In this episode, Dr. Eric Osansky explores the complex relationship between estrogen and thyroid health. While estrogen is often associated with reproductive health, it also plays an important role in thyroid hormone activity, immune function, metabolism, and overall hormonal balance. Dr. Eric explains how estrogen can influence thyroid hormone availability through thyroid-binding globulin (TBG), why both high and low estrogen levels can create problems, and how hormonal imbalances may contribute to thyroid symptoms in women with Graves’ disease and Hashimoto’s thyroiditis.
Dr. Eric also discusses estrogen dominance, progesterone balance, and the connection between estrogen, thyroid autoimmunity, and life stages such as puberty, pregnancy, postpartum, perimenopause, and menopause. He reviews the important role of gut health—particularly the estrobolome and beta-glucuronidase—in estrogen metabolism, along with the impact of chronic stress, xenoestrogens, environmental toxins, liver function, and detoxification. In addition, he explains the pros and cons of various hormone testing methods, including blood testing and the DUTCH test, while highlighting nutrients and supplements that may support healthy estrogen metabolism when appropriate.
The episode concludes with practical recommendations for supporting both thyroid and estrogen balance through nutrition, stress management, gut health, and personalized testing when needed. If you want a clearer, more balanced understanding of the thyroid-estrogen connection and how hormone balance affects autoimmune thyroid health, you’ll get a lot out of this episode.
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Dr. Eric Osansky:
Let’s talk about the thyroid-estrogen connection. It is often overlooked, yet many women with thyroid conditions have estrogen imbalances. There are a number of symptoms shared by thyroid conditions and estrogen imbalances, including fatigue, weight changes, brain fog, mood swings, anxiety, sleep disturbances, menstrual irregularities.
I assume most people know what estrogen is, but let’s talk about the different forms of estrogen. There are three main types. There is estrone, E1; estradiol, E2; and estriol, E3. Not going to get into great detail about the types of estrogen, but estriol is, I don’t want to say least important because they are all important. If you are pregnant, estriol is definitely important. Estrone and estradiol are the two major forms of estrogen.
Estrogen has a lot of important functions. Most are familiar with its function in reproductive health. It also plays a role in bone health, mood regulation, metabolism.
Estrogen tends to get a bad rap at times. It’s not a bad hormone. All the hormones are important. Too much estrogen is not a good thing. Too much of any hormone is not a good thing. Too much thyroid hormone is not a good thing, as those with hyperthyroidism know.
Estrogen really isn’t good or bad. You want to have estrogen just like you do other hormones in balance. The goal is balance, not suppression. If someone has hyperthyroidism, including Graves’, you don’t want to suppress thyroid hormone completely. You want to balance them.
As far as how estrogen influences thyroid function, you have what’s called thyroid binding globulin (TBG). TBG is a protein that binds to thyroid hormone. Thyroid hormone could also bind to other proteins. This is the main protein that it binds to. It’s a transport protein, where it transports thyroid hormone throughout the bloodstream. Most of the thyroid hormone is actually bound to TBG. You also have what’s called free thyroid hormone, which is not bound to TBG. They could both have value as far as testing for thyroid hormone. I definitely prefer looking at the free thyroid hormones.
When it comes to TBG, higher estrogen levels can increase TBG. If you have high estrogen, then you will probably have higher TBG levels. The significance of this is if you have increased TBG, then you have more thyroid hormones binding to this protein. In all likelihood, this will reduce the available free thyroid hormone. You will have less free thyroid hormone, free T4, free T3 in the bloodstream and more total T4 and/or potentially total T3.
This is why some women might feel hypo even if they’re taking thyroid hormone replacement. This is something that many doctors don’t consider. I’m not saying everybody needs to test TBG. I can’t say I test TBG in everyone. There is a time and place for it. You definitely want to consider the relationship between estrogen and the thyroid, which many practitioners do not.
When looking at the thyroid, this is also why you want not just to look at TSH. You want to evaluate T4 and T3. You could do total T4 and total T3 along with free T4 and free T3. If I had to choose, I would say look at free T4 and free T3.
