Oral Estradiol: A look at the benefits and risk

When women ask about hormone options in menopause, they’re often told not to take oral estradiol. I feel that blanket statement is unfair, because it leads women to believe it isn’t an option when the discussion is much more nuanced. If you’ve been told that estrogen pills cause blood clots, heart attacks, strokes, breast cancer, and dementia, you’re not alone. Most of us, patients and clinicians alike, learned about hormone therapy through the headlines of the 2002 WHI study. This month we’re focusing on oral estradiol: what the research actually shows, and why it’s harder to interpret than the headlines suggest. 

Why the numbers are so confusing 

Most of the famous studies didn’t test the kind of estrogen we use today. The Women’s Health Initiative (WHI) used conjugated equine estrogen (CEE), a mix of estrogens made from pregnant mares’ urine, often paired with medroxyprogesterone acetate, a synthetic progestin we should not be prescribing now (but that’s a post for another day). Oral estradiol is made from plants, not synthetically. It’s bio-identical to human estrogen and behaves differently from CEE in the body. 

Who was studied matters too. WHI enrolled women ages 50 to 79, averaging 63, and many were more than 10 years past menopause. Two-thirds were overweight or obese. Many large studies also don’t know how many years past menopause women were when they started, or whether they had other risk factors like smoking, a sedentary lifestyle, or risk-enhancing medications. When a study can’t account for those things, its result is an average across very different women, and it’s hard to know where you fall. 

No wonder we’re confused! Most practitioners don’t break down the studies and just report what they’re told. Let’s go further! 

How your body handles an estradiol pill 

When you swallow estradiol, it goes to your liver first. Your liver gets a concentrated dose, much higher than what shows up in a blood test, and responds by making more of the proteins that help blood clot and fewer of the ones that keep clotting in check. That same first pass is also why oral estradiol lowers LDL cholesterol and lipoprotein(a) more than a patch or gel does, and why it helps your liver manage blood sugar. The benefits and the risk come as a package. Patches, gels, and sprays skip the first pass, so they don’t carry the same clot risk, and they don’t have the same cholesterol and blood sugar effects.

Blood clots

“Clot risk” often lumps together three different things: clots in the veins (legs or lungs), strokes, and heart attacks. Strokes and heart attacks happen in the arteries and are driven mostly by plaque, blood pressure, and the health of your blood vessels. Clots in the veins come from changes in your blood’s clotting proteins, and that’s where oral estrogen has its most consistent effect. 

Two things shape that risk over time. The first is age. Vein clot risk rises steadily as we get older, with or without hormones, so the same percentage increase from estrogen produces more extra clots in a 68-year-old than in a 52-year-old. That’s one reason we prefer to start hormone therapy close to menopause. The second is time on therapy. Clot risk is highest in the first year, partly because women with an unrecognized tendency to clot tend to have their clot early. After that the risk comes down, but it stays slightly elevated for as long as you take oral estrogen. 

What the newest study shows. A large Danish study published this month (2026) looked at women aged 50 to 69 taking oral estradiol, excluding women who’d already had a clot or had a known clotting disorder. Among women not on hormones, about 16 out of every 10,000 had a clot each year. Oral estradiol raised that risk by about 60%, which sounds alarming until you see the actual numbers: about 9 extra clots per 10,000 women per year, or one extra clot for every 1,055 women taking it for a year. The increase showed up at every dose and every length of use. Women using patches, gels, or sprays had no increase at all. 

The older estrogen used in WHI carried more risk. In a large UK study comparing the two directly, oral estradiol had about 15 to 17% lower clot risk than CEE. 

