How Estrogen Dominance Can Ruin Your Thyroid Health

In the medical world high estrogen levels refer to the estrogen dominance which is a condition where the amount of estrogen is not balanced by a sufficient amount of progesterone.

Estrogen is a “female” hormone that occurs naturally in both men and women. There are three major types of estrogen: estradiol, estrone and estriol that are produced in the proportion 15/15/70 by the woman’s body. All three hormones are necessary for optimal health, however high levels of estrogen can cause many health problems.

What many women do not realize is that all following conditions are signs of estrogen dominance: PMS, weight gain, blood clots, breast cancer, breast tenderness, lumps and cysts, migraines, endometriosis, fibroids, PCOS, water retention, mood swings, depression, anxiety, autoimmune diseases, allergies, asthma, insomnia and thyroid problems.

Estrogen dominance occurs when:

  • Estrogen is high and progesterone is low
  • Estrogen is high and progesterone is normal
  • Estrogen is normal and progesterone is low

Estrogen dominance reflects an imbalance between the estrogen and progesterone ratio rather than a comparison between their levels.

How estrogen dominance affects your thyroid

Many women in their 30s, during peri- and menopause are overloaded with estrogen that is not compensated by sufficient amounts of progesterone. Most of them experience symptoms that are attributed to other conditions including thyroid disease because estrogen dominance can affect and cause a dysfunction of many other organs and systems.

3 Types of thyroid imbalances caused by estrogen dominance:

1. Estrogen dominance can affect the conversion of T4 into T3 thyroid hormone and result in low T3 levels. In this case nothing is wrong with the thyroid gland and hormone production, however a woman can feel hypothyroid.

2. Too much estrogen can block the uptake of thyroid hormone, promoting hypothyroid symptoms.

3. If estrogen dominance is present thyroid binding protein called thyroid binding globulin (TBG) that carries thyroid hormones to the cells can become significantly increased. Levels of T4 and T3 thyroid hormones can become low because they get attached to the thyroid binding globulin. This effect prevents thyroid hormones from entering the cells and can result in hypothyroid symptoms.

Unfortunately, it is very common that women with estrogen dominance are misdiagnosed for having hypothyroidism and are put on a thyroid medication. After the estrogen dominance is corrected, for example by adding bio-identical progesterone and/or by lowering high estrogen levels, the need for thyroid medication decreases and women often can successfully get off thyroid medication.

Estrogen dominance is one of the key components of the suppressed immune system and contributes to the development of autoimmune conditions including Hashimoto’s and Grave’s diseases. Often balancing estrogen with progesterone is not enough to offset the negative effects of estrogen because it still remains at the high levels even after progesterone becomes normal.

During the perimenopause progesterone levels decline faster than estrogen. By the time a woman reaches menopause the progesterone levels are low while estrogen is still present in the body at about half of its pre-menopausal levels. This is one of the factors explaining why the incidence of hypothyroidism and Hashimoto’s disease drastically increases at the time around the menopause.

You can learn more about the exact mechanism how estrogen dominance causes hypothyroidism and autoimmune thyroid disease and how to overcome it by lowering high estrogen levels in the Hypothyroidism Revolution program.

Too much estrogen can come into your body from many different sources:

  • Inadequate production of estrogen and progesterone by your body
  • Phytoestrogens from plant sources such as food in our diet
  • Xenoestrogens from using synthetic products in your household and environment

Phyto- and xenoestrogens can act as endocrine disruptors that mimic estrogen behaviour and can alter the function of the whole endocrine system including the thyroid.

They are found in everything from plastics, household cleaners, cosmetics, dairy products, solvents and many other items that most women are exposed to every day.

Most common causes of estrogen dominance

1. Overproduction of estrogen compared to progesterone due to hormonal imbalances.

2. Stress is one of the major contributing factors to hormonal imbalances in women over 30. When you are under chronic stress your body produces the hormone cortisol at the expense of progesterone and other major hormones.

When too much progesterone is converted into cortisol to satisfy the body’s requirements for the cortisol production it is called “progesterone steal”. Progesterone levels become low and can result in estrogen dominance effect even when estrogen levels are normal.

During periods of chronic stress hormone cortisol becomes elevated and reduces the ability of the liver to clear excess estrogen from the blood. Accumulation of estrogen leads to the elevated thyroid binding globulin (TBG) and low levels of free T4 and T3 thyroid hormones that ultimately result in hypothyroid symptoms.

3. Birth control pills and hormone replacement therapy in the form of bio-identical or synthetic estrogen may interfere with your thyroid and cause common symptoms of hypothyroidism like fatigue, weight gain, constipation, dry skin and hair loss.

There are two types of birth control pills: one that contains only synthetic estrogen and another one that is a combination of synthetic estrogens and progestins. Depending on the type and brand birth control pills can increase estrogen levels and create a state of estrogen dominance.