This is especially true with hyperthyroidism. We know there is increased output of thyroid hormone. It’s not important to test total T4 or total T3. With hypothyroidism, there is an argument for testing total T4 and free T4 along with free T3. Some practitioners, including endocrinologists, will look at free T4 and total T3 instead of free T3. I do see that a lot.
Let’s talk more about how estrogen can influence the availability of thyroid hormone. As I mentioned, estrogen can increase the production of TBG, which takes place in the liver. When TBG levels rise, you get more thyroid hormone bound to TBG, and less thyroid hormone remains free and biologically active. As a result, some women may have normal total thyroid hormone levels.
Another reason why you might look at total T4 and total T3. It might look fine. They might experience symptoms consistent with reduced thyroid hormone activity. Less hormone is available to the tissue. The reason why less hormone is available is because it’s bound to TBG.
If you did do a blood test, then you would probably see TBG elevated, or at least on the higher side. It might still be within the range, but it might be on the higher side of the range.
Estrogen may affect thyroid hormone receptors as well. Some research suggests that estrogen can influence the expression activity of thyroid hormone receptors. Estrogen may affect how responsive certain tissues are to thyroid hormone.
Think of it like insulin resistance. With insulin resistance, you have plenty of insulin. It’s not getting into the cell. Similar scenario here. More research needs to be done in this area, but this may explain why two people might have identical thyroid lab results but may experience very different symptoms, especially when other hormone imbalances are present.
Keep in mind that thyroid hormones work by entering cells. All hormones have to bind to a cell receptor. When thyroid hormone does that, specifically T3, which is the active form of thyroid hormone, it binds to the cell and activates metabolic processes. Estrogen can influence numerous cellular signaling pathways. It can influence the mitochondria gene expression. All of this may affect how officially the tissues respond to thyroid hormones. This doesn’t necessarily mean that estrogen directly blocks thyroid hormone action.
In order to have optimal thyroid function, there are a lot of different factors. We spoke about the role of the adrenals and the role of the gut. All these are important, especially with autoimmune conditions like Graves’ and Hashimoto’s. You need a healthy hormonal environment as well. Estrogen is a big part of that environment.
Let’s focus on hyperthyroidism for a couple of minutes. Then we will talk more about hypothyroidism. With hyperthyroidism, for those women who are cycling, and this presentation will benefit women of any age. But for those who are cycling, many times, you will get lighter periods. You may have missed periods. You will often have shorter periods, too. Irregular cycles. You could have fertility challenges. Hyperthyroidism affects hormone metabolism and can have an impact on estrogen.
I mentioned TBG. If you have too much thyroid hormone, that could also increase TBG. That could decrease availability. Usually with something like Graves’, even if you see higher TBG levels on a blood test, you will see elevated T4 and T3 levels. Especially in hyperthyroidism, I don’t think there is never a time and place for testing TBG, but I typically don’t look at this.
With Graves’ and estrogen, estrogen can also partially explain why autoimmune conditions are more common in women. Women account for about 75-80% of all autoimmune disease cases. Most people I work with are women. I’m one of the lucky guys who developed Graves’, and I have seen men over the years. I’m not the only one.
There are multiple factors involved. I’m not saying estrogen is the only factor, but it is a potential factor. Estrogen does play a role in immune system health. You don’t want too much estrogen or too little estrogen. If you have too much estrogen, that can increase the activity of certain immune cells. This could be beneficial. You want healthy estrogen for a healthy immune system. Fighting infections.
If you have too much estrogen, it can potentially increase the likelihood of autoimmunity occurring, just like enhancing the immune response potentially. There is also concern with low estrogen levels. Estrogen is important for a healthy immune system. If you have too little estrogen, that could have a negative effect on immune health, which could explain why some women in post-menopause will develop autoimmune conditions such as Graves’ or Hashimoto’s. It’s usually not the only factor, but it is a factor to consider.
