Written by Austin Ulrich, PharmD, BCACP | Reviewed by Christina Aungst, PharmD
Published on June 3, 2024

Key takeaways:

Blood thinner medications help prevent and treat blood clots. But they can also increase your risk of bleeding. You shouldn’t combine blood thinners with nonsteroidal anti-inflammatory drugs (NSAIDs). The combination raises your bleeding risk.

Many over-the-counter (OTC) supplements, such as garlic, fish oil, and ginkgo biloba, can also raise your bleeding risk. And St. John’s wort may make your blood thinner less effective. Check with your pharmacist before taking an OTC supplement with your blood thinner.

Blood thinners can also interact with heartburn medications, some antidepressants, and some medications that treat infections. Check with your healthcare team before taking any new medications or OTC products with your blood thinner to make sure it’s safe.

Table of contents
NSAIDs
Heartburn meds
SSRIs
Anti-infection meds
St. John’s wort
Supplements
Ozempic
Bottom line
References

GoodRx Health
Blood thinners are medications that lower your risk of blood clots. They include well-known anticoagulants such as warfarin (Coumadin, Jantoven), apixaban (Eliquis), and rivaroxaban (Xarelto). Antiplatelet medications such as clopidogrel (Plavix), ticagrelor (Brilinta), and aspirin are also blood thinners.

When you’re taking a blood thinner, it’s important to be aware of potential interactions. Your healthcare team can review your prescription medications to keep an eye out for any concerns. But when it comes to over-the-counter (OTC) products, there may be blood thinner interactions you’re not aware of.

In this article, we’ll take a look at six blood thinner interactions you should know about. Keep in mind that this list isn’t comprehensive. So it’s best to check with your pharmacist before purchasing a new OTC product to make sure it’s safe for you. And make sure they have your updated medication list when reviewing any new prescriptions you receive

NSAIDs
Nonsteroidal anti-inflammatory drugs (NSAIDs) are medications that treat fever, swelling, and pain. Common OTC NSAIDs include ibuprofen (Advil, Motrin) and naproxen (Aleve). NSAIDs are common ingredients in OTC products for migraines and menstrual cramps. They’re also often included in products for upset stomach (more on this next), sleep, and cold or flu symptoms. Examples include:

Advil Cold and Sinus (ibuprofen / pseudoephedrine)

Goody’s Extra Strength Headache Powder (acetaminophen / aspirin / caffeine)

Excedrin Migraine (acetaminophen / aspirin / caffeine)

Pamprin Max Pain + Energy (aspirin / acetaminophen / caffeine)

Motrin PM (ibuprofen / diphenhydramine)

Aleve PM (naproxen / diphenhydramine)

Excedrin PM (aspirin / acetaminophen / diphenhydramine)

Aleve-D Sinus and Cold (naproxen / pseudoephedrine)

Alka-Seltzer Plus Cold (aspirin / chlorpheniramine / phenylephrine)

NSAIDs aren’t blood thinners. But they can raise your risk of bleeding. And this risk goes up if they’re combined with blood thinners. So it’s best to avoid this combination. Talk to your prescriber or pharmacist about a safer treatment option that won’t interact with your blood thinner.

Be sure to read OTC labels carefully to check for any NSAIDs. And if you’re unsure if a product contains an NSAID, check with your pharmacist before taking it.

Good to know: Aspirin is also an NSAID, so you should avoid taking it for pain or fever if you take a blood thinner. But in some cases, your prescriber may recommend low-dose aspirin (usually 81 mg) along with your blood thinner medication. This combination isn’t appropriate for everyone. So you should only take aspirin daily if your prescriber tells you to.

Is it safe to take acetaminophen (Tylenol) with blood thinners?
Generally, yes — unless you’re taking warfarin. Acetaminophen doesn’t seem to raise your risk of bleeding or interact with most blood thinners. But it can boost warfarin’s effects in some cases, which can raise your risk of bleeding. Acetaminophen also has other risks to consider. So it’s best to check with your healthcare team to make sure it’s safe before taking it.

GoodRx iconEXPERT PICKS: WHAT TO READ NEXT
Blood thinner 101: Learn the difference between antiplatelet and anticoagulant medications, two types of blood thinners.

Warfarin and your diet: You don’t have to give up spinach if you’re taking warfarin. But you do need to follow these tips to prevent it from affecting your medication.

NSAIDs and blood thinners: These two medications should not be taken at the same time. Here’s why.

Upset stomach and heartburn medications
Certain OTC medications for upset stomach or heartburn can also raise your risk of bleeding when combined with blood thinners.

Some products cause a blood thinner interaction because they contain an NSAID or a salicylate (a product like aspirin). Examples include:

Alka-Seltzer (citric acid / aspirin / sodium bicarbonate)

Pepto-Bismol (bismuth subsalicylate)

Kaopectate (bismuth subsalicylate)

Other OTC medications can raise or lower certain blood thinner levels in your body. Cimetidine (Tagamet), a histamine-2 (H2) blocker for reflux, can raise warfarin levels in the body. This increases your risk of bleeding.

