The risks of HRT differ depending on the health status of the woman taking it, and on the type of HRT.
Risks for healthy menopausal and post-menopausal women
The NIH conducted the Women's Health Initiative (WHI) trial to learn about the risks and benefits of continuous estrogen+progestin HRT for post-menopausal women.
- In one arm of this trial, researchers found that healthy post-menopausal women who took the therapy were at increased risk of invasive breast cancer, coronary heart disease, stroke, and blood clots. There were also benefits of estrogen plus progestin, including fewer cases of hip fractures and colon cancer.
- Because the harm of HRT for healthy post-menopausal women in this trial was greater than the benefit, the researchers stopped the trial.
- In light of the findings, the U.S. Food and Drug Administration noted that even though HRT effectively lessened some menopause symptoms in healthy post-menopausal women, it carried serious risks. Women should discuss the potential benefits and risks of HRT with their health care provider. The FDA recommends HRT for post-menopausal women be at the lowest doses for the shortest amount of time to reach treatment goals.
- For more information about the WHI and its findings on post-menopausal HRT, visit http://www.nhlbi.nih.gov/whi.
Risks of HRT for pre-menopausal women with certain health conditions
Women whose bodies have stopped making estrogen or don’t make enough estrogen often take HRT to reduce symptoms and maintain overall health.
- For instance, low estrogen levels in women with premature ovarian failure put these women at risk for osteoporosis and heart disease. HRT helps maintain bone health and reduce the risk of heart disease.
- In these cases, HRT is actually replacing hormones that the women’s bodies should be making—hormones that they need for their overall health.
- HRT taken by women with certain health conditions is different than that taken my post-menopausal women. The risks associated with post-menopausal HRT do not apply to pre-menopausal women taking HRT.