Perimenopause 101: What Every Woman Should Know

Just when you’re feeling like you’ve mastered your hormones in your 30s and things are going smoothly, your 40s can throw you a hormonal curveball!

If you’ve moved into your 40s and you’re feeling more tired or fatigued, you’ve got worse PMS symptoms, heavier periods, sleep issues, anxiety, headaches, and brain fog – rest assured you are not alone. These are some of the typical symptoms we can start to experience during perimenopause.

The purpose of this blog is to help you understand exactly what perimenopause IS; what’s happening to your body, when, WHY, and what you can do to support yourself.


Perimenopause is the natural phase of womanhood where your hormones are starting to shift and change as your body starts its slow and gradual transition towards eventually going 12 consecutive months without a period, also known as menopause. Your body moves into this phase from mid to late 30s and it’s common to start noticing symptoms or changes relating to it from early to mid 40s.

Perimenopause is NOT menopause. It’s everything BEFORE menopause.

A “menopausal” woman is a woman who has already reached menopause (1 day) and is now in postmenopause. A woman in her 40s who’s still having periods but experiencing perimenopausal symptoms is not “menopausal”, rather she is moving through PERImenopause.


As you move past your mid 30s, the communication between your brain and ovaries starts to change. This brain to ovary communication is what has governed your menstrual cycles since your first ever period as a teen. In your 20s and earlier 30s their communication was fairly robust, but as you move past about 35, the brain and ovaries stop communicating with each other as well or clearly.

This soon starts to result in changes in output of progesterone and oestrogen.

Its Starts With Changes To Progesterone

Firstly, progesterone levels start to decline, which is due to cycles in which you ovulate becoming fewer. Ovulation is how you make progesterone.

At first it may just be the odd cycle here and there where you don’t manage to ovulate and the further you progress through your 40s the more non-ovulatory cycles you may have and therefore for more progesterone declines.

Declining progesterone starts to create symptoms related to nervous system stability because progesterone is a calming, nervous system supportive hormone. Problems falling and or staying asleep at night, anxiety, and irritability are common in the initial stages of perimenopause.

Then Comes Changes To Oestrogen

The next characteristic of perimenopause is erratic fluctuations in oestrogen AND higher levels than we saw in our previous decades. This new oestrogen rollercoaster can see levels of oestrogen rising 3 times higher than ever before then crashing down to really low levels, over and over again throughout the month.

Add to this a decline in progesterone levels, and you’ve got the perfect stage set for symptoms such as heavy periods, breast pain, brain fog, low mood and mood swings, anxiety, irritability, sleep issues, longer or shorter cycles, headaches, migraines, weight gain, loss of libido, hot flushes, and night sweats.

what is perimenopause
Diagram showing decline in progesterone, high and erratic nature of oestrogen in early perimenopause, and lower and erratic oestrogen in the later stages of perimenopause.

Symptoms Resulting From The Oestrogen Rollercoaster

The HIGHS = heavy periods, painful periods, breast pain, headaches, bloating, mood swings.

The DROPS = hot flushes, night sweats, headaches, migraines, low mood, flat mood, low energy and fatigue, low libido, little zest for life, joint aches and pains.

Symptoms Resulting From Declining Progesterone

Less stress resiliency, trouble falling asleep and or staying asleep, anxiety, and irritability.

Another situation that arises during perimenopause is something known as “unopposed oestrogen” or “oestrogen dominance”. This is a situation that occurs when oestrogen is not balanced out or “opposed” by its partner hormone progesterone. Progesterone in the calming yin to oestrogens wonderful yang. As progesterone levels are on the decline (due to less and less ovulatory cycles) oestrogen is not only high and erratic but it’s also left unopposed.

Symptoms Resulting From Unopposed Oestrogen

Heavy periods, painful periods, breast pain, headaches, bloating, mood swings, and new or worse PMS.

When you consider that we move into perimenopause from mid to late 30s and that the average age of reaching menopause is 51 (give or take), I hope you can see that perimenopause is a lengthy, transitional phase. It’s stormy waters that are eventually followed by a calm after the storm, which is menopause (1 day), then you are in postmenopause / postmenopausal forever more.

That being said, let’s look at a more detailed breakdown of the various stages from start to finish, with the “finish” being finally achieving / reaching menopause.


