Understanding What’s Happening with Oestrogen in Your 40s

Understanding What’s Happening with Oestrogen in Your 40s and oestrogen dominance

In perimenopause your hormones are behaving differently. In this blog post, I’m going to explain specifically what’s happening with oestrogen; what it’s doing in your 40s, the issues it brings and how you can support it.

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

It is a phase of biological rough waters but it CAN be navigated optimally with a smart captain at the helm of the ship (i.e. You!). Symptoms are temporary (thank goodness) and respond to simple diet and lifestyle habit interventions.


In your 40s, oestrogen 1) goes on a rollercoaster, sometimes spiking to levels 2-3 times higher than ever before, 2) starts to become the dominating hormone in the menstrual cycle, and 3) can be in excess – ALL at the SAME time.

Before we look at the 3 likely issues with oestrogen in your 40s, let’s see what oestrogen in balance looks and feels like. Oestrogen in balance means having levels that are within optimal ranges AND having it counterbalanced by progesterone in the second half of cycle.

Oestrogen in balance means:

  • Good mood
  • Good sleep
  • Sharp brain
  • Mojo, motivation
  • Stable weight
  • Strong bones
  • Good metabolism
  • Insulin sensitivity

There are oestrogen receptors on every cell in your body, which means it has far-reaching effects on all body systems, such as metabolic health, skin, bones, heart and even the gut. All systems feel the effects, whether it’s high, dominant or low.

Let’s now look at the 3 issues with oestrogen in your 40s in more detail.

1) Erratic fluctuations (the rollercoaster)

In your 20s and 30s, oestrogen was rising and falling in a relatively consistent and gentle way. Levels were not too high or too low at any given time. In your 40s however (from age 35+) oestrogen has become more of a rollercoaster with levels potentially soaring to almost 3x higher than ever before in your menstruating years, then crashing down to almost nothing. These erratic highs and lows impact your nervous system and create a multitude of symptoms, all at once.


  • Miserable periods (heavy, painful)
  • Breast pain
  • Mood swings, rage, irritability
  • Water retention (‘puffy’)
  • Headaches
  • Cysts
  • Histamine or mast cell reactions


  • Anxiety
  • Hot flashes
  • Night sweats
  • Insomnia/sleep issues
  • Low mood / depression
  • Migraines
  • Brain fog
  • Weight gain
  • Low energy, fatigue

2) Oestrogen dominance

Oestrogen dominates in the first half (follicular phase) of the menstrual cycle, but in the second half of the cycle (luteal phase) progesterone should be the dominating hormone. Each month/cycle, progesterone is ONLY made after/as a result of ovulation and ovulation becomes harder to achieve in your 40s. This means that in your 40s, progesterone is not made some or many more months compared to your 20s and 30s. When oestrogen is left ‘unopposed’ by oestrogen to ‘dominate’ the entire cycle, you get symptoms of oestrogen dominance, which are the same as the highs in the rollercoaster:

  • Miserable periods (heavy, painful)
  • Breast pain
  • Mood swings, rage, irritability
  • Water retention (‘puffy’)
  • Headaches
  • Cysts
  • Histamine or mast cell reactions

Being oestrogen dominant doesn’t necessarily mean having elevated levels of oestrogen in your body BUT If you’re always oestrogen dominant, it’s just as bad as having high levels of oestrogen.

3) Oestrogen Excess

This means having elevated levels in your body (outside (above) of the ideal range). This isn’t the same as oestrogen dominance because oestrogen can be the dominant hormone for you but still be within healthy range.

Genuinely elevated levels of oestrogen makes the roller coaster highs and the dominance situation worse in terms of symptoms experienced. Having high levels of oestrogen is also a risk factor for growth of fibroids, cysts and oestrogen driven cancers. Not always the case but definitely something to be aware of.

