Effects of Estrogen Dominance

Estrogen is one of the primary female sex hormones. Normally, estrogen is in balance with the other primary sex hormone, progesterone. When the body has too much estrogen, from overproduction of estrogen or lack of progesterone, it enters a state referred to as "estrogen dominance." Estrogen dominance can result from excess estrogen production within the body, HRT (hormone replacement therapy) common in menopause, a drop in progesterone production or intake of excess estrogen from environmental sources, such as meat injected with hormones or man-made chemicals the body confuses with estrogen. Whatever the reason, estrogen dominance can have serious consequences on the body, producing unwanted side effects.

Estrogen and hormone books. Credit: designer491/iStock/Getty Images

Weight Gain

Weight gain is a serious effect of estrogen dominance. Not only does it make us uncomfortable with ourselves physically, excess weight increases the risk for heart disease and diabetes. A study reported in the "Journal of Clinical Endocrinology and Metabolism" states that fat tissue produces excess hormones such as estrogen, particularly in abdominal tissue. As fatty tissue produces estrogen, estrogen produces more fatty tissue and results in a continuous cycle.

Increased Cancer Risk

Studies published by the American Cancer Society state that estrogen can raise the risk of developing cancers, such as breast and ovarian cancer, and can actually increase breast tumor growth. These tumors are composed of cells with many estrogen receptors. Their warnings are especially geared to estrogen dominance as a result of estrogen replacement therapy.


Estrogen dominance can cause many conditions that affect fertility. The hormonal imbalance between estrogen and progesterone can create polycystic ovaries. According to Dr. Michael Lam, a specialist in hormone balancing and author of "Estrogen Dominance," when a follicle releases an egg from the ovary, it causes a surge in progesterone. If the egg is produced but not released, it can become a cyst. Without the surge of progesterone, the brain tells the ovaries to increase estrogen and release more eggs. If these eggs are not released, they too develop into cysts. PCOS (poly-cystic ovarian syndrome) disrupts a woman's ovulation cycle, decreasing the chances of conception.

More Side Effects

Weight gain, increased cancer risk and infertility are just a few side effects of estrogen dominance. Dr. John Lee, who coined the phrase "estrogen dominance," did extensive study in the field of this hormone imbalance. What he found were numerous health conditions that were a result of excess estrogen. These include allergies, memory loss, early puberty in children, gall bladder disease, irritability and mood swings, headaches, fatigue and osteoporosis. In men, there was an increased risk of prostate cancer. Estrogen dominance is not limited to women. Men can also have an increase of estrogen through environmental sources.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.
Load Comments

Copyright © 2019 Leaf Group Ltd. Use of this web site constitutes acceptance of the LIVESTRONG.COM Terms of Use , Privacy Policy and Copyright Policy . The material appearing on LIVESTRONG.COM is for educational use only. It should not be used as a substitute for professional medical advice, diagnosis or treatment. LIVESTRONG is a registered trademark of the LIVESTRONG Foundation. The LIVESTRONG Foundation and LIVESTRONG.COM do not endorse any of the products or services that are advertised on the web site. Moreover, we do not select every advertiser or advertisement that appears on the web site-many of the advertisements are served by third party advertising companies.