Very Early Perimenopause: 38 – Early 40s

Here you may experience subtle changes related to nervous system and mood as progesterone is dropping, such as:

  • Very mild changes in mood
  • Very subtle changes in things like confidence, sociability, outgoing nature etc.
  • Fleeting anxiousness
  • No change to menstrual cycles

Early Perimenopause: Early – Mid 40s

Here, progesterone is dropping even more while oestrogen remains high / gets higher, you may experience:

  • Menstrual cycle has started to change. Usually shorter in length by 5 or so days
  • Flow is heavier, often with flooding or clotting

Mid To Late Perimenopause: Mid To Late 40s

Here, oestrogen levels are fluctuating more wildly AND spiking up to 2-3 times higher than they were before perimenopause. This results in neurological symptoms such as:

  • Hot flushes
  • Night sweats
  • Brain fog
  • Cycle length gets longer as ovulation occurs less and less. Periods are missed, resulting in cycle lengths of 60 days plus

Late Perimenopause To approaching Final Menstruation: The Graduation To Menopause

  • Oestrogen is now consistently lower
  • The turbulent fluctuations are over
  • You are almost at the 12 month mark of having had no period
  • You’ve reached the 12 month mark (one year following your final period) and you have moved into the most stable hormonal phase


Leverage Nutrition And Lifestyle Habits

You have the power to minimise your symptoms or make them go away completely! As long as you know what your body needs in order to support against the rocky hormonal ride of your 40s.

Isn’t that great?!

Perimenopause does not need to be a phase to dread or hate. After all, it’s a natural phase of our amazing womanhood, and we owe it to ourselves to know what’s happening and know how to support ourselves.

I cannot emphasise enough how impactful nutrition and lifestyle habits are on your entire perimenopause experience. They can improve the severity or intensity of symptoms 10-fold if you know how to leverage them.

You can leverage nutrition and lifestyle habits to:

  1. Calm the oestrogen rollercoaster as much as possible and shelter your body and nervous system from sharp highs and lows.
  2. Support your body to ovulate more months than it would have done without intervention (so you can make progesterone more often and minimise its decline).

In my blog called “How To Get Rid of Perimenopause Symptoms” I’ve outlined some of the most helpful habits to start to implement for a much smoother ride. Head here to read it.

Identify And Address Pre-Existing Health Imbalances

Any pre-existing hormonal imbalances or health niggles can set the stage for a more rocky perimenopause, amplifying symptoms.

The severity of many perimenopause symptoms are a direct consequence of imbalances in hormones such as cortisol and insulin, gut and digestive health issues, hormone metabolism and detoxification issues, nutrient deficiencies, xenoestrogens, and toxins.

This decade (and a bit!) provides a window of opportunity for you to start to address various areas of your health and to really start to focus on your nutrition and lifestyle habits. This is a time to really start to optimise and safeguard your health!

For A Smoother Perimenopause Experience And Graduation Into Menopause You Need:

  • Good blood sugar regulation and optimal protein intake
  • Good sleep and healthy circadian rhythms
  • Good stress management/nervous system support
  • Efficient liver detoxification processes, particularly for healthy metabolism and clearance of used hormones
  • A healthy gut and good digestion
  • Healthy muscle mass
  • To identify and address any potential autoimmunity, chronic infections such as mould toxicity, pathogenic gut bacteria or parasites, viruses, or chemical burdens
  • To identify and address any nutrient deficiencies such as iron, B12, folate, and vitamin D
  • To identify and address any thyroid issues such as under or overactive thyroid hormone production or Hashimoto’s (thyroid autoimmunity)
  • Blood work information for markers such as cholesterol, triglycerides, HbA1C, fasting glucose, as well as immune, kidney, and liver markers.

In my private practice with clients, we start with the ‘low hanging fruit’ and then develop things from there, IF needed. Sometimes a person simply needs to increase their protein intake with all their meals and they already start to feel so much better. Then they have the energy and inclination to start working on improving their sleep. Once they’re getting better sleep they want to dig a little deeper and address other areas such as their stress load, their gut and digestive health, and so on. For some we can stop here, for others we need to go further.

I hope this blog has provided you with some positive and empowering insight into this truly impressive transitional biological phase. If you’d like my help and support as you navigate these stormy waters, click here to learn more about how we can work together.

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

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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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