Estrogen Dominance

What is Estrogen Dominance?

Estrogen dominance is a common condition of estrogen excess, when unopposed or not balanced with progesterone.  Many undesirable effects are a result of estrogen dominance and often occur at pre and post menopause, with oral contraceptives, not ovulating, exposure to synthetic estrogens, with conventional hormone replacement therapy, and after hysterectomy.  Estrogen dominance is a term coined by John Lee, M.D. in the book What Your Doctor May Not Tell You About Menopause, which you may find a good resource.

Scientific studies link high estrogen or estrogen imbalance with a wide range of symptoms and conditions, from hot flashes, night sweats, low libido, and foggy thinking to more serious conditions related to reproductive health (endometriosis and Polycystic Ovary Syndrome, PCOS) as well as breast disease, including cancer. Hormone imbalances triggered by medications like synthetic hormone combinations have also been found to contribute to estrogen dominance problems.

Symptoms of estrogen dominance include:

Causes of Estrogen Dominance

  • Premenopause:

Lack of ovulation and/or reduction of ovarian production of progesterone, and use of synthetic hormones, like oral contraceptives.

  • Perimenopause (40s-mid-50s):

Lack of ovulation or erratic cycles, when estrogen levels fluctuate rapidly from high to low in the absence of adequate progesterone, and use of synthetic hormones, like oral contraceptives.

  • Postmenopause:

An imbalance of estrogen to progesterone ratio in waning reproductive years when ovarian production of estrogen can decline by as much as 60% and levels of progesterone can drop to nearly zero with the cessation of ovulation.

  • Hidden sources:

These include shampoos and conditioners with placental extracts, cosmetics, and meat, like beef, chicken and pork that have been fattened up quickly with hormones.

Balancing Estrogen

Women of all ages benefit from balanced hormones.  With menstrual irregularities, PMS, endometriosis and infertility, testing can be helpful in understanding the underlying condition.  Health care providers working with peri-menopausal and menopausal women find hormone testing to be a key step in detecting and correcting imbalances. Testing hormone levels is also invaluable for monitoring women using hormone replacement therapy.

Why Test Hormones

Saliva and/or blood spot testing is a simple, reliable means for determining estrogen dominance. The test measures bioavailable levels, those hormones actively working in the cells of the body.  This “bioavailable” measurement can detect long-hidden hormone imbalances and more closely correlates with personal symptoms.  Because hormones work together to create a balanced internal milieu, it makes sense to test all of the following to help determine estrogen dominance:

  • Estradiol (E2) the most potent of the estrogens
  • Progesterone (Pg)
  • Testosterone
  • Cortisol (stress hormones for adrenal function)
  • Thyroid Profile (TSH, T3, T4, TPO Antibodies for Hashimoto’s Thyroiditis)


ZRT Laboratory compares symptoms with or without hormone usage and relates these back to tested hormone levels providing more information than is available with standard lab results.  In this way, comprehensive hormone testing can assist detection of previously undiagnosed disorders, and serve as a rational basis for treatment to relieve symptoms and restore hormone balance.


There are a number of good references designed to help you to understand the changes and/or symptoms you may be experiencing.  We encourage you to read and educate yourself so that you and others around you may better understand these changes.
What Your Doctor May Not Tell You About Menopause.  John R. Lee, M.D.
The Miracle of Natural Hormones. David Brownstein, M.D.
When Your Hormones Go Haywire.  Pamela Smith, R.D.