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Originally published on 14th November 2017 Last updated on 8th May 2021
As well as thyroid hormones, many other hormones are also part of the endocrine system, which all work in a delicate balance with one another. They regulate body temperature, metabolism, energy and reproduction.
Many thyroid patients, when piecing together their thyroid jigsaw puzzle, learn that they actually have more at play than just thyroid issues. They also have something called Oestrogen Dominance.
I’m one such thyroid patient who, after years on the combined contraceptive pill, with period issues such as menorraghia and irregularity as well as my thyroid conditions (hypothyroidism and Hashimoto’s), found out that I had oestrogen dominance; where the balance of oestrogen to progesterone is very ‘off’.
What Are The Signs?
What is Oestrogen?
Oestrogen is a hormone primarily produced by the ovaries and is responsible for the growth of the uterine lining during the first half of a woman’s cycle. Day one of the cycle is the first day of a woman’s period.
Progesterone is produced by the ovaries as well and its primary role is to prepare the uterus for conception. Both these hormones (oestrogen and progesterone) are present throughout your whole cycle but in varying amounts depending on where in the cycle you are.
Oestrogen dominates the first half and progesterone dominates the second half of your cycle.
So What Does ‘Oestrogen Dominance’ Mean?
Many of us with hypothyroidism have this hormonal imbalance, since the endocrine system is such a delicate balance of various hormones and when one part of that system (the hypothalamus, pituitary, thyroid, parathyroids, adrenals, pineal gland, reproductive organs, pancreas) goes awry, it can have a knock-on effect to others.
We already know that many of us have adrenal dysfunction in conjunction with hypothyroidism, for example, and adrenal issues can drive oestrogen dominance, as well as oestrogen dominance causing adrenal fatigue.
So, it’s well worth considering oestrogen dominance if you have symptoms, or are on thyroid medication but don’t feel hugely better.
What is The Link with Thyroid Disease?
The link between oestrogen dominance and hypothyroidism is hard to miss, considering that for every nine or ten women that suffer from hypothyroidism, only one man does.
Many medical professionals are now blaming oestrogen dominance for the cause of some hypothyroidism cases, as a non-autoimmune cause on its own, but also as a trigger for the autoimmune version of hypothyroidism: Hashimoto’s Thyroiditis. Which around 90% of us with hypothyroidism have. 
How Do I Know if I Have Oestrogen Dominance?
To check if you have oestrogen dominance, you can test your progesterone level at its peak, around day 21 of your cycle (this may differ or be difficult to predict if you have an irregular cycle), and oestrogen on cycle days 3-5.
Testosterone can be tested at anytime during the month and checking FSH is also often beneficial.
These tests give an overview of your sex hormone health and can help determine if you have an imbalance in them.
The test results should be able to indicate whether you have an imbalance in your ratio of oestrogen to progesterone, but any symptoms of oestrogen dominance form part of the diagnosis too. Many functional practitioners diagnose and treat oestrogen dominance without test results, but you may feel more reassured to test them too.
Where Can I Order Testing for Oestrogen Dominance?
Who Can Help Me?
In terms of medical professionals, naturopathic and functional practitioners and doctors are often preferred by thyroid patients trying to combat oestrogen dominance. I attempted to overcome oestrogen dominance on my own for a year or two before eventually seeking out a functional medicine practitioner as it was very complicated. My GP acknowledged that it was likely an issue but his only suggestion was to put me back on a contraceptive pill, which only masks the issue and does not treat it.
I found working with a FMP immensely helpful.
So, How Do You Combat Oestrogen Dominance?
First of all, there are some simple changes you can make and things to be aware of. These are things my FMP had me do too.
- You should ensure that you’re eating plenty of fibre and that your bowels are moving regularly. Bowel movements of at least once is ideal, so eat plenty of fibre-rich food (though not close to taking your thyroid meds or it can affect absorption). You can also try magnesium supplementation to get bowels moving more regularly.
- Start your day with half a lemon squeezed in to some hot water.
- Drink plenty of water throughout the day.
