Estradiol is the most powerful estrogen of a group of endogenous estrogen steroids, which includes estrone and estriol. In women estradiol is responsible for growth of the breast and reproductive epithelia, maturation of long bones and growth of the secondary sexual characteristics. Ethinyle Estradiol is produced primarily by the ovaries with secondary production by the adrenal glands and conversion of steroid precursors into estrogens in fat tissue.

During the early part of the menstrual cycle, estradiol levels remain constant. This is followed by a rapid increase reaching a peak the day before or the day of the Leutinizing Hormone surge. It is generally believed that the rise in estradiol is the factor, which causes LH release. Following ovulation there is a drop in estradiol followed by a second rise, which corresponds with the development of the corpus luteum.

Normal estradiol levels are used to assess fertility, amenorrhea and puberty in girls. Measurement of estrogen levels is also useful to monitor and titrate replacement therapy particularly when the endpoints are long-term health rather than the immediate relief of symptoms. If the amount of estradiol compared to testosterone increases, then men can see certain symptoms such as weight gain especially in the midsection, development of enlarged breasts (gynecomastia), decreased sex drive, and many of the signs of low testosterone

Side Effects of Estradiol

Side effects that usually do not require medical attention but if they are bothering consult your physician: change in sexual desire, mild stomach upset, mood changes, anxiety, depression, frustration, anger, or emotional outbursts, increased or decreased appetite, skin rash, acne, or brown spots on the face, tiredness, vaginal yeast infection (irritation and white discharge) and weight gain.