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Health Topics

Risks and Side Effects of Hormone Therapy

While HT helps many women get through menopause, and relieves many painful symptoms, as with most health treatments, there are risks. In general, for MOST women the benefits outweigh the risks. According to the Women’s Health Initiative (WHI) study, known health risks for HT include:

  • An increased risk of endometrial cancer (if a woman still has her uterus and is not taking progesterone/progestin along with estrogen)
  • An increased risk of blood clots and increased risk of stroke in older women, particularly with higher oral doses in women over age 65
  • An increased risk of breast cancer diagnosis in women taking estrogen-progestin combination therapy for extended periods of time. Estrogen alone, however, was not shown to increase the risk of breast cancer, in fact LOWERED breast cancer risk.
  • An increased risk of heart disease in women taking long-term estrogen-progestin combination therapy in women who start combination HT 10 or MORE years after menopause. Estrogen alone has not been shown to increase the risk of heart disease in the estrogen-alone arm of the study and both women on estrogen or estrogen-progestin who started on HT within 10 years of menopause had a REDUCED risk of death and reduced risk of heart disease. So, timing is key.

Based on the WHI Study Results, Should I Stop Taking HT?

It's important that you do not make any abrupt changes to your HT without consulting your doctor. He or she can discuss with you the benefits and risks of HT based on your individual circumstances and hormone status.

The National Heart, Lung and Blood Institute (NHLBI), which sponsored the study in collaboration with other units of the National Institutes of Health (NIH), has the following recommendations for women who may have questions about the long-term use of HT:

  1. First, the therapy should not be continued or started solely to prevent heart disease. Women should consult their doctor about other methods of prevention.
  2. Second, for osteoporosis prevention, women should consult their doctor and weigh the benefits against their personal risks for heart attack, stroke, blood clots and breast cancer.
  3. Third, women should keep up with their regular schedule of mammograms every 1-2 years.
  4. Finally, while short-term use was not studied, women taking the therapy for relief of menopausal symptoms. The benefits certainly outweigh the risks.

What Are the Side Effects of HT?

Adjusting either the dosage or the form of the medication you are taking can often reduce side effects of HT. Talk to your doctor if you think your dosage needs to be adjusted.

The most common side effects are:

  • Monthly bleeding
  • Irregular spotting
  • Breast tenderness

Less common side effects of hormone therapy include:

  • Blood clots and stroke (rare, but the most serious risk)
  • Fluid retention
  • Headaches
  • Dizziness
  • Skin discoloration
  • Increased breast density
  • Skin irritation under estrogen patch

Who Shouldn't Take Hormone Therapy?

HT is not usually recommended for women who have:

  • Active or past breast cancer
  • Recurrent or active endometrial cancer
  • Abnormal vaginal bleeding
  • Recurrent or active blood clots
  • History of stroke
  • Liver disease
  • Known or suspected pregnancy

For more information on menopause, download the Free Guide to Managing Menopause.