New Study Suggests Hormone Therapy May Improve Certain Heart Health Markers in Menopausal Women
Korin Miller
May 20, 2025 (Prevention.com) – There has been a lot of chatter in and out of the scientific community about the use of hormone therapy for women in menopause. Preliminary results released in 2003 from the Women’s Health Initiative (WHI) clinical trial linked hormone therapy used to treat symptoms of menopause to a higher risk of developing serious health conditions, including heart disease and stroke. But research since then has found flaws in those findings.
Now, new research adds to the evidence challenging those initial findings on hormone therapy and heart health: It found that women in menopause who took oral hormone therapy showed improvements in certain biomarkers of cardiovascular health, including cholesterol.
Here’s what the research found, plus why hormone therapy may help heart health in menopause.
What did the study find?
The study, which was published in the journal Obstetrics & Gynecology, analyzed data from the WHI, which is a long-term national study focused on menopausal women. The researchers analyzed biomarkers linked with cardiovascular health in nearly 2,700 women over a six-year period.
The women were broken into two groups: Those who took estrogen and those who took a combination of estrogen and progesterone. The women were between the ages of 50 and 79. They provided blood samples at the start and various other times during the study.
The researchers discovered that hormone therapy had a positive impact on certain cardiovascular biomarkers in the group that took estrogen, as well as those who took estrogen and progesterone. Specifically, levels of LDL (“bad” cholesterol) dropped by about 11%, while total cholesterol and insulin resistance (when your body’s cells don’t respond as well to the hormone insulin) also dropped.
Levels of HDL (or “good” cholesterol) increased by 13% in the estrogen-only group and 7% in the estrogen-progesterone group.
Levels of a cholesterol molecule called lipoprotein(a) dropped by 15% and 20% in the estrogen-only and the estrogen-plus-progesterone groups. This finding surprised researchers because the molecule is believed to be mostly influenced by genetics.
There was one noteworthy unfavorable outcome: Triglycerides and coagulation factors, which are proteins in the blood that help form blood clots, increased, which is a potential downside of hormone therapy. For this reason, if you have a history of blood clots, it’s extra important to talk to your healthcare provider before taking hormone therapy.
Interestingly, the study found that, with the exception of triglycerides, hormone therapy had positive effects regardless of age, which contrasts to prior findings. “A lot of data suggests that the safest time to give hormone therapy is within 10 years of the menopause transition,” Dr. Streicher says. Still, the study concludes that the results may be used to counsel younger menopausal women with bothersome symptoms, likely because broader research shows that it’s safest to start hormone therapy closer to when menopause starts. (Note: hormone therapy isn’t FDA approved to treat the risk of coronary artery disease or stroke.)
Why is hormone therapy in menopause controversial?
It traces back to the early 2000s when those preliminary results were published from the WHI that linked hormone therapy to a higher risk of developing serious health conditions like heart disease and stroke. The study was actually stopped as a result and many women have avoided hormone therapy to treat symptoms of menopause since.
But the preliminary conclusions were later debunked. Other researchers analyzed the data and discovered that the original study looked at women who were 65 and up who already had a greater risk of heart attack, stroke, blood clots, and more—and that had skewed the data.
The preliminary findings also didn’t look at how old the women were when they started hormone therapy, which further muddled the results, explains Lauren Streicher, M.D., a clinical professor of obstetrics and gynecology at Northwestern University Feinberg School of Medicine.
In May 2024, a follow-up to the WHI study was released in JAMA with the conclusion that hormone therapy “is appropriate” for those with vasomotor symptoms (which could include hot flashes, for example) for interested women in early menopause without any contraindications.
Why might hormone therapy lower the risk of cardiovascular disease?
This isn’t the first study to suggest that hormone therapy may lower the risk of cardiovascular disease for women in menopause. Studies have shown that the age of initiation of therapy matters significantly, says Mary Jane Minkin, M.D., a clinical professor of obstetrics and gynecology and reproductive sciences at Yale School of Medicine and founder of Madame Ovary. “Women who initiate therapy within six years of menopause do benefit by significantly less thickening of the walls of their carotid arteries,” she says. “Animal studies in monkeys have shown this as well.” (Thickening of the carotid artery raises the risk of stroke.)
Estrogen levels “become nonexistent” when a woman enters menopause and that has a negative effect on the cardiovascular system, explains Sherry Ross, M.D., ob/gyn and women’s health expert at Providence Saint John’s Health Center in Santa Monica, CA. “Estrogen production helps maintain the elasticity in the blood vessels, reduces LDL or the ‘bad’ cholesterol, and promotes HDL or the ‘good’ cholesterol production,” she says. “Losing these heart health benefits increases the risk of heart disease in menopausal women.”
Taking estrogen replacement therapy can help by bringing back the benefits of elasticity in blood vessels, reducing LDL levels and promoting HDL levels, which support heart health, Dr. Ross says.
But it’s not entirely clear why this happens, says Dr. Streicher. She points out that there’s an association between women who have hot flashes and cardiovascular risks. But hormone therapy helps to tamp down on hot flashes.
“If you give women estrogen and these cardiovascular markers get better, is it because of the estrogen itself, the estrogen getting rid of the hot flashes, or both?” Dr. Streicher says. “We don’t know.”
What’s the best way to take care of your heart during menopause?
Taking hormone therapy is one option, but it’s a decision to make with your doctor, says Jennifer Wong, M.D., cardiologist and medical director of Non-Invasive Cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA.
“Regardless of whether one decides to start hormone therapy, women during menopause should eat a heart healthy diet, exercise, and try to obtain good quality sleep,” she says.
Dr. Ross specifically recommends taking these steps to protect your heart health in menopause:
- Eat a healthy colorful diet with whole grains and lean proteins
- Exercise for 150 minutes per week
- Try to maintain a healthy weight
- Aim for seven to eight hours of sleep a night
- Limit alcohol to no more than two to three drinks a week
- Try to stay on top of stress through relaxing activities like yoga, meditation, mindfulness, and psychotherapy
- Don’t smoke or vape
- Get regular health and heart screenings
“It is important to keep in mind that menopause is the next chapter of a woman’s life, not a phase that you go in and out of like puberty,” Dr. Ross says. “All of these symptoms can disrupt the quality of life, but they can be lessened or eliminated,” she says with lifestyle modifications, medications, and/or hormone replacement therapy. Talk to your doctor, or one certified through The Menopause Society for more personalized information.
Meet the experts: Mary Jane Minkin, M.D., a clinical professor of obstetrics and gynecology and reproductive sciences at Yale School of Medicine and founder of Madame Ovary; Sherry Ross, M.D., ob/gyn and women’s health expert at Providence Saint John’s Health Center in Santa Monica, CA; Jennifer Wong, M.D., cardiologist and medical director of Non-Invasive Cardiology at MemorialCare Heart and Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA; Lauren Streicher, M.D., a clinical professor of obstetrics and gynecology at Northwestern University Feinberg School of Medicine