The Estrogen Hormone

Estrogen is the most popular hormone of the 5 main hormones. It’s the most talked about, most referred to and commonly mistaken as a female hormone, when in fact it is found in males too. Estrogen is responsible for the growth and development of female sexual characteristics and reproduction. Produced in the ovaries, adrenal glands and fat tissues, estrogen travels through bloodstream and binds to estrogen receptors on cells in targeted tissues, affecting the breasts, uterus, brain, bone, liver, heart and other organs as well. Though there is much known about estrogen in females, not much is known about it males.

Estrogen is produced in high quantities right before ovulation and it also helps the uterus in rebuilding its lining after menstruation. It also acts as a “feedback” control on the brain hormones LH and FSH. So in other words, the two sex hormones estrogen and progesterone travel up to the brain to either increase or decrease the amount of LH and FSH being produced. The feedback helps to regulate timing and events of the menstrual cycle.

Types of Estrogen

There are three types of estrogen, Estrone, Estradiol and Estriol that control the growth of the uterine lining during the first part of a woman’s menstrual cycle, cause changes in the breasts during adolescence and pregnancy and regulate many processes such as bone growth and cholesterol levels. Here is a brief description of each:

• Estrone is produced mainly in the ovaries of premenopausal women.
• Estradiol is produced mainly in the ovaries of premenopausal women.
• Estriol is produced by the placenta during pregnancy.

Estrogen During Pregnancy

During a woman’s reproductive years, the pituitary gland in the brain generates hormones that cause a new egg to be released from its follicle each month. As this follicle develops, it produces estrogen, which causes the lining of the uterus to thicken. Working with progesterone, if fertilization occurs, estrogen prevents any further ovulation cycles from happening throughout the course of the pregnancy. If fertilization does not occur, estrogen levels drop sharply.