Estrogen, the most well-known female sex hormone, is an important part of every person’s body. It is a formative part of the development and regulation of the female reproductive system and helps to regulate cognitive, bone, and cardiovascular health in both men and women (1, 2). However, a wave of hormonal dysfunction called "estrogen dominance” has been affecting a number of women (and even some men). Premenstrual syndrome (PMS), endometriosis, fibroids, and even mood disorders have all been linked to estrogen dominance.
What is estrogen dominance?
Estrogen dominance is a term for a higher-than-normal level of estrogen in comparison to other sex hormones in the body, which can mean either an abundance of estrogen in the body or a lack of other hormones (4). While men generally have a set amount of estrogen that does not waver much and estrogen dominance is relatively rare, they may still experience estrogen dominance due to environmental and genetic factors (5).
Women of reproductive age experience cycling hormones during the menstrual cycle. During the two phases (follicular and luteal), estrogen levels vary greatly (6). The follicular phase (first day of the menstrual period through ovulation) lasts about 14 days, though it may be longer. Estrogen levels steadily rise through this phase, peaking just before ovulation (6). At this point, the body enters the luteal phase, during which estrogen should dip and progesterone rises and peaks. Estrogen should peak again (though much less than in the follicular phase), both hormones should reduce greatly to a baseline, menstruation occurs, and the cycle begins again (6). However, estrogen may begin to dominate other hormones, leading either to too much estrogen or too little progesterone, etc. This may occur due to a number of factors, including increased production of estrogen, altered estrogen metabolism and expulsion from the body, or decreased progesterone production (4).
What are the symptoms of estrogen dominance?
There are many hormonal conditions and disorders that have estrogen dominance at the root of their development, including fibroids, increased or severe PMS, endometriosis, and mood disorders, which will be discussed at length below. However, those who do not develop disorders but still have estrogen dominance may still experience a wide range of unpleasant symptoms. While these symptoms vary greatly, the most common include (2, 13):
Swollen or tender breasts
Irregular periods, spotting, heavy bleeding
General fatigue or sleepiness
Cold hands or feet
Memory problems or “Brain Fog”
The most common symptoms in men include infertility, breast tissue growth, and erectile dysfunction (2). It can also put you at higher risk for thyroid diseases, blood clots, heart attack and stroke, and breast or ovarian cancer (13).
What are the risk factors for estrogen dominance?
Unfortunately, there are many factors at play in our modern life that put us at risk for estrogen dominance. The first is the astonishing number of xenoestrogens that we are all exposed to on a daily basis. Xenoestrogens are multiple classes of compounds that mimic estrogen but are not naturally part of our body (6). These compounds can be broken into two types: phytoestrogens and endocrine-disrupting chemicals (EDCs).
Phytoestrogens may offer some benefit to cardiovascular, reproductive, cognitive, and mood processes, though this is still being studied (6, 7). These may even help promote a specific type of beneficial estrogen that supports hormone balance (2-hydroxyestrone) and reduce a more harmful type (16-hydroxyestrone). For many, phytoestrogens are a part of maintaining a healthy diet, as the most common sources include soy, berries, seeds, grains, nuts, cruciferous vegetables (broccoli, cauliflower, etc.), mango, and herbs (6). Endocrine-disrupting chemicals are another class of xenoestrogens that are incredibly harmful and unfortunately, just as common in our daily life. The most well-known EDCs include BPA, BHA, parabens, and pesticides (6). These find their way into our bodies through many sources, including plastics, personal care products, fragrances, water, nearly all food (pesticides, leaching from food packaging, contaminated water used during agricultural processes, etc.), hormonal birth control, and even the thermal paper that is used for receipts (6). Everyone has long-term low-level exposure to endocrine-disrupting chemicals, which may lead to estrogen dominance in some people (6). High levels of stress are another potential factor for estrogen dominance. Cortisol is our main stress response hormone and it shares the same precursors (or building blocks) that progesterone does (4). So, when we are chronically stressed and our bodies make too much cortisol, it doesn’t leave enough of those building blocks for the body to make enough progesterone (4). So, while estrogen levels may not be abnormally high in this instance, the distinct lack of progesterone may still cause imbalance and dominating estrogen. Poor gut and liver health is another contributor to estrogen dominance. The liver works to remove excess estrogen from the body via the digestive system (4). If it is not working properly due to an overload of toxins, alcohol damage, disease, or other factors, it may slow down this process (4, 13). Additionally, if the gut is unbalanced and has an overgrowth of certain bacteria, it may allow for an increase in an enzyme called beta-glucuronidase. This enzyme allows estrogen to be freed from the digestive system and return back to the body, increasing estrogen levels (4).
