If you’ve ever read the tiny, terrifying print inside a birth control package, you’ve probably seen the words “blood clot” and felt your stomach drop. You just wanted reliable contraception, not a crash course in hematology.
The good news: for most healthy people, the risk of blood clots from birth control is still low. The not-so-fun news: some forms of hormonal birth control really do increase your risk, especially if you already have other risk factors.
This article breaks down what the science actually says about birth control and blood clots, which methods carry more risk, who needs to be extra careful, and what warning signs you should never ignore. Think of it as a friendly explainer from that one friend who reads clinical guidelines for funjust remember it’s not a substitute for medical advice. Always talk with your own clinician about your specific situation.
How Birth Control and Blood Clots Are Connected
When people talk about “blood clots” and birth control, they’re usually referring to venous thromboembolism (VTE)a blood clot that forms in a vein. This includes:
- Deep vein thrombosis (DVT): a clot in a deep vein, usually in the leg.
- Pulmonary embolism (PE): a clot that travels to the lungs, which can be life-threatening.
Hormonal birth control, especially methods that contain estrogen, can shift the body’s clotting balance. Estrogen affects several clotting factors in the blood, nudging the system a little closer to “clot” and a little farther from “dissolve.” Studies of combined hormonal contraceptives (CHCs)like the pill, patch, and ringconsistently show a higher risk of VTE compared with not using hormonal birth control.
The exact risk depends on:
- Estrogen dose (higher doses generally mean higher clot risk).
- Type of progestin (some newer progestins, like drospirenone, appear to carry slightly higher risk than older ones such as levonorgestrel).
- Your own health and family historythings like smoking, obesity, prior clots, or inherited clotting conditions can stack the deck.
Relative risk vs. absolute risk (a quick reality check)
Here’s where the numbers help calm the anxiety a bit. In people of reproductive age not using hormonal birth control, the risk of VTE is roughly 1–5 cases per 10,000 women per year. With combined hormonal birth control, that rises to around 3–15 cases per 10,000 women per year, depending on the formulation.
WebMD estimates that the chance of a clot over 10 years on the pill is about 0.3%–1%, which is small but real. For comparison, the risk of blood clots is substantially higher during pregnancy and the postpartum period than on most modern combined birth control methods.
So yes, estrogen-containing birth control increases your clot risk, but we’re going from “very rare” to “still rare, but more likely than before.” That’s why guidelines focus so much on individual risk factors: for some people, the increased risk is acceptable; for others, it’s a hard no.
Which Birth Control Methods Carry the Highest Clot Risk?
Not all birth control is created equal when it comes to blood clots. Here’s the general risk ladder, from higher to lower clot risk, based on current research.
1. Combined hormonal pills (estrogen + progestin)
Combined oral contraceptives (COCs) are the classic pill: they contain an estrogen (usually ethinyl estradiol) plus a progestin. Large reviews and guidelines agree that COCs increase VTE risk by about 3–4 times compared with non-use, though the absolute risk remains low in healthy young people.
Within this group, risk can vary with:
- Estrogen dose: Pills with 50 micrograms of ethinyl estradiol carry more risk than those with lower doses. High-dose formulations (>50 mcg) are no longer commonly used in the U.S. for this reason.
- Progestin type: Some data suggest that pills with newer progestins like drospirenone may have a higher clot risk than those with older progestins like levonorgestrel, though findings aren’t perfectly consistent.
For most healthy users without additional risk factors, many experts consider low-dose combined pills an acceptable optionbut the trade-offs should be discussed clearly with a clinician.
2. The patch and the vaginal ring
The transdermal patch and vaginal ring are also combined hormonal methods. Some studies suggest that these may have similar or even slightly higher VTE risk compared with combined pills, possibly because of continuous estrogen exposure.
More recent research has also linked these methods to small but measurable increases in stroke and heart attack risk compared with non-users, especially in older users or those with other cardiovascular risk factors. Again, these events remain rare in absolute terms, but they’re part of the risk conversation.
3. Progestin-only methods
Progestin-only birth control includes:
- Progestin-only pill (“mini-pill”)
- Hormonal IUDs (levonorgestrel-releasing IUDs)
- Implant (like etonogestrel implants)
- Injectable depot medroxyprogesterone acetate (DMPA)
Overall, research suggests that most progestin-only methods do not appear to meaningfully increase VTE risk compared with no hormonal contraceptionespecially progestin-only pills, implants, and hormonal IUDs. Some newer data highlight a possible increased risk with the DMPA injection, particularly in people who already have clotting risk factors, but evidence is still evolving.
