RICHMOND, Va. (Sept. 8, 2026) — A study led by Virginia Commonwealth University and the University of Pittsburgh provides pivotal insights into one of the most debated questions in women’s health: how does hormone therapy for menopause symptoms affect cardiovascular disease risk when used in peri- or early postmenopause?
By analyzing 20 years of health data from women with vasomotor symptoms participating in the Study of Women’s Health Across the Nation (SWAN), the researchers found hormone therapy initiated during peri- or early postmenopause was linked to a reduced risk of cardiovascular disease events by 22% compared to those who did not use hormone therapy. The protective effect of hormone therapy was strongest among Black women and women who initiated therapy within 10 years of menopause onset.
The study is the first of its kind in the United States to assess risk of future cardiovascular events among women with vasomotor symptoms who use therapy during peri- and early postmenopause stages. The findings, published today in the JAMA Internal Medicine, help address an important gap in understanding how the timing of hormone therapy influences the likelihood of cardiovascular disease events like stroke or heart failure, among others.
“The menopause transition represents a critical window for understanding how hormone therapy may relate to cardiovascular disease risk,” said Samar R. El Khoudary , Ph.D., M.P.H., professor and chair of the Department of Epidemiology at the VCU School of Public Health, a SWAN investigator and scientific leader and one of the senior researchers who led the study. “Our findings suggest that timing of initiation may influence cardiovascular outcomes.”
The researchers note that these findings do not support using hormone therapy for cardiovascular disease prevention. As with any treatment, potential benefits must be weighed against risks, including the increased breast cancer risk observed with a longer duration of use. Further, this study was not a randomized controlled trial, the gold standard method to test biomedical treatments.
“These findings point to women with vasomotor symptoms as those who may show cardiovascular benefit from hormone therapy initiated during the perimenopause and postmenopausal years,” said Rebecca C. Thurston , Ph.D., associate dean for Women’s Health Research at the University of Pittsburgh School of Medicine , a SWAN principal investigator and one of the senior researchers who led the study. “However, conclusions should be tempered by the observational nature of the study, and findings should not guide clinical practice.”
Clearing confusion on menopause hormone therapy and cardiovascular disease
Vasomotor symptoms, also known as hot flashes and night sweats, affect up to 80% of women during their menopause transition . These symptoms last an average of seven to ten years , with their frequency and severity building up through perimenopause and typically peaking in early postmenopause.
Hormone therapy, which replaces estrogen and progesterone that women’s bodies stop producing after menopause, is currently the most effective treatment for mitigating these sensations of intense heat. However, clinical trials led by the Women’s Health Initiative in the early 2000s raised initial alarm over this therapy’s impact on heart diseases, stroke, breast cancer and other risks. This led to years of reluctance from both patients and providers in using this therapy.
“Hot flashes and night sweats have a significant impact on a woman’s quality of life and ability to work productively,” El Khoudary said. “While hormone therapy is an effective treatment for these symptoms, questions have remained about its cardiovascular effects, particularly the importance of when treatment is initiated during the menopause transition.”
More recent research suggests that the effect hormone therapy has on women's hearts and vascular systems may vary depending on age and timing of treatment, with women younger than 60 who begin treatment closer to menopause onset having different levels of risk.
In 2026, the U.S. Food and Drug Administration removed “black box” warnings from hormone therapy products, reflecting evolving evidence on the benefits and risks of treatment.
How early intervention with menopause hormone therapy affects women’s risk for cardiovascular disease events
There has been a growing number of studies over the past 20 years focusing on hormone therapy and cardiovascular risk. However, no clinical trials have specifically evaluated the risk of cardiovascular events from taking hormone therapy for vasomotor symptoms during the menopause transition.
To fill this knowledge gap, researchers from VCU and the University of Pittsburgh analyzed long-term data from the SWAN project, which is the largest and longest observational study of its kind in the United States to better understand the health impacts of the menopause transition in women.
The team used clinical data collected between 1997 and 2017 from more than 2,700 women who reported vasomotor symptoms and who had not previously experienced any cardiovascular events. Based on self-reported patient data, researchers then examined whether women who started hormone therapy for vasomotor symptoms were more or less likely to experience cardiovascular events, such as stroke, congestive heart failure, heart attack and revascularization procedures, than women who did not begin treatment.
“By using data from the SWAN study, we essentially were able to emulate a series of hypothetical clinical trials to gain a deeper understanding into how hormone therapy taken to mitigate vasomotor symptoms during peri- and early postmenopause influences cardiovascular risk over time,” El Khoudary said. “It allowed us to examine clinically meaningful cardiovascular disease events over long-term follow-up in a population and treatment window that has been challenging to study prospectively.”
The analysis suggested that initiating hormone therapy in peri- or early postmenopause among women with vasomotor symptoms reduced the risk of cardiovascular disease events by 22% compared with not starting therapy.
The cardiovascular effect of hormone therapy initiation also varied by timing, race and ethnicity, such as:
“The differences in cardiovascular outcomes by race and ethnicity are notable, particularly because Black women are more likely to experience severe vasomotor symptoms,” El Khoudary said. “These findings highlight the need to better understand how hormone therapy timing may influence cardiovascular outcomes across diverse populations.”
It’s unclear why cardiovascular disease risk differs based on the timing of hormone therapy use, but the team believes it may be linked to differences in blood vessel health as we age.
“We hope these findings help inform conversations between women and their healthcare providers about the potential benefits and risks of hormone therapy for vasomotor symptoms,” El Khoudary said. “Studies like this can provide useful information, but the results should be interpreted carefully because other factors that were not measured may have influenced the findings. The findings also highlight the need for future clinical trials focused specifically on women during the menopause transition.”
“Our findings are thought provoking. However, caution should be exercised in their interpretation,” Thurston said. “Women who elect to use hormone therapy differ from women who do not on multiple characteristics, such as race, ethnicity, socioeconomic position, and access to healthcare that this study cannot fully address. These data point to the need for a clinical trial specifically designed among midlife women with vasomotor symptoms.”
The SWAN study is supported by grants from the Department of Health and Human Services and National Institutes of Health, including the National Institute of Aging, the National Institute of Nursing Research, and the NIH Office of Research on Women’s Health.
JAMA Internal Medicine
10.1001/jamainternmed.2026.2922
Menopausal Hormone Therapy and Cardiovascular Risk in Midlife Women With Vasomotor Symptoms
8-Sep-2026