4. Diet is one of the major causes of estrogen dominance. Eating fruits and vegetables containing pesticides, meats from commercially raised cattle and poultry, drinking more than two cups of coffee or caffeinated beverages per day, high sugar diet, fast food and processed food all contribute to high estrogen levels.

Many consumers do not know that seeds of wheat and many other grains are doused with estrogen compounds to aid their growth, regular crops are sprayed with pesticides that contain estrogen-mimicking compounds, cows and cattle are given estrogen to make them produce more milk and reach a higher weight.

In fact, the meat of cows that were treated with hormones has been found to contain up to 5 times the amount of estrogen as untreated cattle. Furthermore, even higher levels of estrogens were found in chickens.

Phytoestrogens that come from unfermented soy products disrupt endocrine pathways and have the potential to cause many negative effects on your health including low thyroid function, thyroid cancer, infertility and promote breast cancer in adult women.

The incidence of autoimmune thyroid disease is higher in infants that were put on soy formula.

Nutritional deficiencies such as low vitamin B6 and magnesium impair the neutralization of estrogen in the liver and are very common in people with hypothyroidism.

5. Obesity can contribute to estrogen dominance because fat cells can produce estrogens and xenoestrogens have a tendency to accumulate in body fat tissue. Because of this effect overweight women can have the same levels of estrogen around menopause as they had in their 30’s while progesterone levels declined creating the state of estrogen dominance.

6. Anything that affects liver function can reduce clearance of estrogens due to the impaired detoxification process. Excessive alcohol consumption, drugs that affect liver function and liver disease such as cirrhosis reduce the breakdown of estrogen and its elimination from the body. In addition, hypothyroidism affects your liver function in a way that impairs thyroid hormones conversion. Learn here what can be done about it.

7. Environmental xenoestrogens like pesticides, plastic and pollution can mimic estrogen behavior. Some plastics used to pack or reheat your food actually leak synthetic estrogens and other toxins into your food.

One often ignored source of xenoestrogens is industrial solvents such as alcohol like aldehydes like acetaldehyde, fingernail polish and fingernail polish remover, methanol, glycol like ethylene glycol and ketones like acetone that are often used in cosmetics, cleaning products, carpet, paints, glues, varnishes, and other types of finishes,  fiberboard and other processed woods.

This type of xenoestrogens quickly enters the body via the skin and has a tendency to accumulate in the body fat tissues and nerve covering myelin.  Other hidden sources of xenoestrogens are pesticides and herbicides that are commonly used for lawn and garden care and indoor insect sprays.

Estrogens from all sources add up and have a cumulative effect that can result in estrogen dominance from the years of chronic exposure.

How estrogen dominance is diagnosed

Depending on what doctor you attend s/he can choose to order the following tests to determine if you have estrogen dominance and its cause:

Hormone saliva test gives you information about all major hormones. If your sex hormones such as DHEA and testosterone are low, estrogen (estrodiol) is normal or high and progesterone is low you are estrogen dominant.

There are four simple tests that can help to determine whether or not your estrogen is interfering with your thyroid hormone: TSH, T4, T3 uptake and free T3. If your lab test results show normal TSH and T4 but your T3 uptake and free T3 are low, estrogen dominance is causing your hypothyroid symptoms due to under-conversion of the inactive T4 into the active T3 thyroid hormone.

Thyroid binding globulin test (TGB) helps to determine if too much T4 and T3 thyroid hormones are attached to this thyroid binding protein and if the body has enough free or usable T4 and T3 to function properly. Estrogen dominance is a major factor for elevated thyroid binding globulin.

10 Tips on how to protect your thyroid from xenoestrogen exposure

By reducing your exposure to natural and man-made estrogens in your environment you will help your thyroid gland and your endocrine system to function more efficiently. Even small changes are the steps in the right direction and can make a big difference for your thyroid health.

1.    Try to add more plant-based foods to your diet. Studies show that plant foods contain over 5000 different types of sterols that have progestogenic protective effects.

2.    Choose fresh whole foods over the processed and fast foods. Women who eat more whole foods have a significantly lower incidence of estrogen dominance.

3.    Try to switch to organic fruits and vegetables, especially those from the following list that have a tendency to accumulate pesticides and herbicides: Nectarines, celery, apples, lettuce, strawberries, grapes, blueberries, peaches, potatoes, bell peppers, and cucumbers.

4.    Eliminate unfermented soy from your diet and be aware that soy is hidden in many of the foods that we consume every day and also in packaged foods.