Hard to conceptualize? Let’s put it in perspective with clot risks most of us have already accepted: 

Situation Clots per 10,000 women per ye

The extra risk from oral estradiol in midlife is in the same range as the extra risk from the pill in your 20s and 30s, which many of us took for years without a second thought. In a US study of women aged 50 to 64, birth control pills carried more than three times the clot risk of oral

Why your own health matters so much. That 9 per 10,000 is an average, and clot risks multiply rather than add. In WHI, compared with normal-weight women on placebo, overweight women on hormones had nearly 4 times the clot risk, obese women more than 5 times, and women carrying factor V Leiden (a common inherited clotting mutation) nearly 7 times. The Danish study didn’t have information on weight, smoking, or time since menopause, and it blends women in their early 50s with women in their late 60s. For a lean, healthy woman in her early 50s, our rough estimate is closer to 5 or 6 extra clots per 10,000 women per year. That’s an illustration, not a figure from the study, but it shows how much your own health shapes your risk. 

Age matters in a specific way too. In WHI, women who started hormones in their 70s had more than 7 times the clot risk of women in their 50s on placebo. That’s very different from a woman who started near menopause and has been on estradiol for years, since she’s long past the higher-risk first year. Her baseline risk still rises with age, which is why we reassess as you get older, and many women switch to a patch or gel in their 60s to keep the benefits while taking clot risk off the table. 

Clot risk also isn’t the whole picture. Estrogen protects bone, lowers LDL and Lp(a), and is linked to less type 2 diabetes. For women who start near menopause, the research points to fewer deaths and less heart disease overall. For a healthy woman, those benefits can outweigh a small increase in clot risk, and that’s the balance we look at together. 

Is oral estradiol right for you? 

This is a conversation to have with your provider, because your health history shapes your risk far more than any headline number. There’s no single blood test for clot risk, so most of what we need comes from your history. That’s why we ask so many questions at your first visit. Here’s what we look for: 

• A past blood clot in your legs or lungs, especially during pregnancy, after having a baby, or while on birth control pills 

• A parent, sibling, or child who had a clot, especially before age 50 or without an obvious cause • A known clotting disorder, such as factor V Leiden 

• A higher BMI 

• Smoking 

• Starting hormones more than 10 years after your last period, or after age 60 • Migraine with aura, high triglycerides, or liver or gallbladder disease 

• Active cancer, lupus, or inflammatory bowel disease

• Upcoming surgery or long periods of sitting or immobility 

If your family history raises a flag, we may check for inherited clotting disorders before choosing your route. If any of these apply to you, it doesn’t mean you can’t take estrogen. It usually means a patch, gel, or spray is the better fit. On the other hand, oral estradiol can be especially appealing if your LDL or Lp(a) is high, or if you’re insulin resistant, as long as your clot risk is low and your triglycerides are normal. 

Heart attacks, strokes, and the timing hypothesis 

The WHI finding that frightened everyone was a jump in heart attacks in the first year. That jump was concentrated in women who started hormones many years after menopause, when plaque had already built up in their arteries, and it faded over the following years. This is the timing hypothesis: estrogen started within 10 years of menopause, while arteries are still healthy, seems to slow plaque buildup, while estrogen started in arteries that already have plaque can tip the balance the other way. 

I recently had the privilege of hearing Dr. Hodis speak at a Worldlink Medical conference. His ELITE trial at USC looked at oral estradiol in early versus late starters. Women within 6 years of menopause who took oral estradiol had slower thickening of their artery walls than women on placebo, while women 10 or more years out got no benefit. In a Danish trial (DOPS), women started on oral estradiol shortly after menopause had fewer deaths, heart attacks, and heart failure hospitalizations over the following decade. And a Cochrane review of oral hormone trials estimated that for every 1,000 women under 60 who started hormones, there would be about 6 fewer deaths and 8 fewer cases of heart disease over roughly 7 years. 

The new Danish study adds a dose picture. Across all women on oral estradiol, the extra risk was about one stroke per 1,642 women per year and one heart attack per 3,846, concentrated in women taking more than 1 mg a day long term. Transdermal estradiol didn’t raise stroke or heart attack risk overall. Hormone therapy still isn’t FDA approved to prevent heart disease, but starting near menopause at a moderate dose looks heart-friendly. 

