Heavy Menstrual Bleeding on Blood Thinners: What Works and What to Ask Your Doctor

When you start taking a blood thinner-whether it’s for a blood clot, atrial fibrillation, or a replaced heart valve-you’re not just signing up for protection against stroke or pulmonary embolism. You’re also signing up for a possible side effect that no one talks about until it’s already wrecking your life: heavy menstrual bleeding.

One in every two women on blood thinners will suddenly find themselves changing pads or tampons every 30 minutes. Some bleed through clothes. Others end up in the ER. And most of them? Their doctor never asked.

This isn’t rare. It’s common. And it’s not normal.

Why Blood Thinners Make Periods So Much Heavier

Anticoagulants don’t just thin your blood to prevent clots-they also make it harder for your uterus to stop bleeding during your period. That’s because menstrual bleeding relies on a delicate balance of clotting factors, and blood thinners disrupt that balance.

Studies show that 66% to 70% of menstruating women on oral anticoagulants develop heavy menstrual bleeding (HMB) within months of starting treatment. That’s more than double the baseline rate in the general population, which is around 10% to 30%.

It’s not just about volume. It’s about disruption. Women report needing to carry emergency changes everywhere. Missing work. Avoiding dates. Waking up terrified of leaking in the middle of the night. One woman on Reddit said she stopped going to the gym because she couldn’t risk a leak during a spin class. Another said she cried in the bathroom at work because she’d soaked through three tampons in two hours.

This isn’t "minor bleeding." The National Blood Clot Alliance calls it "patient-relevant bleeding"-because while it won’t kill you, it can make you feel like your life is on hold.

Not All Blood Thinners Are Created Equal

If you’re on a blood thinner and your periods have gotten worse, the type you’re taking might be part of the problem.

Research shows that rivaroxaban carries the highest risk of heavy bleeding. Women on this drug are more likely to need emergency care or hospitalization for menstrual bleeding than those on other options.

On the other hand, apixaban and dabigatran are linked to significantly lower rates of HMB. One study found that switching from rivaroxaban to apixaban reduced bleeding episodes by over 50% in women who had previously struggled with severe periods.

Warfarin? It’s also a risk-especially if your INR levels aren’t tightly controlled. But even then, the bleeding pattern tends to be more unpredictable than with the newer drugs.

Here’s what you need to know: your anticoagulant isn’t just about preventing clots. It’s also about how it affects your body every 28 days. If your periods have become unbearable, asking your doctor about switching isn’t giving up on your treatment-it’s optimizing it.

The First-Line Treatment: Hormonal Options That Work

Before you think about stopping your blood thinner (don’t), there’s a proven solution that doesn’t interfere with clot prevention: hormonal therapy.

The most effective option? The levonorgestrel intrauterine system-better known as the Mirena or Kyleena IUD. It releases a low dose of progesterone directly into the uterus, thinning the lining so there’s less tissue to shed. In clinical trials, it reduces menstrual blood loss by 70% to 90% within six months. Many women report periods stopping altogether.

And here’s the best part: you can keep taking your blood thinner while using it. No interaction. No increased risk of clots. Just less bleeding.

Other hormonal options include:

• Progestin implants (like Nexplanon)-inserted under the skin, effective for up to three years.
• Oral progestins like norethisterone (5 mg three times a day for 21 days per cycle)-used for short-term control during heavy episodes.
• Combined hormonal contraceptives (pill, patch, ring)-safe to use with most anticoagulants and can reduce bleeding by 40% or more.

These aren’t experimental. They’re backed by the American Society of Hematology and the American College of Obstetricians and Gynecologists. Yet, a 2023 survey found that 68% of women on anticoagulants said their hematologist never asked about their periods.

Tranexamic Acid: The Non-Hormonal Option

If you don’t want hormones-or can’t use them-there’s another option: tranexamic acid.

This medication works by helping your blood form clots right where it’s needed: in the uterus. You take it only during your period, usually 1 to 2 grams every 8 hours for up to five days.

Studies show it reduces bleeding by 30% to 50%. It’s not as powerful as the IUD, but it’s effective, non-hormonal, and doesn’t interfere with anticoagulants when taken correctly.

Important note: Don’t take tranexamic acid with NSAIDs like ibuprofen or aspirin. Both increase bleeding risk, and combining them with anticoagulants can be dangerous. Always check with your doctor before mixing any new meds.

What Doesn’t Work (and Why)

Some women try to manage HMB by skipping doses of their blood thinner. That’s a recipe for disaster.

Research shows that skipping or shortening anticoagulant treatment increases the risk of recurrent blood clots by up to five times. That’s not a risk worth taking.

Endometrial ablation-surgery to burn off the uterine lining-is sometimes suggested for heavy periods. But for women on blood thinners, it’s risky. The procedure can cause serious bleeding, and you’ll still need to stay on anticoagulants afterward. Plus, you’ll need to use birth control forever after the procedure, since pregnancy becomes dangerous.

NSAIDs like ibuprofen? They can reduce bleeding by 20% to 40% in some women. But if you’re already on a blood thinner, adding NSAIDs increases your bleeding risk. Use them only under strict medical supervision.

What to Do If Your Doctor Doesn’t Know

Here’s the hard truth: most hematologists aren’t trained in gynecology. Most gynecologists aren’t trained in anticoagulation. So you’re stuck in the middle.

Don’t wait for them to ask. Bring it up.

Use these exact phrases:

• "Since starting my blood thinner, my periods have become unbearable. I’m changing pads every 30 minutes and missing work. Is this normal?"
• "I’ve read that apixaban causes less heavy bleeding than rivaroxaban. Could we consider switching?"
• "Can you refer me to a gynecologist who understands anticoagulation? I’d like to explore the IUD option."

Print out the 2024 American Society of Hematology guidelines on menstrual bleeding in anticoagulated women. Bring them to your appointment. Most doctors will appreciate the initiative.

If your doctor dismisses you, find a new one. This isn’t normal. And you deserve better.

The Bigger Picture: Why This Matters

One in five women stop taking their blood thinner within the first year because of heavy bleeding. That’s not just a side effect-it’s a treatment failure.

When women stop their anticoagulants, they’re not just risking a clot. They’re risking stroke, pulmonary embolism, or death.

But if we can manage the bleeding? They can stay on the medication that saves their life-and still have a life worth living.

The National Blood Clot Alliance now recommends that all women of reproductive age be told about the risk of heavy bleeding before starting anticoagulants. That’s a step forward. But it’s still not standard practice.

And the guidelines? They’re coming. A joint statement from the American Society of Hematology and ACOG is expected in mid-2025. But you don’t have to wait. You can act now.

Heavy periods on blood thinners aren’t something you just have to live with. They’re a treatable side effect. And you don’t have to suffer in silence.

What to Ask Your Doctor

Here’s a simple checklist to take to your next appointment:

1. Is my current anticoagulant likely to be causing my heavy bleeding?
2. Would switching to apixaban or dabigatran reduce my bleeding?
3. Can I safely use a levonorgestrel IUD while on my current medication?
4. Should I be tested for iron deficiency or anemia?
5. Is tranexamic acid an option for me?
6. Can you refer me to a gynecologist who specializes in anticoagulated patients?

If your doctor can’t answer these, it’s time to find someone who can.