Contemporary hormone replacement therapy (HRT) was not associated with an increased risk of heart attack, stroke, blood clots or death among women ages 45 to 59, according to a large, long-term study of more than 52,000 women in Israel. The findings from this independent, preliminary research will be presented at the American Heart Association’s Scientific Sessions 2026. The meeting is Nov. 6–9 in Chicago.
“Concerns that hormone replacement therapy may affect the heart are one of the most common reasons women decline hormone therapy to manage menopause symptoms, and why some health care professionals may hesitate to offer it,” said lead study researcher Ronen Arbel, Ph.D., a researcher in the community medical services division of Clalit Health Services in Tel Aviv, Israel, and a researcher with Sapir College’s Maximizing Health Outcomes Research Lab in Sderot, Israel.
Previous randomized trials found associations between HRT and cardiovascular harm. However, results were mixed, and much of that evidence came from studies involving older HRT formulations that are no longer commonly used, higher doses and women who started HRT long after menopause. Current clinical guidelines from the American College of Obstetricians and Gynecologists recommend starting HRT within 10 years of menopause onset and before age 60.
In November 2025, the FDA removed the “black box” warnings from HRT products after a comprehensive review of current scientific data indicating that HRT is not associated with an increased risk of cardiovascular disease, breast cancer or dementia.
“For many women, menopause symptoms can significantly affect their quality of life, yet questions about the cardiovascular safety of hormone therapy have remained,” said Stacey E. Rosen, M.D., FAHA, an expert in women’s heart health and past volunteer president of the American Heart Association (2025–2026). “This large, long-term study adds to growing evidence that today’s hormone therapy options may not increase the risk of heart disease, stroke or blood clots for healthy women who begin treatment around the time of menopause.”
“These findings can help women and their health care teams have more informed conversations about the benefits and risks of treatment based on their individual health needs.” Rosen, who was not involved in this study, is also executive director of the Katz Institute for Women’s Health and senior vice president of women’s health at Northwell Health in New York City.
The study to be presented at the American Heart Association’s Scientific Sessions evaluated data for more than 52,000 women ages 45 to 59 to assess whether the use of contemporary HRT is associated with an increased risk of atherosclerotic cardiovascular disease, venous thromboembolism (blood clots) or premature death (before age 80) in women who had not been previously diagnosed with cardiovascular disease.
After an average of 12 years of follow-up, the health outcomes were similar between the two groups of women, meaning the group that started taking HRT did not show an increase in cardiovascular events or early death compared with the group that was not taking HRT.
What are the study’s main findings?
- In the HRT group, 2,311 women (4.4%) had a heart attack, stroke or some type of related heart disease vs. 2,383 (4.6%) of the women in the no-HRT group.
- Death before age 80 occurred in 659 (1.3%) of the women taking HRT vs. 653 (1.2%) of the women not on any form of HRT.
- In both groups, 0.33% of women experienced a blood clot (174 women in the group taking HRT vs. 175 from the group that did not take HRT).
- The results were similar across all HRT formulations and administration routes (oral, patch or gel).
“Our results indicate that, for women in their mid-40s to late 50s with no history of heart disease or blood clots, the currently available hormone therapies prescribed to manage menopause symptoms do not appear to raise the risk of heart attack, stroke, clots or early death, even after long-term use,” Arbel said.
Study details, background and design:
- Using records from Clalit Health Services in Israel, researchers evaluated health data for 52,330 women ages 45 to 59 with no history of heart disease, blood clots or cancer.
- Half of the women had started HRT, primarily via oral and/or transdermal (patch) methods, while the other half had recently visited a gynecologist but did not begin HRT. The women in the second group did not take HRT throughout the study period.
- The researchers matched the women in both groups by age, BMI, cardiometabolic risk factors (blood pressure, cholesterol levels and whether they had been diagnosed with type 1 or type 2 diabetes), smoking status and socioeconomic status and compared their health data.
- Researchers evaluated the health records of both groups for up to 23 years, with an average follow-up period of 12 years, to compare the rate of cardiovascular disease, specifically heart attack, stroke and blood clots, as well as death from any cause before age 80.
The research has several limitations. It is an observational study, so it cannot prove a direct connection between HRT and heart health. The researchers also noted that there may be other differences between the women taking HRT and those not taking it that were not available or detailed in the health records, such as differences in exercise, diet, other health conditions and severity of menopause symptoms.
Additionally, the study grouped women by the first type of hormone therapy they used and did not account for any changes in HRT type or formulation throughout the follow-up period.
Key medical concepts
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Long-term study finds modern hormone replacement therapy not linked to heart disease risk (2026, November 2)
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