Because they lack estrogen, progestin-only methods are often preferred for people with a history of clots or very high clot risk, though decisions are made case by case.
4. Non-hormonal methods
Non-hormonal birth control methodslike the copper IUD, condoms, diaphragms, and fertility awareness methodsdo not increase blood clot risk. For people with strong contraindications to estrogen and concern even about progestin-only methods, these can be excellent options.
Other Factors That Change Your Blood Clot Risk
Here’s the key point: birth control is one piece of the puzzle, not the whole picture. The Centers for Disease Control and Prevention (CDC) lists several major risk factors for blood clots:
- Older age (risk rises after about 40)
- Overweight or obesity
- Smoking, especially age 35 and above
- Recent surgery, injury, or hospitalization
- Prolonged immobility (long flights, bed rest, cast on a leg)
- Pregnancy and the postpartum period (up to 3 months after birth)
- History of blood clots or inherited clotting disorders (such as Factor V Leiden)
- Certain chronic conditions (cancer, autoimmune disease, heart failure, and more)
If you stack several of these risk factors on top of an estrogen-containing birth control method, the overall risk can increase significantly. That’s why guidelines often recommend avoiding combined hormonal methods in people who smoke and are over 35, have a strong personal or family history of clots, or have certain cardiovascular or clotting conditions.
Signs and Symptoms You Should Never Ignore
Regardless of what method you use, it’s crucial to know the “red flag” symptoms of blood clots. If you’re on hormonal birth control and notice any of the following, seek emergency care immediatelydo not wait it out.
Possible symptoms of DVT (leg clot)
- New swelling in one leg (especially calf or thigh)
- Leg pain or tenderness that doesn’t match your usual muscle soreness
- Warmth, redness, or discoloration of the leg
Possible symptoms of pulmonary embolism (clot in the lung)
- Sudden shortness of breath
- Sharp chest pain that may get worse when you breathe in
- Rapid heartbeat
- Coughing up blood
- Feeling lightheaded or faint
Other emergency red flags
- Sudden severe headache, difficulty speaking, weakness on one side (possible stroke)
- Crushing chest pain, sweating, nausea (possible heart attack)
These symptoms can have many causes, but they’re always an emergency. If something feels “seriously not right,” trust that feeling and get help.
Who Should Be Extra Cautious With Estrogen-Containing Birth Control?
Guidelines from professional organizations say that combined hormonal methods are usually not recommended for people with certain conditions because of higher clot and cardiovascular risk. These commonly include:
- Current or past deep vein thrombosis or pulmonary embolism
- Known inherited thrombophilia (like Factor V Leiden or prothrombin gene mutation) with significant risk
- Major surgery with prolonged immobilization
- Certain types of migraine with aura
- Uncontrolled high blood pressure, some heart diseases, or history of stroke or heart attack
- Smokers over age 35
- Some people with very high BMI or multiple cardiovascular risk factors
If any of these apply to youor if you have a strong family history of early blood clotsyour clinician may steer you toward progestin-only or non-hormonal options instead.
One important nuance: having a relative who had a clot doesn’t automatically mean you can’t use estrogen-containing birth control, but it’s a big reason to have a detailed risk conversation and possibly consider testing for clotting disorders in some situations.
Talking With Your Clinician: Questions to Ask
Picking birth control shouldn’t feel like spinning a roulette wheel with your circulatory system. A good visit with your clinician will walk through your priorities and your risk profile.
Helpful questions to bring to the appointment include:
- “Given my health history, how high is my personal risk of blood clots if I use an estrogen-containing method?”
- “Would a progestin-only or non-hormonal option be safer for me?”
- “What are the absolute numbershow many people like me actually get blood clots on this method?”
- “How does this risk compare to pregnancy or not using contraception at all?”
- “What symptoms should make me stop the method and seek care immediately?”
- “Can we review all of my other risk factorssmoking, BMI, family history, recent surgery, and so on?”
It’s completely reasonable to say, “I’m worried about blood clots, but I also care a lot about acne control/period pain/heavy bleeding. What are my options?” Birth control decisions are rarely just about pregnancy prevention; they’re about the whole person.
Myth-Busting: Common Questions About Birth Control and Clots
“If I take the pill, I’m guaranteed to get a clot.”
Nope. Even with combined hormonal methods, clots remain uncommon in otherwise healthy people. The risk goes up, but for most users it’s still low in absolute terms.
“Natural or ‘bio-identical’ hormones are always safe.”
Not necessarily. Some “natural estrogen” formulations still affect clotting factors. Risk depends on dose, route, and the overall hormone mix, not just whether a label says “natural.”
“Progestin-only birth control can’t cause clots at all.”
