Estrogen and Your Heart: What Every Woman Should Know

Estrogen plays a significant role in cardiovascular health—and more than 40 studies support its cardioprotective effects. Estrogen receptors are found throughout the blood vessels, including the coronary arteries, where estrogen helps promote vasodilation (better blood flow), reduce inflammation, and stabilize plaques that might otherwise rupture and trigger heart attacks. We’ve known since the Women’s Health Initiative (WHI) that heart disease risk increases in women around the time of menopause, and yet hormone therapy—especially oral estrogen, which can increase clotting factors due to first-pass liver metabolism—was unfairly blamed for that rise.

What’s often overlooked is that transdermal estrogen (patches, gels, sprays), which avoids the liver entirely, does not appear to increase clotting or platelet stickiness and may offer many of the benefits of estrogen with fewer cardiovascular risks. And here’s something else to consider: Heart disease is the leading cause of death in women, yet very few women who die of heart attacks were ever on HRT. That’s not evidence of harm—it may actually hint at missed opportunities for prevention. Many menopause advocates are calling for better research in this area, but until we get it, we have to make the best decisions we can with the evidence we have. That’s where I come in: I want every woman to feel well-informed, supported, and empowered to decide what’s right for her.

Estrogen’s Cardioprotective Role

More than 40 studies have shown that estrogen has a protective effect on the cardiovascular system. Why? Because blood vessels throughout the body—including your coronary arteries—have estrogen receptors. When estrogen is present, it promotes:

• Vasodilation (widening of blood vessels), improving blood flow

• Reduced inflammation, which helps prevent plaque rupture in arteries

• Healthier lipid profiles and more favorable endothelial function

Plaque rupture is what triggers many heart attacks. Without estrogen, these plaques are more prone to rupture. Estrogen helps keep things stable.

How a Heart Attack Happens

Inside your coronary arteries, cholesterol can build up over time, forming plaques. These can stay stable for years—but when a plaque ruptures, it exposes its contents to the bloodstream.

Your body sees this as an injury. Platelets (your blood’s clotting cells) rush to the site and start to clump together to form a clot. That clot can partially or completely block blood flow to the heart. If blood can’t reach a portion of the heart muscle, it causes damage—and that’s a heart attack.

Estrogen helps prevent these ruptures by reducing inflammation and keeping plaques more stable.

What We Learned from the WHI

The Women’s Health Initiative (WHI) raised concerns about hormone therapy and heart disease—but it’s important to understand the context. The women in that study were older (average age: 63) and many started oral estrogen years after menopause began. We now know that timing and route of estrogen matter.

Newer guidance from the North American Menopause Society (NAMS) supports that hormone therapy is generally safe when started within 10 years of menopause and before age 60—especially when using transdermal estrogen (patch, gel, or spray), which has fewer risks than oral forms.

Why I Only Prescribe Transdermal Estrogen

Transdermal estrogen bypasses the liver, avoiding what’s called “first-pass metabolism.” Oral estrogen is processed through the liver, which can increase clotting factors and platelet stickiness—raising cardiovascular risk, especially in older women.

Transdermal estrogen avoids this issue. That’s why I exclusively use transdermal forms in my clinic, especially for patients with cardiovascular risk factors.

Estrogen Loss at a Young Age = Higher Heart Risk

Women who go through early menopause—due to chemotherapy, ovary removal, or primary ovarian insufficiency—lose estrogen much earlier than average. This early loss removes the protective effect of estrogen on the blood vessels, increasing cardiovascular risk and even death from heart disease.

Younger women who stop menstruating due to stress, over-exercising, eating disorders, or hypothalamic dysfunction also face increased risk. These patients often have low estrogen and low FSH/LH levels—signals that the brain isn’t prompting the ovaries to produce hormones. Cortisol often rises, compounding inflammation and risk.

Should Estrogen Be Used for Heart Disease Prevention?

This is a nuanced conversation. The Cochrane Review on hormone therapy for primary prevention found that estrogen may reduce coronary events when started around menopause. However, hormone therapy is not officially recommended for heart disease prevention—especially in women already considered high risk.

That said, most of the studies that raised concerns about cardiovascular risk used oral estrogen. Transdermal estrogen doesn’t appear to increase platelet stickiness, and it’s reasonable to think that the risks may be lower—especially in healthy women. While we don’t have large-scale studies proving the safety of transdermal estrogen more than 10 years after menopause, we also don’t have strong evidence that it increases risk.

So for certain women over 60 or more than 10 years postmenopause—particularly those with persistent symptoms and no major cardiovascular disease—it may be reasonable to consider transdermal estrogen, after a thorough discussion of risks and benefits.

What I Encourage My Patients to Consider

If you're older than the typical age where we usually start HRT, here's what I want you to know: We don’t have conclusive proof of safety—or harm—when it comes to starting transdermal estrogen later in life. There are still a lot of unknowns. But many of my patients (and I myself) feel that the benefits of estrogen—especially for symptom relief, bone health, and overall wellness—may outweigh those unknowns.

Every woman has to decide for herself what she’s comfortable with. My job is to help you understand what we do know, acknowledge what we don’t, and guide you through the decision-making process with compassion and transparency.

I also want every one of my patients to be well-educated beyond the exam room. The more you know about menopause and hormone therapy, the better you can advocate for yourself—and the better I can support you with meaningful answers to your informed questions.

I truly love a well-educated patient.

A Tool I Frequently Use: The Coronary Artery Calcium Score

One of the ways I help assess cardiovascular risk in midlife is by ordering a coronary artery calcium (CAC) score. This is a quick, non-invasive CT scan that looks for plaque buildup in your coronary arteries. It's especially helpful for women who don't have obvious risk factors but want to get a clearer sense of their heart health before starting HRT.

A Bigger Picture to Consider

Heart disease is the leading cause of death in women. And yet, only a tiny percentage of women who die of heart attacks are on hormone therapy. Why? Because HRT has gotten an undeserved bad reputation—largely due to early interpretations of the WHI study—and as a result, far too many women have been denied access to it.

It’s hard to blame HRT for cardiovascular disease when so few women on HRT are dying from it. In fact, it raises an important question: Would heart disease rates in women decline if more had access to appropriate, individualized hormone therapy?

Many menopause experts and advocates are pushing for better data to answer that question. Unfortunately, there’s still not enough research being done in this area. So in the meantime, we make the best decisions we can with the information we have—rooted in evidence, logic, and your individual story.

If you're navigating these decisions, I’d love to help you sort through the information, weigh the risks and benefits, and come to a place of confidence and comfort. You're not alone—and you're not supposed to have all the answers.

Let’s talk about what’s best for you.