- Explore leaky gut and digestive enzymes to get your digestive system working more efficiently.
- There is some belief that eating meat and other products of animals can contribute to high oestrogen levels too, since they contain hormones from the animal itself, so sourcing protein from other places instead of relying on these products entirely may help to lower levels somewhat. However, the boat is still out on that one.
- Look for BPA-free water bottles, storage containers and minimise exposure through cosmetics and other household products. Read this article about oestrogen-mimicking chemicals and how to limit exposure to them.
- Avoid using hormonal contraceptives, which inevitably upset the oestrogen-progesterone balance and even when you come off them, can take years to correct (like me).
- Products such as DIM and broccoli sprout extract can also help to clear excess oestrogen. Broccoli sprout extract improved my bowel movements, acne and migraines associated with oestrogen dominance.
Easier said than done, I know! But stress is linked to sex hormone levels very delicately.
When a person is stressed, the adrenal glands pump out extra cortisol, the stress hormone. Stress can come from mental stress, emotional and physical and when this goes on for a long period of time, you can develop adrenal dysfunction, or ‘adrenal fatigue‘, a condition many thyroid patients have. However, many aren’t even aware that they have it.
Symptoms include ongoing fatigue, sugar and salt cravings, headaches, sleep disruptions, anxiety, feeling irritable and so many more. When this becomes chronic, it disrupts the normal circadian rhythm and the stress response of the Hypothalamus-Pituitary-Adrenal axis. Eventually, the adrenals start to run low on cortisol and begin ‘stealing’ progesterone to convert in to more cortisol, depleting levels even further, increasing the imbalance between progesterone and oestrogen.
This stress and pressure can then inhibit the liver from converting thyroid hormone T4 (the storage hormone) to T3 (the active hormone), which contributes to us feeling like rubbish and can also prevent it from detoxifying the excess oestrogen. When this happens, the oestrogen can start to build up in tissues and cause oestrogen levels to rise even further.
Come Off Any Contraceptive Pill
This will not help your hormonal imbalances but instead worsens it.
What can be frustrating is that whilst conventional medicine recognises that increased oestrogen levels can lead to increased chances of fibroids and breast cancer for example, they don’t typically look to address the issue directly, looking at the body and endocrine system as a whole. If you’ve attempted to address oestrogen dominance yourself and aren’t having much luck, I strongly recommend seeking out a naturopathic or functional doctor.
Progesterone supplementation (natural progesterone cream) is also often used, but really should only be used with guidance from a medical professional. I attempted to treat my oestrogen dominance with progesterone cream and really didn’t get very far. It can also be dangerous.
Address Your Gut Health
In my own case of oestrogen dominance, I had to address my leaky gut and Candida (yeast overgrowth) to get on top of it. I was put on a Candida diet for a few months, adding in digestive enzymes, apple cider vinegar, bone broth and probiotics, and then encouraging more regular bowel movements by supplementing Magnesium Citrate, so I could eliminate the excess oestrogen yeast. A UK test for Candida can be found here and a US test here.
Some good books for further reading on this include:
Beyond The Pill by Dr. Jolene Brighten (I highly recommend reading this one)
Have you experienced oestrogen dominance or suspect you do?
You can click on the hyperlinks in the above post to learn more and see references to information give, but further information can also be found at:
The book Be Your Own Thyroid Advocate: When You’re Sick and Tired of Being Sick and Tired, which details the many things Rachel had to do to get her thyroid and overall endocrine health back on track. Learn to advocate for yourself.
Rachel Hill is the highly ranked and multi-award winning thyroid patient advocate, writer, speaker and author behind The Invisible Hypothyroidism. Her thyroid advocacy work includes writing articles, authoring books, producing her Thyroid Family email newsletters and speaking on podcasts, as well as being a founding board member for the American College of Thyroidology. She is well-recognised as a crucial and influential contributor to the thyroid community and has a large social media presence. Her books include “Be Your Own Thyroid Advocate” and “You, Me and Hypothyroidism”.