The best time to start hormone therapy might be sooner than you think
New research from CWRU suggests estrogen therapy started during perimenopause could improve symptom management with minimal negative health outcomes
Hot flashes and brain fog and lack of sleep—all these symptoms and more await women as they approach and go through menopause. For some, these symptoms can be debilitating and may even start as early as their 30s when entering perimenopause, the time leading up to menopause when the body starts producing less estrogen and progesterone.
While hormone therapy (HT) can help reduce symptoms, many women are hesitant to start it early—or at all—thanks to the 2002 Women’s Health Initiative (WHI) that tied HT to increased health risks. But research in the two decades since has challenged the WHI study, shifting the conversation not only around whether women should use HT, but when they should start it.
Preliminary research from Ify Chidi, a student in Case Western Reserve University School of Medicine’s Master of Public Health program, and her mentor Rachel Pope, MD, MPH, an associate professor at the school and obstetrician/gynecologist at University Hospitals, suggests that starting estrogen replacement therapy earlier may help manage unwanted symptoms without severe health risks.
Chidi first connected with Pope through her “Women’s Public Health” course last spring. For their final project, Pope asked students to use an electronic health record database to design and conduct original research. Chidi was inspired to investigate an interest Pope had shared throughout the class: studying the effects of early initiation of estrogen therapy during perimenopause based on the same outcomes examined in the 2002 WHI trial. The project ultimately evolved into collaborating on research that’s already made headlines.
Their study, which was presented at the Menopause Society’s 2025 Annual Meeting, analyzed the data of more than 60 million patient records to compare the impact of hormone therapy when started before menopause, after menopause, or not at all. It found that perimenopausal people who used hormone therapy in the 10 years before menopause were associated with a 64% lower incidence of breast cancer, and less than 10% higher incidence of heart attack and stroke, compared to menopausal women who never used hormone therapy. Menopausal women who started hormone therapy at the onset of menopause were associated with a 96% lower incidence of breast cancer, and less than 10% higher incidence of heart attack and stroke, compared to menopausal women who never used hormone therapy.
While the research is ongoing and results could be due in part to perimenopausal patients being younger, the study brings new knowledge to the half of the population who experience menopause and are weighing whether or not to use HT.
“While we can’t make definitive recommendations and conclusions of causality without further clinical and randomized control trials,” Chidi said, “we hope our findings will encourage more research and help patients feel empowered to have open, informed conversations about their options.”
The research couldn’t be timelier, with the Food and Drug Administration (FDA) announcing on Nov. 10 that it will remove the black box warning for hormone replacement therapy products for menopause. The FDA’s highest warning was added to these products shortly after the WHI study came out, significantly reducing the use of such medications. The new labels will display age-specific guidance that recommends starting it within 10 years of menopause onset.
Although more research is needed, the Case Western Reserve study marks a change in direction from the 2002 research that made people hesitant to consider hormone therapy in the first place. The evolving evidence may allow more women to feel confident partnering with their physicians to choose estrogen replacement as a way to improve their day-to-day in the face of life-altering menopause symptoms.
