Components of Estrogen

Estrogen is a group of important hormones, chemical messengers, that regulate the female reproductive system from sexual development throughout the reproductive years. Most of the estrogen produced by a woman's body is made in the ovaries, but small amounts are secreted by the adrenal glands and placenta. Estrogen levels can be affected by disease, by childbirth and by menopause. Estrogen is not one hormone, however, but has three different components.

Estrone

• One component of estrogen is called estrone. According to the WebMD, it is widespread throughout the body and the only estrogen component found in any significant amount after menopause. It is mainly produced by the ovaries before menopause and by the adrenal glands after menopause. During the reproductive years, the other components of estrogen, estradiol and estriol, predominate, but at menopause, estrone levels rise significantly and the two others diminish. Estrone is given by injection to relieve symptoms of menopause and for those women with hormone imbalances or problems with ovaries. It is also sometimes prescribed for men or women with prostate cancers or breast cancers.

Estradiol

• Estradiol is the primary source of estrogen for women during the childbearing years. The estradiol component regulates female characteristics, the menstrual cycle and sexual function. It also support bone growth. Developing ovary follicles produce estradiol in the body. After menopause, estradoil levels drop and the estrone is the predominant estrogen component. Estradiol is used to treat severe symptoms of menopause such as hot flashes, nightsweats, vaginal dryness and osteoporosis. According to Drugs.com, it should not be prescribed to women who are pregnant as it can harm the fetus or cause birth defects. Estradiol is sometimes used to as part of cancer treatment in both women and men. Taking hormones can cause blood clots, stroke or heart attack and should not be taken by those with high risk factors such as diabetes, high blood pressure, high cholesterol, high triglycerides or those who smoke.

Estriol

• Estriol in an estrogen compound produced in large amounts by the placenta during pregnancy. It is a weak estrogen that is thought to have anti-cancer effects. Of the three components of estrogen estrone and estradiol are thought to have a tendency to increase cancer growth, while estriol is thought to be less carcinogenic, according to Aeron.com. Estriol is produced almost exclusively during pregnancy and progressively rises to a peak in the late gestational period. When used for menopause symptom relief, it does not cause endometrial proliferation to the same extent as the other estrogens. Topical estriol is used for genital atrophic changes and urinary incontinence in menopausal women.