Progesterone also has immune balancing and anti-inflammatory properties. One reason why many women with autoimmune conditions experience symptom improvement during pregnancy is that progesterone levels rise a good amount. Along with other pregnancy-related immune shifts, when you’re pregnant, especially moreso with Hashimoto’s, you have greater immune tolerance. On the other hand, if you have Graves’, you’re more likely to experience immune shifts, where you’re more symptomatic during pregnancy. Everybody is different.
Getting back to progesterone. This doesn’t mean that progesterone prevents autoimmunity. It does have a calming effect. It is important when it comes to the health of the immune system. If you have low progesterone levels, that might make you more susceptible to autoimmunity, while if you have adequate progesterone levels, that could help create a more balanced immune environment.
You’ll notice that hormonal transitions are common autoimmune trigger periods. Puberty, we are seeing unfortunately more and more teenagers developing autoimmune conditions.
I hate to see these hormone transitions as triggers. When I say they are trigger periods, it doesn’t mean the hormones themselves are triggers. There usually are other factors. Puberty, pregnancy. Sometimes you can get an exacerbation of Graves’ during pregnancy. Post-partum. Perimenopause. Menopause. Post-menopause. These hormone shifts can be a factor, but the shifts themselves are not necessarily triggers. They can be straws that broke the camel’s back.
There are usually other triggers and underlying imbalances as well. In previous episodes, I discussed the triad of autoimmunity, also known as the three-legged stool. In order for Graves’ and Hashimoto’s to develop, you need a genetic predisposition, exposure to one or more environmental triggers, and an increase in intestinal permeability, also known as a leaky gut.
Even more teenagers are having gut dysbiosis, gut imbalances, leaky gut. There are definitely other triggers. All the toxins and toxicants we are exposed to definitely aren’t helping. There are other factors as well. That’s what’s making them more susceptible. It’s not the hormones themselves, or else that wouldn’t explain the increased incidence because people have always gone through puberty.
Pregnancy, post-partum, perimenopause, menopause, these hormonal changes have been taking place for a very long time. That is not the reason for autoimmunity. It’s like the straw that broke the camel’s back, like I said. A woman will have other factors that are really the main triggers.
I want to talk about hypothyroidism/Hashimoto’s. I also want to talk about estrogen dominance because when talking about estrogen dominance, some women, as well as men, because men can have estrogen dominance, too. We tend to think of high estrogen. High estrogen definitely can mean estrogen dominance. You can also have low progesterone and normal estrogen levels. If someone has normal estrogen levels and low progesterone, this is also considered to be a state of estrogen dominance.
Symptoms associated with estrogen dominance, you can’t always go by symptoms, but you often can. If a woman who is cycling, she might experience PMS symptoms, breast tenderness, mood swings, heavier periods, weight gain, sleep disturbances. There could be overlap with Graves’ symptoms: anxiety, sleep issues, emotional volatility, Graves’ rage. Also overlap with Hashimoto’s, too. I’ll talk more about the overlap of symptoms shortly.
Let’s talk about hypothyroidism/Hashimoto’s and estrogen. When you have low thyroid, hypothyroidism, this also can contribute to estrogen imbalances. You might have slower hormone metabolism, which can result in reduced clearance of estrogen, as a result of potential estrogen accumulation. It could also lead to sluggish detoxification pathways. Detoxification is important to clear estrogen from the body as well as other hormones.
I spoke about the impact of hyperthyroidism on menstrual cycles. When you have low thyroid hormone, that could lead to heavier periods, longer cycles, irregular cycles. Sometimes, women with hypothyroidism might have shorter periods or skip periods, which are more common with hyperthyroidism. You can’t always go by the signs and symptoms.
I already mentioned estrogen’s role in autoimmunity. Too much estrogen isn’t a good thing; that could enhance the immune system response and potentially make someone more susceptible to autoimmunity. I’m honestly more concerned about xenoestrogens, which I’ll talk about.
If you have low estrogen, low estrogen is not a good thing. A lot of women as well as men get concerned about too much estrogen. You need estrogen to have a healthy immune response. If you have lower estrogen levels, that also could set the stage for Graves’. Once again, not the main reason. It’s combined with other factors.
