Short answer
For blood clots, the evidence points that way. A Danish nationwide study in The BMJ (September 2026) found oral estrogen linked to a 1.6 times higher rate of clots in veins, while patches and gels showed no increase. Absolute risks were small, the study was observational, and the right choice depends on your own health.
What the new study compared
Researchers used Denmark's national health registries to follow women aged 50 to 69 between 2003 and 2021. They identified 9,807 women who developed a clot in a vein (venous thromboembolism), 18,460 with an ischemic stroke and 11,974 with a heart attack, and matched each to women of the same birth year who did not.
Then they compared current hormone therapy use, by route and dose, with no current use. Women with a history of clots, cancer, liver disease or a known clotting disorder were not included.
Pill versus patch, in numbers
Oral estrogen, alone or with a progestin, was linked to higher rates of vein clots (hazard ratio 1.6), ischemic stroke (1.3) and heart attack (1.2). The highest risks came with oral estradiol above 1 mg a day used for more than five years, where stroke and heart attack rates were about 1.8 times higher.
Transdermal therapy, meaning patches and gels absorbed through the skin, was not linked to higher clot or stroke rates. One exception stood out: combined cyclic patches were linked to a higher heart attack rate (hazard ratio 2.1).
What it does and does not settle
This is an observational study, so it shows links, not proof that the route causes the difference. It also measured one outcome family: clots, strokes and heart attacks. It does not tell you which therapy best treats hot flashes, sleep or bone loss for you.
If you use hormone therapy or are considering it, the route is a reasonable question to raise with your clinician, along with your personal clot and heart risk. Do not stop or switch a prescription on your own. Educational content, not medical advice.
Related questions
I have had a blood clot before. Does this study apply to me?
No. Women with a past clot, cancer, liver disease or a known clotting disorder were excluded, so these numbers do not describe your risk. Your clinician needs to weigh your history directly.
Are vaginal estrogen creams part of this?
This study focused on oral and transdermal systemic therapy. Ask your clinician about low-dose vaginal products, which are a different category.
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Sources
Published 2026-10-03 · Last checked 2026-10-03
Educational content, not medical advice. Made for the United States.