What Does Estrogen Do?

Medically Reviewed By William C. Lloyd III, MD, FACS
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Most people know estrogen is the primary group of hormones that affect sexual and reproductive development in females. However, estrogen actually affects many components throughout the body, so it’s important to know how estrogen works, what happens when there’s too little or too much, and how estrogen replacement can cause side effects.

Estrogen hormones affect sexual and reproductive development.

Usually mistaken as a single element, estrogen is actually a group of hormones that work together in the female body for sexual and reproductive development. There are three main types of estrogen: estriol, estradiol and estrone. While the ovaries produce most of these estrogen hormones, the adrenal glands (atop each kidney) and even fat cells produce estrogen, although those amounts are small. Estrogen is dispersed throughout the body via the blood, allowing it to reach a variety of components.

Estrogen brings about many changes for females during puberty. 

As a key component in the female’s sexual and reproductive development, estrogen regulates the menstrual cycle, spurs pubic and underarm hair growth, and stimulates breast growth. Estrogen also plays a role in the musculoskeletal and cardiovascular systems as well as the brain. It protects bone health and keeps cholesterol under control. Plus, estrogen affects the development of several body components including the pelvic muscles, the urinary tract, the reproductive tract, the breasts, heart and blood vessels, mucous membranes, bones, skin, and hair.

Too much estrogen could result in weight gain and menstrual problems. 

Estrogen production is tightly regulated and estrogen levels fluctuate throughout the month as your menstrual cycle occurs. Typically, estrogen levels peak in the middle of the menstrual cycle; however, if these levels remain consistently high, it could indicate a serious issue. Too much estrogen could disrupt your menstrual cycle, increase premenstrual syndrome, lead to weight gain, make your feel depressed or anxious, reduce your sex drive, lead to excess fatigue, and produce fibrocystic lumps in the breast and/or fibroids in the uterus.

Too little estrogen typically occurs during menopause. 

For most women, their estrogen levels drop dramatically during menopause. Some women also experience a drop in estrogen after their ovaries are removed, such as from ovarian cancer surgery. If estrogen levels remain low, women could experience disrupted menstrual periods, hot flashes, night sweats, dryness and thinning of the vagina, reduced sexual desire, difficulty sleeping, fatigue, dry skin, and mood swings. Low estrogen also may cause a bad headache before the onset of the menstrual period. Severe risks of low estrogen include osteoporosis and heart disease.

Estrogen replacement can be beneficial, especially during menopause. 

Once the body enters menopause and estrogen production is greatly reduced, symptoms of menopause prompt some women to start hormone replacement therapy (HRT). Balancing hormone levels may give your body an estrogen boost and reduce the symptoms of menopause, such as hot flashes and vaginal dryness. Oftentimes, this will be a medicine containing estrogen or both estrogen and progesterone, which is another hormone the ovaries produce. However, HRT is not necessarily required just because you start menopause. If you have reached menopause, talk with your doctor about the pros and cons of estrogen replacement therapy, based on your personal circumstances and health history.

Estrogen side effects can be serious. 

Many women start estrogen replacement therapy to alleviate menopause symptoms or to help prevent osteoporosis, or both. Estrogen is also a treatment option for delayed onset of puberty. However, it’s important to monitor how HRT affects your body. HRT may increase the risk of developing certain health conditions. These include a higher risk of heart disease, blood clots in the legs or lungs, stroke, and breast cancer. Ideally, any HRT regimen would be in the lowest possible dose for a short period of time. That’s why it’s important to speak with your doctor before starting any HRT program.

Estrogen in men is necessary for good health.

Although men need less estrogen than women, the hormone still plays an important role in the male body. For instance, it is crucial to the development and function of the male reproductive organs, and it also protects bone health. If men have excess levels of estrogen, they may experience poor erections, infertility, and enlarged breasts. If their estrogen levels drop too low, they could have excess belly fat and a reduced sexual desire. Men with too much or too little estrogen should talk with their doctor to see if estrogen therapy is needed; it is an uncommon treatment.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 May 12
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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