To Late Perimenopause: Mid To Late 40s

Oestrogen is fluctuating more wildly, sometimes spiking up to 2-3 times higher than ever before. Resulting in neurological symptoms such as:

  • Hot flushes
  • Night sweats
  • Migraines
  • Brain fog and memory issues
  • Cycle length gets longer as ovulation occurs less and less. Missed periods and cycle lengths of 60 days plus

4) Late Perimenopause To approaching Final Menstruation: The Graduation To Menopause

Oestrogen is now consistently lower and the turbulent fluctuations are over. You are almost at the 12 month mark of no periods or you have already reached the 12 month mark and have officially graduated in post-menopause. This is the most stable hormonal phase of them all.

You can learn more about the phases and changes from Dr Jerilynn Prior’s amazing work in the stormy waters of perimenopause.


Perimenopause STARTS with HIGH and fluctuating oestrogen and ENDS with LOW levels (menopause).

As mentioned in the perimenopause phases above, as you move into your 40s, oestrogen is actually quite high and it doesn’t start to decline until late 40s, for most. In fact, from late 30s to mid 40s, it can rise to levels 2 or 3 times higher than you’ve ever had before.

Along with these higher levels of oestrogen, it is also erratically fluctuating like a rollercoaster. It’s fluctuations become more wild and erratic the further you move through your 40s.

So, all at once we start to experience symptoms of oestrogen being higher AND of it’s erratic swings. When oestrogen is high, it naturally places us in an “oestrogen dominant” or “unopposed oestrogen” state. This basically means having a higher oestrogen to progesterone ratio. Oestrogen and progesterone work TOGETHER as a team to maintain balance and calm. And so when oestrogen dominates over progesterone or is left unopposed by it, symptoms of oestrogen excess or unopposed oestrogen ensue.

Even if oestrogen levels are not elevated, unopposed oestrogen will still be the case due to declining/low levels of progesterone which is part of the entire perimenopause picture, even from late 30s.

Typical symptoms of unopposed oestrogen include:

  • Miserable periods (heavy, clotting, flooding, painful)
  • Breast pain and or swelling
  • Mood swings, rage, irritability
  • Water retention (‘puffy’)
  • Headaches
  • Growth of fibroids or cysts
  • Histamine or mast cell reactions

The Highs and Lows Of The Oestrogen Rollercoaster

The erratic highs and lows of oestrogen in perimenopause impact your nervous system and create a multitude of symptoms, all at once.

The highs of the rollercoaster can bring the symptoms of unopposed oestrogen mentioned above, whilst the lows of the rollercoaster can bring:

  • Hot flushes
  • Night sweats
  • Migraines
  • Brain fog, brain fatigue
  • Anxiety
  • Insomnia / sleep issues
  • Low mood / depression
  • Energy issues

Oestrogen Clearance Issues

Another important concept to understand is oestrogen metabolism. Also known as oestrogen detoxification, oestrogen metabolism refers to how we break down our used oestrogen (primarily occurring in the liver) and clear it out of the body. This process is essential for managing symptoms and for oestrogen health generally. When it comes to oestrogen, you need to use it and efficiently LOSE it!

With oestrogen being super high potentially until late 40s AND fluctuating so wildly, it’s ever more important for the body to be efficient at metabolising (breaking down) your used oestrogen and clearing it out. In a future blog I detail exactly how the body (liver and gut) does this. But for now, just know that this process is occurring 24/7, which means we ALWAYS want it to be working well otherwise we end up with a back up of old oestrogen remaining in the body (oestrogen excess). A back up of oestrogen leads to MORE symptoms of unopposed oestrogen that I’ve listed above. Excess oestrogen is also a risk factor for growth of fibroids, cysts and oestrogen driven cancers.

Factors that impact the efficiency of oestrogen metabolism include:

  • Deficiencies in cofactor nutrients for liver detoxification processes such as B-vitamins, magnesium, choline, DHA, EPA.
  • Alcohol consumption, because the liver puts breakdown of used oestrogen to back of the queue when any alcohol is present.
  • Compromised gut health or constipation (not passing a fully formed stool at least once a day), because broken down oestrogen goes to the gut to passed out of the body permanently in stool.
  • High intake of / exposure to oestrogen-mimicking chemicals (also known as xenoestrogens), such as those found in plastics, body, face, and hair care products, perfumes, household cleaning products, detergents, candles, plug-ins and air fresheners.