Dementia and brain health 

This is one of the most common reasons women ask about estrogen, so it’s worth being precise. The WHI memory study found more dementia in women who started hormones at 65 or older, on CEE. When researchers tested oral estradiol directly in the ELITE trial, memory and thinking scores didn’t differ from placebo after about 5 years, whether women started early or late. So oral estradiol started near menopause doesn’t appear to harm the brain. 

What about protection? Some large observational studies have found lower rates of Alzheimer’s in women who used hormones around menopause, while others haven’t, and no clinical trial has shown that estrogen prevents dementia. So we don’t prescribe it for that purpose. 

Where estrogen clearly helps is with the symptoms that make midlife brains feel foggy. Hot flashes and night sweats disrupt sleep, and frequent hot flashes have been linked with poorer memory performance. Treating them often means better sleep, better focus, and feeling more like yourself. In the KEEPS trial, women on oral estrogen also had lower anxiety and depression scores. For many women, that’s the brain benefit they notice most, even if it doesn’t show up on a dementia test. 

There’s a metabolic side too. Type 2 diabetes and insulin resistance are linked to higher dementia risk, and some researchers call Alzheimer’s “type 3 diabetes” because brain health seems so closely tied to blood sugar regulation. That idea is still being studied. But since oral estradiol improves insulin sensitivity and lowers the risk of type 2 diabetes, it may support brain health indirectly. We can’t say yet that it lowers dementia risk this way. What we can say is that protecting your metabolic health is one of the best things you can do for your brain, and hormone therapy can be part of that, alongside strength training, nutrition, and sleep. 

Breast cancer 

We’ll cover this in more depth soon, but the WHI showed that women without a uterus who took CEE alone had fewer breast cancers and fewer breast cancer deaths than women on placebo, even 20 years later. The bigger factor is which progestogen is added for women who still have a uterus. In WHI, adding the synthetic progestin MPA raised breast cancer incidence. We’ll cover the WHI, breast cancer, and progestogens in their own newsletter. 

Blood sugar and insulin 

This is one place where the pill has a real edge. Estrogen helps your body respond to insulin, and in two large randomized trials, women taking hormones developed type 2 diabetes less often, about 20% less in WHI. In a French study of more than 63,000 women, the protective effect was stronger with oral estrogen than with patches or gels, even after accounting for weight. The reason is that same first pass through the liver: oral estrogen helps the liver hold back from releasing extra sugar into the bloodstream. 

If you’re insulin resistant, have prediabetes, or have a strong family history of diabetes, oral estradiol may be worth a closer look, as long as your clot risk is low and your triglycerides are in a good range. For women who already have diabetes and low cardiovascular risk, oral estradiol is often the preferred choice. It isn’t approved as a diabetes treatment, but for the right woman it can be one more piece of her metabolic health plan.

Gallbladder 

Because oral estrogen passes through the liver, it raises the risk of gallstones. In the UK Million Women Study, about 2 in 100 women on oral hormones had their gallbladder removed over five years, compared with 1.3 on patches or gels and 1.1 in women who never took hormones. The risk was lower with estradiol than with CEE, and lower at 1 mg or less. If you’ve had gallbladder trouble, transdermal is usually the better choice. 

Other benefits 

Oral estradiol works just as well as patches, gels, and sprays for the many many associated symptoms of hormone deficiency such as hot flashes, night sweats, joint pain, mood, and sleep. Estrogen in any form is FDA approved to prevent osteoporosis, and it works best in the years around menopause, when bone loss is fastest. In WHI, women on hormones had fewer fractures, including hip fractures. The protection lasts only as long as you take it, so if you stop, bone loss picks back up. That’s worth planning around with your provider. 

What about dose? 

In the Danish study, clot risk was slightly higher at every oral dose, while stroke and heart attack increases were concentrated above 1 mg a day. But the milligrams on the bottle don’t tell you how much estrogen your body absorbs. Absorption varies a lot, so some women on 2 mg run lower blood levels than others on 1 mg, and none of these studies measured blood levels. A blood test also can’t show the concentrated dose your liver saw on the first pass, and much of oral estradiol is converted to estrone, which a standard estradiol test doesn’t pick up. So we look at your symptoms, labs, and risk profile together to decide on dosing. 