How is estrogen dominance the cause of PMS, endometriosis, fibroids, and mood disorders? Don’t those conditions have other causes, too?
While all of these conditions can stem from a number of factors, each has also been linked to estrogen dominance. Because each woman’s lifestyle, menstrual symptoms, and monthly cycle vary so much, there is not one set cause of PMS that has been determined. However, many studies have proposed the hypothesis that PMS symptoms are triggered by the estrogen peak occurring just before ovulation, especially given that introducing estrogen at other points in the cycle has provoked PMS-like symptoms (8). This hypothesis can hold up even for women whose estrogen levels are within normal ranges because it is not necessarily the amount of estrogen itself that causes the symptoms, but the act of peaking (8, 9). Drastic fluctuations in hormones that are unbalanced (i.e., a peak of estrogen without a coinciding/balancing peak of progesterone) are one of the most well-known triggers of the dysfunctions and disorders mentioned in this article (8, 9, 10, 11, 12). This is what is suspected to be the case behind uterine fibroids as well. Because fibroids, the most common kind of gynecologic tumor, are estrogen-dependent, by and large, only women of reproductive age develop them (12). However, it is not the estrogen alone that causes their growth, but rather the levels of progesterone and other factors in tandem with existing estrogen that promote fibroid growth (12).
Endometriosis is the growth of endometrial-like tissue (which lines the inside of the uterus) outside the uterus, and it is also dependent on estrogen (9). This is another of the most common gynecological diseases, affecting up to 10% of the population of women of reproductive age, and drastically affecting fertility (9). Both high estrogen levels and hormonal fluctuations are considered the main causes of endometriosis, though inflammation may play a role too (9). Interestingly, some researchers believe that being exposed to high levels of estrogen in utero may be the initial cause of endometriosis, potentially leading to physical differences that put those affected at a higher risk of developing endometriosis (6). All three of these can create a positive feedback cycle, leading to more estrogen, greater fluctuations, and more painful symptoms (9).
Lastly, mood disorders such as anxiety and depression are also linked to estrogen. Estrogen is capable of modifying neurotransmitters and other neural structures, and may even exhibit some neuroprotective capabilities (11). However, drastic fluctuations can lead to a reduced capacity for mood regulation, leading to mood disorders (11). Excess estrogen has also been linked to depressive symptoms, even in men (13).
How can I fix estrogen dominance?
Functional medicine can provide some of the best avenues and answers to help combat estrogen dominance and bring your hormones back into balance. Before determining any treatments, our functional physicians will meet with you to understand your whole health history and ask about any conditions, medications, and symptoms you are experiencing. There are a large number of tests that can be helpful to pinpoint exactly what is happening in your body to test hormone levels, thyroid function, gut health, liver function, and more. Once we have determined what you need, we can create a treatment plan together. Some of the more common treatment options for estrogen dominance (and the disorders mentioned above) that work toward total-body health include (4, 13):
Exercise and, if relevant, weight loss to regulate sex hormones and cortisol levels
Implementing relaxation and rest practices to lower stress levels
Dietary changes or addition of probiotics or enzymes to heal gut microbiome and balance enzyme levels
Supplements or diet changes to improve liver function and promote better estrogen expulsion
Supporting thyroid and adrenal function via supplements or diet modification
Increasing water intake
Adding certain phytoestrogenic foods into your diet, including cruciferous veggies, berries, some root vegetables, healthy Omega-3 fats, and even dark chocolate
Improving sleep quality and quantity
If you feel that your hormone levels may not be balanced, please reach out! No one should have to suffer from all of the many painful, inconvenient, and uncomfortable symptoms that estrogen dominance and hormonal imbalance may cause. We would love to partner with you to help you achieve better balance and health.
Jonathan Vellinga, MD is an Internal Medicine practitioner with a broad interest in medicine. He graduated Summa cum laude from Weber State University in Clinical Laboratory Sciences and completed his medical degree from the Medical College of Wisconsin.
Upon graduation from medical school, he completed his Internal Medicine residency at the University of Michigan. Dr. Vellinga is board-certified with the American Board of Internal Medicine and a member of the Institute for Functional Medicine.
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