The good news is that some simple diet and lifestyle habits can support efficient oestrogen clearance as well as help to taper the highs and lows of the rollercoaster.

Here Are 5 Ways To Support Healthier Oestrogen Levels + A Calmer Rollercoaster!

1) Support Your Body To Ovulate As Many Months As Possible (To Make Progesterone)

It becomes harder to achieve ovulation as easily in your 40s compared to the previous decades. Therefore, it’s ever more important to support your body to ovulate in as many cycles as possible throughout this decade. Without intervening, your body will make less progesterone than it would had you taken steps to support and encourage ovulation. It IS possible to help your body to ovulate many more times (cycles) than it would have without your support. You can refer to my blog post here for more information on progesterone and ovulation.

2) Support Your Nervous System

Managing stress is more important in perimenopause than ever before. Your nervous system is impacted by stress and a dysregulated nervous system increases the likelihood and severity of many of the typical perimenopausal symptoms. Such as brain fog, hot flushes and night sweats, headaches and migraines, weight gain and belly fat, sleep issues, and mood issues.

Stress comes in many different forms and it’s important to consider them all when looking at your own unique situation. For example, financial issues, exercise, bereavements, divorce or separation, moving homes, job or career problems, relationship issues, children and other dependants such as ageing parents, past and present big and small traumas, blood sugar dysregulation, and even exercise are all stressors – just to name a few!

What are YOUR biggest stressors? How can they be managed better or even eliminated? Then, support your nervous system’s resilience and balance with good stress management habits each day. Such as walks in nature/green spaces, qigong, yoga, deep breathing exercises, and meditation. Even just 5-10 minutes a day of some of these things (scattered throughout the day) can make a profound difference. Having a healthy circadian rhythm also supports your nervous system. Read my blog post on “How To Sleep Well In Perimenopause” for more info.

3) Give Your Liver The Cofactor Nutrients To Work Efficiently

Certain foods, nutrients and botanicals can support the various detox phases and pathways in the liver. These include the B-vitamins folate, B12, and B6, magnesium, SAMe, betaine (also called Trimethylglycine or TMG), omega 3 fish oil (EPA and DHA), rosemary, and sulphoraphane (found in cruciferous vegetables).

4) Have Fully Formed Bowel Movements At Least Once Daily

In order to permanently remove used oestrogen from the body once it’s been processed by the liver, we must excrete from the bowel, AT LEAST once per day. Increase quality fibre from colourful vegetables, especially dark green leafy ones, and berries. This helps your friendly bacteria to flourish and thrive, adds bulk to your stool and regularity to your bowel movements. Keep your colon well hydrated with plenty of clean water and herbal teas throughout the day, and chew your food REALLY well!

5) Minimise Your Exposure To Oestrogen-Mimicking Chemicals

These are chemicals that ‘look like’ oestrogen and once inside the body, they can take the place of real oestrogen inside the cells. This causes havoc for the action, communication, and metabolism of your hormones as a whole. It also increases your total load of oestrogen, exacerbating all of the symptoms mentioned above with regard to unopposed or excess oestrogen. Simple ways to reduce your exposure/intake are to:

  • Use glass, ceramic or stainless steel for all cooking, heating, storing and drinking
  • Switch to cleaner skincare brands such as Green People, Antipodes, Sukin, Ren, Neal’s Yard and Tropic
  • Switch to cleaner household cleaning and detergent brands such as Bio-D, Method and Attitude
  • Avoid use of regular commercial candles, plug-ins and air fresheners
  • Avoid using perfume (I use Aesop perfume, which is chemical free)

I hope this post and information has been helpful for you as you navigate your way through your 40s. Even if you started with just ONE of the tips in this post you should notice some improvement. You don’t need to change everything overnight or start implementing 5 habits at once. Slow and steady always wins the race. So start with one thing and build from there over time. You are in this for a long haul!

Hi, I'm Francesca

I’m a Registered Nutritional Therapist who helps womens in their 40s find vibrant health and vitality, and thrive through perimenopause and beyond.

With nearly 10 years of experience working with hundreds of people, I empower and support women to support their bodies and hormones for a smooth and happy ride in their 4os.

Through our work together, clients have improved their energy, their periods and cycles, their mood, sleep, brain fog and digestion, and learned how to better manage their weight.

I am here to help you get back to YOU so you can have a fantastic time in your 40s.

My signature nutrition and lifestyle coaching approach to supporting women with their health and wellbeing is refreshing, down-to-earth and realistic.

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