If all you do is address estrogen, that probably won’t fix the problem. There are food choices you make. Chronic stress is definitely rampant these days. Environmental toxins and toxicants. Nutrient deficiencies. Gut health.
Speaking of gut health, that ties into the next topic I want to talk about, which is the gut-thyroid-estrogen connection. There is something called the estrobolome, which is essentially how gut bacteria influence estrogen metabolism. If you want the official definition, it’s the collection of gut bacteria and bacterial genes that help regulate the metabolism, detoxification, and recycling of estrogen within the body. In other words, the estrobolome is the part of the gut microbiome that influences estrogen levels.
After estrogen has been used by the body, I mentioned how you need to detoxify it. It has to be processed by the liver and eventually eliminated. The liver attaches compounds to estrogen in a process called conjugation. This helps prepare for excretion through the bowel and stool. Certain gut bacteria produce an enzyme called beta glucuronidase, which you can look at this enzyme on certain stool tests, like the GI Map or GI Effects. This enzyme can remove those attached compounds. This allows estrogen to be reactivated and reabsorbed into the bloodstream rather than being eliminated, which is not good.
To summarize, if you have elevated beta glucuronidase on a stool test, that is not good. That means that estrogen is probably being reabsorbed into the bloodstream and not being eliminated. This is what’s called enterohepatic recirculation. You don’t want to recirculate the estrogen; you want to excrete it.
What causes this increased beta glucuronidase activity? Typically, it’s imbalances in the gut microbiome, also known as dysbiosis. You need to heal the gut. You need to correct the dysbiosis. Typically, you will see those beta glucuronidase levels decrease over time. Something to think about.
This doesn’t mean every woman needs to get a GI Map or GI Effects. If you get a GI Map, a lot of times, practitioners are just focusing on H-pylori and parasites. These are important. Also, look at beta glucuronidase. Many times, beta glucuronidase looks okay. If I do a GI Map, and it looks okay, I won’t make a big deal out of it because it looks fine. If it’s elevated, or within the lab range but on the higher end, that is still something you want to pay attention to.
As far as some of the symptoms, like the overlap of symptoms when it comes to estrogen, perimenopause, menopause, and thyroid health, I covered some of these, but I focused more on hyperthyroidism. You can get brain fog, moreso with low thyroid, but also with perimenopause and menopause.
Fatigue is very common, moreso with hypothyroidism, but I do have a lot of people with hyperthyroidism who have fatigue because of the stress that hyperthyroidism is placing on the mitochondria. Fatigue is common with perimenopause and post-menopause. Not to say women who are cycling don’t experience fatigue. There are a lot of things that can affect fatigue, too. The adrenals can affect fatigue. Blood sugar imbalances.
Anxiety, which also is a symptom with these hormone imbalances. With hyperthyroidism, you can get anxiety.
Sleep disturbances. All these situations, hyper or hypo, perimenopause, post-menopause, even cycling women. A lot of people experience sleep disturbances.
Weight gain is very common with perimenopause and post-menopause as well as hypothryoidism. Weight loss is a more classic symptom of hyperthyroidism, but there are a lot of people with hyperthyroidism who have problems losing weight for other reasons. Not everybody with hyperthyroidism loses weight. I lost a lot of weight when I dealt with Graves’, but that’s not the case with everybody.
Hot flashes are common in perimenopause and post-menopause, as you get lower estrogen levels. With increased thyroid production, people with hyperthyroidism might experience what seem like hot flashes. Many times, it’s more like heat intolerance.
Let’s talk about testing for estrogen and other hormones. Most get these hormones tested in the blood. They usually test estradiol. You can also test estrone and estriol. You can do what’s called total estrogens. There are progesterone and testosterone, like total and free testosterone usually. Total and free testosterone is good to test in the blood. It’s not bad to look at estrogen and progesterone in the blood.
It really depends on the situation. If you have health insurance that will cover it, you might as well take a look at it. You can look at the pituitary hormones, FSH, LH and sex hormone binding globulin (SHBG). Blood is fine. I sometimes look at blood testing.
