Estrogen dominance is the condition of increased estrogen levels relative to progesterone levels in the body. Estrogen dominance may be the result of overproduction of estrogen by the body, changes in estrogen metabolism and excretion, or an imbalance in the estrogen to progesterone ratio. Many conditions are thought to be associated with or exacerbated by estrogen dominance, including breast and uterine cancers, fibroids, endometriosis, and polycystic ovarian syndrome.

The body makes three main estrogens:

·         Estrone (E1)

·         Estradiol (E2)

·         Estriol (E3)

Estrone (E1) is the main type of estrogen present in the body after menopause, made primarily in adipose tissue. Estradiol (E2) is the strongest estrogen, made by the ovaries and present in the body before menopause. Estriol (E3) is the weakest estrogen, present in the body primarily during pregnancy.

The body has two main receptors to which estrogen binds: alpha receptors that promote cell growth and beta receptors that inhibit cell growth.  Each type of estrogen binds with varying affinity to these receptors, resulting in either cell proliferation or cell inhibition.  Besides the direct effects of estrogen in the body, its metabolites are also important.