Yes, certain types of birth control can increase your risk of stroke. Combined hormonal contraceptives, the kind containing both estrogen and progestin, roughly double the risk of ischemic stroke compared to not using hormonal birth control. That sounds alarming, but the baseline risk for women of reproductive age is very low, so doubling a small number still leaves most users at low absolute risk. The details matter, though, because some methods, health conditions, and personal habits can push that risk much higher.
How Estrogen-Based Birth Control Affects Clotting
Stroke risk from birth control traces back to synthetic estrogen and its effects on the liver. When you take a combined oral contraceptive, the estrogen passes through your liver before reaching the rest of your body. The liver responds by ramping up production of several proteins involved in blood clotting, including factors II, VII, VIII, X, and fibrinogen. At the same time, levels of factor V, which helps regulate clotting, drop. The net result is blood that clots more easily than it should.
This prothrombotic shift is why estrogen-containing birth control is linked primarily to ischemic stroke, the type caused by a blood clot blocking an artery to the brain. There is also a smaller connection to hemorrhagic stroke (bleeding in the brain), specifically subarachnoid hemorrhage, where a meta-analysis of 15 studies found a 39% increased risk among oral contraceptive users. But the ischemic stroke link is stronger and more consistent across research.
Risk by Contraceptive Type
Not all birth control carries the same stroke risk. A large nationwide cohort study published in The BMJ compared contemporary methods head to head, and the differences are significant.
- Combined oral contraceptives (estrogen plus progestin pills): doubled the risk of ischemic stroke compared to non-use, with an adjusted rate ratio of 2.0.
- Vaginal ring (combined hormonal): rate ratio of 2.4 for ischemic stroke, higher than the pill.
- Contraceptive patch (combined hormonal): rate ratio of 3.4, the highest among all methods studied.
- Progestin-only pills (the minipill): a smaller but still elevated risk, with a rate ratio of 1.6.
- Hormonal IUD (progestin-only, intrauterine): no meaningful increase in ischemic stroke risk, with a rate ratio of 1.1.
The patch and ring delivering higher risk than the pill may seem counterintuitive since they bypass the liver’s “first pass” processing. But these methods maintain steadier, sometimes higher, hormone levels in the bloodstream, which appears to produce a greater clotting effect overall. Among estrogen-containing options, oral pills actually came in with the lowest stroke risk.
Who Faces the Highest Risk
For a healthy, nonsmoking woman under 35 with no other risk factors, the absolute risk of stroke on combined birth control remains quite small. Ischemic stroke incidence among women of reproductive age using hormonal contraception runs around 21 per 100,000 person-years. Most women will never have a problem. But certain factors multiply the risk dramatically.
Migraine With Aura
This is the single most important risk factor to know about. Women who experience migraine with aura (visual disturbances, numbness, or other sensory changes before a headache) and use combined hormonal contraceptives face a sixfold increased risk of ischemic stroke compared to women with neither risk factor. That’s not a small bump. It’s why the CDC’s Medical Eligibility Criteria classify combined hormonal contraceptives as generally unacceptable for women with migraine with aura. If you get migraines with visual symptoms, flashing lights, blind spots, or tingling before the headache hits, this applies to you.
Smoking, Especially After 35
Smoking and estrogen-based birth control are a dangerous combination, and the risk climbs steeply with age. Among oral contraceptive users who smoke, hemorrhagic stroke and heart attack account for 80% of cardiovascular deaths in women aged 20 to 24, rising to 97% in women aged 40 to 44. For women over 35, the absolute risk of arterial events increases sharply because cardiovascular disease becomes more common with age. Adding estrogen and cigarettes on top of that baseline creates a compounding effect.
High Blood Pressure
Hypertension is another condition that significantly increases stroke risk on its own. Combined with estrogen-based contraception, the risk compounds further. The meta-analysis on hemorrhagic stroke specifically found that current smoking, hypertension, and a history of migraine each independently amplified hemorrhagic stroke risk in contraceptive users. The CDC classifies combined hormonal methods as a category 3 or 4 (meaning “risks usually outweigh benefits” or “unacceptable health risk”) for women with uncontrolled or poorly controlled high blood pressure.
What Happens When You Stop
The elevated clotting risk from hormonal contraceptives is not permanent. It’s driven by the ongoing presence of synthetic estrogen in your system. Once you stop taking combined birth control, clotting factor levels return toward baseline. Research using previous hormonal contraceptive use as a reference group found that the stroke risk difference narrows: current users of combined contraceptives had a rate ratio of 1.6 compared to former users, suggesting that past use does not leave lasting cardiovascular risk.
Lower-Risk Alternatives
If you have risk factors for stroke, or simply want to minimize cardiovascular risk, several effective options exist. The hormonal IUD stands out because it releases progestin locally into the uterus with minimal systemic absorption, and studies show no meaningful increase in stroke risk. Progestin-only pills carry a smaller risk than combined methods, though the BMJ cohort study did find a modest elevation (rate ratio of 1.6 for ischemic stroke), so they’re not completely risk-free.
Nonhormonal methods carry no stroke risk at all. Copper IUDs, condoms, diaphragms, and fertility awareness methods keep hormones out of the equation entirely. For women with a personal history of stroke, blood clots, migraine with aura, or multiple cardiovascular risk factors, nonhormonal or progestin-only intrauterine options are what guidelines recommend.
Stroke Warning Signs to Recognize
Whether or not you use hormonal birth control, knowing stroke symptoms can save your life or prevent lasting damage. Strokes in younger women are rare but not unheard of, and they’re sometimes dismissed as anxiety or migraine. Watch for sudden numbness or weakness on one side of the body, difficulty speaking or understanding speech, sudden severe headache with no known cause, vision changes in one or both eyes, or sudden trouble walking or loss of coordination. These symptoms appearing together or individually warrant emergency medical attention, not a wait-and-see approach. The acronym FAST (face drooping, arm weakness, speech difficulty, time to call emergency services) remains a reliable quick check.