There is also dried urine testing, DUTCH testing. This looks at estrogen levels and progesterone levels and androgen levels, but it also looks at how you metabolize certain hormones. Estrogen metabolites, like 2OH, 2 hydroxy estrone, 4 hydroxy estrone, and 16 hydroxy estrone. You want mostly to have 2 hydroxy estrone. If you have too much 4 hydroxy and/or 16 hydroxy, that is not a good thing. You definitely want to support estrogen metabolism.
There could be numerous reasons for this. I mentioned beta glucuronidase and gut dysbiosis. There could also be genetics behind this. Someone might have what’s called poor methylation. I and many other people have what’s called MTHFR genetic variation. I have a C677T homozygous MTHFR, a genetic variation, and that could affect methylation, which also can affect estrogen metabolism.
DUTCH testing also looks at the circadian rhythm of cortisol and cortisol metabolism.
I used to do more testing for hormones in the saliva. Saliva will look at the free form of the hormones. If you are taking a progesterone cream, it might look okay on one of these other tests, especially a blood test.
The saliva looks at the free form of the hormone, so you might see really high levels of progesterone in the saliva. Not that that’s a good thing, but it’s definitely not as bad as seeing really high estrogen levels. Saliva has its place, too.
Some people will be able to afford any test I recommend, but it’s unreasonable to expect most people to look at two or three different tests for a hormone. Blood testing is usually more cost effective, especially if the person has health insurance. Definitely a time and place for DUTCH testing because you can’t look at estrogen metabolism in the blood or saliva.
Additional tests to consider are a thyroid panel, looking at TSH, free T4, free T3, maybe in some cases total thyroid hormones as well. There are antibodies for Graves’ and Hashimoto’s that I have discussed in other episodes.
Looking at liver markers. When looking at liver enzymes, like AST, ALT, GGT, GGT actually is a good marker that is overlooked. GGT, if it’s elevated, but even if it’s on the higher end, 40s, 50s, it could mean that you’re having issues with glutathione, which is the master antioxidant that is involved in detoxification. GGT is a valuable marker.
AST and ALT, if they are elevated, that typically means there is some liver damage taking place. You want to know that. Don’t get me wrong. I recommend a comprehensive metabolic panel that looks at the liver enzymes. It won’t tell you much about how you’re detoxifying.
There is a time and place for gut testing. GI Map, GI Effects. Those are the two I commonly recommend. There are others. Doctors Data has one. The Gut Zoomer by Vibrant Wellness. Not all stool tests will look at beta glucuronidase. Some of these stool panels look at the gut microbiome. For example, Viome is a more popular one that does not look at beta glucuronidase, I’m pretty sure. It’s a different type of test.
Blood sugar markers. Not only fasting glucose but insulin, hemoglobin A1C. I already spoke about the symptoms.
As far as supporting healthy estrogen balance, how do you do this? Gut health is very important. Addressing gut dysbiosis, imbalances in the gut flora. Having regular bowel movements is important. I should say “daily” because some people might think regular is every other day or even every third day. For some people, that’s their definition of regular. Really, you want daily bowel movements, at least one per day.
You might have to increase dietary fiber. I know not everybody can do that. Some people get gassy and bloating, which might suggest another gut issue, like SIBO. If you’re having issues with fiber, it doesn’t mean you need to eliminate fiber forever. You should figure out why you can’t tolerate fiber.
Liver function is important. You can do this through food. Eating fiber-rich vegetables are good. Cruciferous vegetables are good for gut health.
Adequate protein is important for a number of nutrients that are important for phase 2 detoxification. Protein is a macronutrient that is important for a lot of different things. Muscle mass, phase 2 detox, etc.
You want to minimize exposure to xenoestrogens. There are a number of those. I’ll talk more about those in a minute.
Hydration. Drinking plenty of water is important, too.
Managing chronic stress. There is an interaction between cortisol and estrogen. If you have high cortisol, if you’re stressed out, and cortisol is chronically elevated, that will decrease the sex hormones, progesterone. Decreasing progesterone is a relative estrogen dominance case. It also can decrease estrogen.
