Taking estrogen can be important for some people, but does it cause weight gain?

Estrogen has a host of important health benefits. The sex hormone plays a critical role in reproductive health, sexual development, muscle development, and bone strength. In women, it also helps with menstrual cycle regulation and benefits the urinary tract, reproductive tract and breast tissue. 

Though estrogen is produced naturally in the body, some people seek to increase estrogen levels by improving their diet, getting more vitamins and minerals, or by taking natural estrogen supplements. Other times, doctors recommend estrogen hormone therapy. "At the time of menopause, when menstrual cycles end, some women elect to take a small dose of estrogen therapy to reduce symptoms such as hot flashes, sleep and mood disruption and vaginal dryness," explains Cynthia Stuenkel, MD, a clinical professor of medicine at UC San Diego School of Medicine. 

Such therapy comes with some risks, however, that the experts say people need to be aware of. 

Can you take estrogen supplements? 

While a natural first step to increase estrogen levels is improving one's diet by eating more grains, fruits, vegetables and soy products, some people also use supplements to improve estrogen levels. Though supporting research is limited, supplements such as red clover, black cohosh and DHEA are all believed to be helpful. 

Other people take vitamins and minerals known to help the body produce and use estrogen more effectively. These include vitamin E, vitamin B, vitaminD, and the mineral boron. 

Though such vitamins and minerals are considered safe when taken within recommended limits, it's important to note that the U.S. Food and Drug Administration (FDA) does not regulate supplements the same way it regulates food and drugs, so it's recommended to consult with a registered dietician or primary care physician before taking estrogen supplements. 

What is estrogen hormone therapy? 

For people with especially low estrogen levels or for women experiencing menopause, hormone therapy may also be prescribed. It can be administered topically through a cream or patch, taken orally as a pill or tablet or implanted under local anesthetic. 

Though estrogen hormone therapy used to be routinely recommended, some large clinical trials showed health risks associated with it including breast cancer, blood clots and heart disease, so it is now recommended less often, according to Mayo Clinic. 

Certain people still benefit from hormone therapy, however, and individual conditions, health history, and one's age are all known to affect risk. "Estrogen should be prescribed by a physician who has knowledge and experience of potential risks," advises Andrew Greenberg, MD, director of the obesity and metabolism lab at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. He adds that if such risks aren't determined and if not given in the proper setting, "hormone therapy may promote certain detrimental health effects." 

What's more, Stuenkel notes that estrogen hormone therapy "is not currently approved for prevention of chronic disorders related to aging" the way some people think it is, "though the FDA allows that prevention of bone loss can be a reason to choose estrogen therapy in women at risk if other bone strengthening agents are not appropriate." 

Does estrogen cause weight gain?

One of the side effects or risks some people worry about when taking estrogen is whether it contributes to weight gain. "Contrary to popular thought, estrogen in combined oral contraceptives and postmenopausal therapy preparations does not cause weight gain," Stuenkel reassures. She notes that in several randomized clinical trials, when estrogen was compared with placebo (non-medication) treatment, "estrogen therapy did not increase weight." 

It's important to note, however, that in most such cases, estrogen was used to restore or improve estrogen levels. Because estrogen (and testosterone) do impact where and how the body stores fat, "excess estrogen could cause weight gain in females, particularly in the waist, hips and thighs," says Disha Narang, MD, an endocrinologist at Northwestern Medicine Lake Forest Hospital. "Estrogen levels are also often elevated in people with increased body fat and during the first half of pregnancy," she adds. 

On the other side, Greenberg notes that decreased levels of estrogen associated with women entering menopause have also been linked to weight gain. 

In other words, balance is key. Too much or too little estrogen can affect one's weight, the experts say, so consulting with one's primary care physician is important to determine current estrogen levels and whether supplementation or hormone therapy could be helpful. 

More:Estrogen is one of two major sex hormones in females. Here's why it matters.