So far, most evidence suggests that progestin-only methods (especially pills, implants, and hormonal IUDs) have little to no added VTE risk in the general population, but research continuesparticularly for DMPA injections and high-risk groups. “Very low risk” is not the same as “zero risk.”
“If I’ve been on the pill for years without issues, I’m in the clear.”
Having used a method without problems is reassuring, but risk isn’t fixed. As you age, gain or lose weight, start smoking, stop smoking, or develop new medical conditions, your risk profile may change. It’s a good idea to revisit your birth control choice periodically with your clinician.
Real-Life Experiences: What Living With This Risk Actually Feels Like
Statistics are helpful, but real life doesn’t feel like a graphit feels like lying awake at night wondering, “Is my leg supposed to hurt like that?” While everyone’s story is unique, here are a few common patterns people describe when navigating birth control and blood clot risk.
1. The “I read the insert and panicked” phase
For many people, the journey starts with the mini-booklet folded into the pill pack. You open it, expecting a few basic bullet points, and instead find an encyclopedia of terrifying worst-case scenarios. It’s normal to feel anxious after reading phrases like “life-threatening clot” or “increased risk of stroke.”
What helps in this stage is context. Talking to a clinician who can translate “3–15 per 10,000” into something understandable (“We’re talking about a small risk, but we still take it seriously”) often makes a big difference emotionally. Some people decide, “Okay, the benefits of this pill are worth it for me.” Others say, “I’d rather not worry about this at allwhat else can I use?” Both responses are valid.
2. The “family history plot twist” moment
Another common experience: someone starts or continues a combined method, then later learns a relative had a serious blood clot in their 30s or 40s. Suddenly, what felt like a routine choice becomes a bigger question.
In many of these cases, people describe feeling caught between fear and frustration. They may be happy with how the pill controls their periods or acne, but now they’re worried they’ve been “playing with fire.” A good clinician will usually:
- Review the family history in detail (age at clot, location, any known inherited disorders).
- Consider whether thrombophilia testing is appropriate.
- Walk through alternative birth control options with lower or no clot risk.
Even when no inherited clotting condition is found, some people feel more at peace switching to a progestin-only pill, hormonal IUD, or copper IUD simply because their anxiety level drops. That emotional “peace factor” is a legitimate part of the decision-making process.
3. The “I had a clot, now what?” experience
There are also real storiessome shared on health forums and patient advocacy sitesof people who developed a clot while on combined birth control. For them, the conversation changes dramatically. The focus moves from “Is this pill right for me?” to “How do I protect myself going forward?”
Many describe a combination of fear, anger, and grief: fear of another clot, anger that they weren’t warned more clearly, and grief over losing a method that controlled their cycles or symptoms so well. Follow-up care typically involves:
- Stopping estrogen-containing methods immediately.
- Completing anticoagulation treatment as directed.
- Switching to a progestin-only or non-hormonal method if contraception is still needed.
- Monitoring for any signs of recurrent clots.
What people often say helped them most afterward was being listened to. Having a clinician acknowledge that their experience was scary and that future choices must be more cautious can be deeply validating.
4. The “I want control, but I also want safety” balancing act
Finally, there are those who never have a clot, but live with low-level anxiety about the risk. They might set reminders to check their legs for swelling, or they might worry every time a calf muscle twinges after a workout. Others shift to non-estrogen methods even without a major risk factor simply to quiet that background stress.
Across these experiences, a few themes keep coming up:
- Clear information lowers anxiety more than vague reassurances.
- Shared decision-makingwhere the clinician and patient talk through options as partnersfeels much better than being told, “Just take this, you’ll be fine.”
- Knowing the warning signs of a clot helps people feel prepared instead of powerless.
If you’re currently deciding whether to start, stop, or switch birth control because of clot concerns, you’re not being “dramatic.” You’re doing exactly what you’re supposed to do: weighing benefits and risks for your life, your health, and your peace of mind.
The Bottom Line
So, can taking birth control increase your risk of blood clots? Yesespecially if the method contains estrogen, and especially if you already have other risk factors. But for many healthy people, the absolute risk remains low, and the benefitseffective pregnancy prevention, lighter periods, improved cramps, acne controlcan be significant.
The key is to avoid one-size-fits-all answers. Instead, work with your clinician to:
- Map out your personal risk factors.
- Compare different birth control optionscombined, progestin-only, and non-hormonal.
- Learn the warning signs of blood clots so you can act quickly if needed.
Your blood is supposed to flow like well-managed city traffic, not a permanent traffic jam. With the right information and a thoughtful plan, you can choose birth control that protects both your fertility goals and your long-term health.