Estradiol is the predominant, and the most potent, circulating estrogen. Bioavailable estradiol, which represents about 2% of the total protein-bound estradiol in the bloodstream , exits the bloodstream in capillary beds and enters target cells such as the brain, breasts, uterus, bone and heart. There, it binds to the estrogen receptors and activates an estimated 250+ genes that induce the synthesis of enzymes and other functional proteins involved in regulating a multitude of actions, including neurotransmitter synthesis and action in the brain, and activation of cell growth and proliferation and synthesis of progesterone receptors in the estrogen/progesterone target tissues that allows for subsequent counter-response to the growth promoting actions of estrogens.
If symptoms of estrogen imbalance are problematic this may be due to other hormonal imbalances with a symptom profile similar to low or high estradiol (e.g. low progesterone, low testosterone, low or high cortisol, low thyroid).
Estradiol [Premenopausal (Luteal)]
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