5.    Choose naturally raised and grass-fed pastured meats over commercial and organic meats.

6.    Do not use plastics with a recycling symbol marked as 3, 6, or 7. These are poor quality plastics that are known to leak xenoestrogens and other toxins into the stored food and water especially if reheated or left in the sun. Never microwave foods in plastic containers or covered with plastic wrap.

plastics 3Number 3 plastics contain vinyl (V) or PVC. They are found in shampoo bottles, wire jacketing, siding, window cleaner and detergent bottles, medical equipment, clear food packaging, cooking oil bottles, windows, piping.



plastic 6Number 6 plastics contain polystyrene (PS) and are found in disposable plates and cups, compact disc cases, aspirin bottles, egg cartons, meat trays, carry-out containers, insulation, light switch plates, vents, Styrofoam products, rulers and foam packing.



big water bottleNumber 7 plastics are a mix of different types of plastic that do not fit in any other category and most common of them are iPod and computer cases, sunglasses, ‘bullet-proof’ materials, three- and five-gallon water bottles, DVDs, signs and displays, certain food containers and nylon.

Glass storage containers are always preferable to plastic when it comes to food storage including bottled water.

7.    Most women use cosmetics and household cleaning products every day but do not know that many ingredients contain xenoestrogens. There is not one person I have ever met among beauty advisers or cleaning ladies who had autoimmune Hashimoto’s disease and realized that the everyday exposure to xenoestrogens due to their profession is the main cause of their health issues.

The problem is that the cosmetic industry and their ingredients are self-regulated and are not controlled by the government. By current law the cosmetic industry is not obligated to put all types of estrogens on the label among other ingredients they use.  

Most common xenoestrogens that you can see on the cosmetics labels:

Parabens are substances that are used in low amounts as a preservative and can be labeled as methylparaben, ethylparaben, butylparaben, isobutylparaben, propylparaben.

Placental extracts contain hormones estrogen, estrone and progesterone as contaminants. They are found in body and skin creams, moisturizers, shampoos and conditioners.

UV screens are added in substantial amounts to sunscreens, moisturizers, shampoos, conditioners, perfumes, hair sprays, styling gels, lipsticks, facial creams, foundations, liquid hand soaps, body wash, insect repellants, nail polish and polish remover and are labeled as homosalate, oxybenzone, benzophenone-1, benzophenone-2, octinoxate, sulisobenzone, and 4-MBC (used in Europe). Many commonly used UV-screens are absorbed by the skin and get into the bloodstream. 

By choosing cosmetic products with all-natural ingredients you can significantly reduce your toxicity exposure. This is the best way how you can replace toxic cosmetic and household products with better alternatives.

8. Reduce stress. Simple diet and lifestyle modifications can support thyroid function and lower the impact of stress on your overall health and well-being.

9. Get off birth control pills and if possible, consider alternatives to birth control pills. Choose bio-identical hormone therapy over synthetic HRT and make sure that estrogen is always balanced by sufficient amounts of progesterone.

Many people don’t realize that medications and drugs also can be harmful. If you don’t believe me make this simple exercise: Put on the table ALL medications and supplements that you are currently taking and read about possible side effects and drug interactions they may cause.

If you are on Synthroid you may discover that this medication has hair loss as a common side effect.

If you are taking Omega-3 fish oil as a supplement and low dose Aspirin to prevent blood clots you may find out that these two substances intensify effects of each other.

Antibiotics kill not only pathogenic but also all good gut bacteria leaving you with dysbiosis, constipation, indigestion and when overused with antibiotics resistant bacteria and infections.

And the list goes on and on.

Just because something is being sold in the pharmacy, doesn’t mean that it is 100% safe. Using herbs guide and natural alternative treatments often has less side effects and more health benefits than drugs.

10. Reduce toxic and hormonal load by detoxifying your gut and liver.

Did you know that thyroid health conditions, mood swings, symptoms of menopause and PMS are EASILY alleviated when you detoxify your liver?


Because your liver helps your body to break down and eliminate the excess of hormones including natural and man-made estrogens. A sluggish liver that is very common in people with hypothyroidism leads to higher levels of toxicity and does not eliminate endocrine disruptors effectively.

By saying detoxification I do not mean a detox-in-a-box, detox pills, or unhealthy master cleanse-like solutions that produce absolutely no long-term health benefits. It is not about quick fixes but about focusing on improving your thyroid and overall health.

To help you to get started I would like to share with you the only 7 Day Organic Detox that can cleanse your body, reduce inflammation, enhance nutrient absorption, and leave you Feeling Better!

You won’t be starving because you’ll actually be eating real food! REAL LIFE is not about living on JUICE. It’s the world’s most Sustainable detox/cleanse.

This 7 Day Organic Detox program is completely natural and food based which is the best way to alleviate existing and prevent future hormone-related issues and support your thyroid function by improving T4 to T3 thyroid hormone conversions and eliminating xenoestrogens and other hormonal by-products.

Organic Detox

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About Marina Gutner, PhD

Marina Gutner, PhD, researcher, medical writer, thyroid blogger, founder and Admin of Outsmart Disease who writes about life-changing treatments for hypothyroidism, Hashimoto's thyroiditis and autoimmune disease and how to balance hormones in women