Causes of elevated oestrogen include, and can be a mix of:

  • Not clearing your used oestrogen out of the body properly
  • High alcohol consumption because the liver puts breakdown of used oestrogen to back of the queue when any alcohol is present
  • Compromised gut health and constipation (having a healthy, fully formed bowel movement less that once a day)
  • High intake of hormone-mimicking chemicals (such as those found in products that contain artificial chemicals such as plastics, body, face and hair care products, perfumes, household cleaning products, detergents, candles, plug-ins and air fresheners).

To prevent oestrogen from spiking too high AND from being above the ideal range generally, you need to use it and then LOSE it! Simply put, you MUST properly metabolise (break down) your used oestrogen and eliminate it from the body.

Used oestrogen gets broken down primarily in the liver in a 2 phase process. Once it’s been fully and safely broken down it is sent to the kidneys and gut for permanent excretion from the body via urine and stool (bowel movements). You must pass a healthy, fully formed bowel movement at least once a day in order to efficiently remove the broken down oestrogen from the body. Otherwise, old oestrogen left sitting in the bowels for too long can be reabsorbed BACK into circulation in your body, increasing your overall levels.


Some simple diet and lifestyle habits can help you address one or all 3 of these issues, as for most women, 2 or all 3 of these issues are occurring simultaneously.

Here are 5 ways you can support oestrogen in your 40s, to minimise the symptoms and have a MUCH SMOOTHER ride!

1) Support your body to ovulate each month (or as many months as possible) throughout perimenopause.

Whilst it does become harder to achieve ovulation in your 40s, you still really want to be supporting it until menopause. It IS possible to help your body to ovulate many more times (cycles) than it would have without your support. Read my blog post here, where I explain how you can support your body to ovulate more often.

2) Support and stabilise your nervous system

Managing stress is absolutely crucial in your 40s because your nervous system, which is responsible for your body’s stress response and resilience, is profoundly impacted by the oestrogen rollercoaster and declining progesterone. These 2 situations lead to elevations in the stress hormone cortisol, making you more sensitive to all stressors including certain types of more intense exercise and workouts.

Magnesium and the amino acid taurine are two nutrients that can support the nervous system and help to relieve hot flashes and improve sleep.

3) Supply your liver with the nutrients it needs to work efficiently

Certain foods, nutrients and botanicals can support the different detox pathways and phases in the liver such as omega 3 fish oil, rosemary, cruciferous vegetables, B vitamins (especially folate, B12 and B6), magnesium, SAMe and betaine (also called Trimethylglycine/TMG). If a person is low on these nutrients then liver processing of used oestrogen may be compromised.

4) Ensure healthy, DAILY bowel movements

Increasing good quality fibre from all vegetables, especially dark green leafy types and all the different colours of berries and veg, helps feed friendly bacteria and add bulk to your stool, both of which encourage healthy bowel movements. Also make sure you keep your colon well hydrated with clean water and herbal teas throughout the day and chew your food REALLY well!

5) Minimise hormone disrupting chemicals.

These are chemicals that ‘look like’ oestrogen and once inside the body they take the place of real oestrogen inside the cells, causing hormone havoc and increasing your total load of oestrogen. They come from artificial chemicals you are exposed to day to day, such as plastics and body, face and hair care products, perfumes, household cleaning products, detergents, candles, plug-ins and air fresheners. Filter your water, use glass, ceramic or stainless steel for cooking, heating, storing and drinking and switch to cleaner skincare brands such as Green People, Antipodes, Sukin, Ren, Neal’s Yard and Tropic and cleaner household cleaning and detergent brands such as Bio-D, Method and Attitude.

Even if you started with ONE of these tips you’ll be helping your perimenopause experience in a big way and should start to notice a difference in how you feel. You don’t need to make changes overnight, slow and steady always wins the race. Start with one thing and build from there once that first thing has become a fully instilled habit/change.

Which one might you need to address first?

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.

Download the Free Guide

A FREE, no-nonsense PDF guide to Mastering Perimenopause and learn how to master your hormones in your 40s for more energy, better sleep, balanced mood, easier periods and so much more.


Learn more about my signature course – Thrive Through Perimenopause – to start taking care of your hormone health once and for all, for a MUCH smoother ride in your 40s and beyond!

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