Omeprazole (Prilosec), a proton pump inhibitor (PPI), can also raise warfarin levels if they’re combined. But it has the opposite effect on the antiplatelet medication clopidogrel. Omeprazole and other PPIs can prevent the activation of clopidogrel in your body, making it less effective. This can raise your risk of new or worsening blood clots.

Your healthcare team can recommend a safer option for your symptoms if you take a blood thinner. This may include medications such as Tums (calcium carbonate) or Rolaids (calcium carbonate / magnesium hydroxide).

SSRI antidepressants
Selective serotonin reuptake inhibitors (SSRIs) are a common type of prescription antidepressant. Examples include sertraline (Zoloft), fluoxetine (Prozac), and paroxetine (Paxil).

Like NSAIDs, SSRIs can raise your risk of bleeding. And the risk goes up if they’re combined with blood thinners. In most cases, it’s still OK to take these medications together. But you should keep an eye out for any signs of minor bleeding, such as bleeding gums when brushing your teeth. And seek emergency care if more serious bleeding occurs, such as blood in your urine or stool or a nosebleed that won’t stop.

Anti-infection medications
Some antibiotic and antifungal medications that fight infections can interact with blood thinners. Examples include:

Ketoconazole

Fluconazole (Diflucan)

Itraconazole (Sporanox)

Erythromycin (Ery-Tab, E.E.S.)

Clarithromycin (Biaxin XL)

These medications can raise the levels of warfarin, direct-acting oral anticoagulants (DOACs), and ticagrelor in the body, which increases your bleeding risk. But the same medications can lower clopidogrel levels if combined, which raises your risk of blood clots.

If you have an infection, let your prescriber know you’re taking a blood thinner. They can decide on the best course of treatment for you.

Good to know: This interaction isn’t an issue with topical antifungal products. They don’t absorb into the bloodstream enough to cause an issue. So it’s safe to use these products if you’re taking a blood thinner.

St. John’s wort
St. John’s wort is another common OTC supplement that people may take for depression symptoms. But it’s also notorious for having many interactions. St. John’s wort can lower warfarin levels, which increases your risk of blood clots. It may also lower the levels of DOACs, such as apixaban and rivaroxaban.

It’s best to avoid St. John’s wort if you’re taking a blood thinner. Talk to your prescriber about a safer option to treat your depression symptoms.

Other supplements such as fish oil
It’s common to forget that “natural” products can cause drug interactions. But many herbal supplements and vitamins can interact with blood thinners. Supplements that can raise your risk of bleeding if they’re combined with blood thinners include:

Garlic

Ginkgo biloba

Ginseng

Turmeric

Ginger

Vitamin E

Evening primrose

Omega-3 and fish oil supplements

Eating moderate amounts of these products in food isn’t likely to cause an issue. Most interactions occur if you eat large amounts or take them in supplement form. It’s best to check with your pharmacist before adding any supplements to your routine if you’re taking a blood thinner.

Can you take blood thinners with Ozempic?
Yes, as long as your other medications are also safe to take with Ozempic (semaglutide). There haven’t been any interactions reported with Ozempic and blood thinners. But Ozempic does have other interactions to be aware of, including some medications that treat Type 2 diabetes. And it can affect the absorption of some oral medications. So it’s best to check with your healthcare team to make sure it’s safe for you.

Keep in mind that Ozempic and other similar medications for weight loss can reduce how much you eat. And if you’re taking warfarin, your diet can affect your drug levels. So be sure to let your prescriber know if you’re eating less than usual. They can check to make sure your warfarin levels stay within a safe range.

The bottom line
When you’re taking a blood thinner, it’s important to be aware of potential interactions. You should avoid taking nonsteroidal anti-inflammatory drugs (NSAIDs) with blood thinners. The combination can increase your risk of bleeding. Be aware that NSAIDs are often found in over-the-counter (OTC) cold and flu products and some products for an upset stomach.

Several OTC supplements, such as fish oil, ginkgo biloba, and garlic, can also raise your bleeding risk. And St. John’s wort may make your blood thinner less effective. Check with your prescriber before adding a supplement to your routine.

Prescription medications that can interact with blood thinners include some antidepressants, antibiotics, and antifungal medications. Be sure to let your prescriber know you’re taking a blood thinner if you’re starting a new medication. This can help them choose a safe option for you.

References
Abebe, W. (2019). Review of herbal medications with the potential to cause bleeding: Dental implications, and risk prediction and prevention avenues. The EPMA Journal.

Di Minno, A., et al. (2017). Old and new oral anticoagulants: Food, herbal medicines and drug interactions. Blood Reviews.

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