When you’re chronically stressed, that will decrease not only progesterone but DHEA, which is a precursor to testosterone. Testosterone converts into estradiol. If you have chronic stress for quite a long time, that could result in depletion of all these sex hormones.
Chronic stress can also have a negative effect on gut health. That could also affect estrogen metabolism. We spoke about beta glucuronidase. Estrogen also may influence HPA axis signaling, which is important when it comes to healthy adrenals and healthy cortisol production.
I can’t talk enough about blocking out time for stress management. You’re not going to eliminate the stressors, but you can do things to improve your perception of stress. Start out with five minutes per day. Get into the routine of stress handling. I have spoken about this many times. Definitely worth mentioning again here. Then you can gradually increase the duration over time.
Xenoestrogens, we need to keep in mind. There are microplastics, things like bisphenol-A (BPA), phthalates, pesticides, personal care products. All these endocrine disrupting chemicals can have negative effects on estrogen. Also, we’re all exposed to these microplastics, for example. That definitely will have a negative impact on estrogen metabolism.
We can’t get rid of these. All we can do is minimize our exposure to these, which is still important. I say “all you can do” in a negative way, but it is important to try to do as much as you can to support the liver, as I mentioned earlier.
There is a time and place for other interventions such as sauna. I do infrared sauna at least twice a week. Try to do it three days a week. Eating healthy foods, plenty of fiber-rich foods if you’re able to incorporate fiber. I am sure some people listening to this are following a carnivore diet or a keto diet. I know those could have benefits, especially carnivore, for autoimmunity.
There is some controversy as far as the need for fiber. When I say this, to me, it’s not controversial. The research shows that you need fiber. Carnivore proponents will dispute that. To me, it’s not controversial. You want to eat some plant-based foods. Not to say you don’t want to get enough protein, and you can’t get enough nutrients eating animal-based foods. For the health of the gut microbiome, I do think, and the research supports, that plant-based foods, fiber-rich foods are beneficial.
Supplements. You want to do as much as you can through diet and lifestyle. There is a time and place for supplements. DIM is very common for estrogen metabolism. You just need to be careful. I learned from Dr. Carrie Jones, who used to work for Precision Analytical Labs, the maker of the DUTCH test, that you don’t want to take DIM if your estrogen levels are low because it will further lower estrogen levels.
If someone has high estrogen metabolites on the DUTCH test, like high 4 hydroxy and/or 16 hydroxy, and they have low estrogen levels, you don’t want to take DIM. If their estrogen levels are okay, it’s okay to take DIM.
If your estrogen levesl are low, she recommends taking sulforaphane, which you can get from cruciferous vegetables, too. Broccoli, broccoli sprouts, etc. She discusses in one of her videos how you would have to eat a lot of broccoli or broccoli sprouts. You won’t do it through diet alone initially. Maybe to maintain healthy estrogen levels. But you probably need supplementation if you have elevated 4 hydroxy or 16 hydroxy levels.
Calcium D-glucarate is commonly given, especially if someone has elevated beta glucuronidase levels. There are other supplements. Magnesium is beneficial. Those three, DIM, sulforaphane, and calcium D-glucarate, are very commonly recommended for helping with estrogen metabolism. Doesn’t mean you should take all three of those. Usually, if I recommend any, it’s one. I don’t recommend these to everyone.
Some takeaways. Estrogen and thyroid hormones have a two-way relationship. Both hyper and hypothyroidism can influence estrogen balance. I mentioned how estrogen affects TBG, which can influence the availability of thyroid hormone. Gut health also plays a major role in estrogen metabolism. I spoke about beta glucuronidase, which you can test for on certain comprehensive stool panels. Hormonal transitions such as pregnancy, post-partum, perimenopause, menopause, that could impact thyroid health or autoimmunity through its influence of estrogen and progesterone. Keep in mind there are usually other factors as well.
Thank you as usual for tuning in. Hope you found this episode to be valuable. Look forward to catching you in the next one.