The bottom line 

Oral estradiol isn’t the dangerous pill the old headlines made it out to be, and it isn’t right for everyone. For a healthy woman near menopause, its absolute risks are small, and its benefits for symptoms, bone, cholesterol, and blood sugar are real. For a woman with clot risk factors, a patch, gel, or spray offers most of the same benefits without the liver effect. Where you land depends on your history, your labs, and how you live, and that’s the conversation we’re here to have with you. 

Your Menopause Concierge 

Lisa Arshawsky, MSN, WHNP-BC, CNM 

Sources 

1. Berggreen J, et al. Contemporary menopausal hormone therapy and thrombotic disease: nationwide nested case-control study. BMJ. 2026;394:e100688.

2. Vinogradova Y, Coupland C, Hippisley-Cox J. Use of hormone replacement therapy and risk of venous thromboembolism. BMJ. 2019;364:k4810. 

3. Cushman M, et al. Estrogen plus progestin and risk of venous thrombosis. JAMA. 2004;292(13):1573-1580. 4. Weller SC, et al. Hormone exposure and venous thromboembolism in commercially insured women aged 50 to 64 years. Res Pract Thromb Haemost. 2023. 

5. ASRM Practice Committee. Combined hormonal contraception and the risk of venous thromboembolism: a guideline. Fertil Steril. 2017;107(1):43-51. 

6. Boardman HMP, et al. Hormone therapy for preventing cardiovascular disease in post-menopausal women. Cochrane Database Syst Rev. 2015;(3):CD002229. 

7. Manson JE, et al. Estrogen plus progestin and the risk of coronary heart disease. N Engl J Med. 2003;349(6):523-534. 8. Hodis HN, et al. Vascular effects of early versus late postmenopausal treatment with estradiol (ELITE). N Engl J Med. 2016;374(13):1221-1231. 

9. Schierbeck LL, et al. Effect of hormone replacement therapy on cardiovascular events in recently postmenopausal women (DOPS). BMJ. 2012;345:e6409. 

10. Henderson VW, et al. Cognitive effects of estradiol after menopause: a randomized trial of the timing hypothesis (ELITE-Cog). Neurology. 2016;87(7):699-708. 

11. Shumaker SA, et al. Estrogen plus progestin and the incidence of dementia and mild cognitive impairment in postmenopausal women (WHIMS). JAMA. 2003;289(20):2651-2662. 

12. Gleason CE, et al. Effects of hormone therapy on cognition and mood in recently postmenopausal women (KEEPS-Cog). PLoS Med. 2015;12(6):e1001833. 

13. Chlebowski RT, et al. Association of menopausal hormone therapy with breast cancer incidence and mortality during long-term follow-up of the Women’s Health Initiative randomized clinical trials. JAMA. 2020;324(4):369-380. 14. Margolis KL, et al. Effect of oestrogen plus progestin on the incidence of diabetes in postmenopausal women: results from the Women’s Health Initiative Hormone Trial. Diabetologia. 2004;47(7):1175-1187. 

15. de Lauzon-Guillain B, et al. Menopausal hormone therapy and new-onset diabetes in the French E3N cohort. Diabetologia. 2009;52(10):2092-2100. 

16. Mauvais-Jarvis F, et al. Menopausal hormone therapy and type 2 diabetes prevention: evidence, mechanisms, and clinical implications. Endocr Rev. 2017;38(3):173-188. 

17. Liu B, et al. Gallbladder disease and use of transdermal versus oral hormone replacement therapy in postmenopausal women: prospective cohort study. BMJ. 2008;337:a386. 

18. Cauley JA, et al. Effects of estrogen plus progestin on risk of fracture and bone mineral density: the Women’s Health Initiative randomized trial. JAMA. 2003;290(13):1729-1738. 

19. Anagnostis P, et al. The effect of hormone replacement therapy and tibolone on lipoprotein(a) concentrations in postmenopausal women: a systematic review and meta-analysis. Maturitas. 2017;99:27-36.