Supplements to Avoid With Eliquis, Warfarin, and Xarelto (Plus What's Safe)

This article is for informational purposes only and does not replace medical advice. Consult your doctor or pharmacist before starting, stopping, or changing any supplement while on blood thinners.

Several common supplements can raise bleeding risk when combined with blood thinners like warfarin, Eliquis, or Xarelto. The ones to watch: ginkgo biloba, garlic supplements, vitamin E above 400 IU, turmeric/curcumin, and fish oil at high doses. St. John's wort works the other way: it can make some blood thinners work less well. Some supplements have no listed interaction.

Why blood thinners and supplements interact

Blood thinners work by slowing your body's clotting process. Warfarin blocks vitamin K, which your body needs to form clots. Newer blood thinners like Eliquis (apixaban) and Xarelto (rivaroxaban) inhibit specific clotting factors directly. Plavix (clopidogrel) prevents platelets from sticking together.

Any supplement that also thins the blood, interferes with clotting factors, or changes how your body processes these drugs can tip the balance. The result: either too much blood thinning (bleeding risk) or too little (clotting risk).

This is not a "maybe it matters" situation. The NIH Office of Dietary Supplements says some supplements "can increase the risk of bleeding" and can interact with medicines "in ways that might cause problems." Its first example is vitamin K, which "can reduce the ability of the blood thinner warfarin to prevent blood from clotting."

Supplements to avoid or use with extreme caution

Each of these carries a bleeding or interaction warning from a drug label, a regulator, NIH or published research, though the evidence varies. Do not add any of them to a blood thinner without your doctor's OK.

Fish oil / omega-3 fatty acids

Fish oil can have an antiplatelet effect at high doses, and the honest version is more mixed than most lists suggest. The NIH Office of Dietary Supplements says doses of 2 to 15 g/day of EPA and/or DHA might increase bleeding time by reducing platelet aggregation, and that fish oil might prolong clotting times when taken with warfarin. The same fact sheet then reports that most research indicates doses of 3 to 6 g/day do not significantly affect the anticoagulant status of patients taking warfarin, and that a 2014 review concluded omega-3s do not affect the risk of clinically significant bleeding. What it does not drop is monitoring. The fact sheet points to the package inserts for prescription omega-3s, and the current Lovaza label says the longer bleeding time seen in some trials "has not exceeded normal limits and did not produce clinically significant bleeding episodes." The same label says patients taking it with "an anticoagulant or other drug affecting coagulation (e.g., anti-platelet agents) should be monitored periodically." Treat fish oil as something to clear with your doctor or pharmacist, and call your doctor right away about unusual bruising or other signs of bleeding.

For timing details on fish oil specifically, see our guide on fish oil: morning or night.

Vitamin E (above 400 IU)

The NIH fact sheet on vitamin E says vitamin E can inhibit platelet aggregation, and that large doses taken with anticoagulant or antiplatelet medicines, such as warfarin, can increase the risk of bleeding. How much it takes is not settled: "The amounts of supplemental vitamin E needed to produce clinically significant effects are unknown but probably exceed 400 IU/day." A meta-analysis in the Annals of Internal Medicine also linked high-dose vitamin E to increased all-cause mortality. Unless your doctor has specifically prescribed high-dose vitamin E, ask your doctor or pharmacist before taking more than 400 IU.

Ginkgo biloba

The National Center for Complementary and Integrative Health (NCCIH) says ginkgo may increase the risk of bleeding in people taking anticoagulant drugs such as warfarin. The warfarin label names ginkgo biloba and garlic as herbal products that may cause bleeding on their own, with effects expected to add to warfarin's. Do not add ginkgo to any blood thinner without your doctor's OK.

Garlic supplements (concentrated)

The concern is garlic supplements, not garlic in your cooking. NCCIH says taking garlic supplements may increase the risk of bleeding, and that people who take anticoagulants or aspirin should talk with their health care provider before using them.

Turmeric / curcumin (high-dose supplements)

A 1985 animal and lab study in Thrombosis Research reported an antithrombotic effect of curcumin. That shows a mechanism, not a measured bleeding risk in people. The evidence of an interaction in people comes from case reports. In 2018, New Zealand's medicines regulator, Medsafe, described a patient on warfarin whose INR rose to over 10 within a few weeks of starting a turmeric product, and warned that turmeric/curcumin products "can interact with warfarin". It also said that using these products with medicines that affect bleeding, such as anticoagulants and antiplatelets, "should be avoided". A 2014 case report describes a raised INR in a patient who took turmeric with fluindione, a blood thinner that works like warfarin. Small studies point the other way: a 10-day study of a curcumin product found no significant change in INR in 14 people on warfarin, and a trial in healthy volunteers with 3-week treatment phases found no clinically relevant effect on platelet or clotting tests, alone or with aspirin. Turmeric in food is a different thing from a concentrated curcumin capsule, and Medsafe says its warning does not apply to turmeric used in food. Do not add a turmeric or curcumin supplement to a blood thinner without your doctor's OK. If you take warfarin, the warfarin label calls for more frequent INR checks when you start or stop any botanical.

Other supplements to check first

• Ginger supplements (concentrated capsules, not kitchen ginger): a 2022 review called the evidence on bleeding risk conflicting.
• Dong quai: a 1999 case report describes a woman on warfarin whose INR more than doubled after 4 weeks of dong quai. The herb contains natural coumarin compounds, though the authors say the mechanism is unknown.
• Feverfew: NCCIH says it may slow blood clotting and should be stopped at least 2 weeks before scheduled surgery.
• St. John's wort: the problem runs the other way. The Eliquis and Xarelto labels say to avoid it because it lowers how much drug reaches your blood, which the Xarelto label says may raise the risk of clots. The warfarin label says it may decrease warfarin's effect.

Pillo has a Drug-Drug Interaction Checker on its paid plan for looking up whether your medications interact with each other. Treat it as a lookup, not as clearance from your pharmacist.

The warfarin-specific vitamin K rule

You do not need to avoid vitamin K. You need to keep your vitamin K intake consistent from day to day.

Warfarin works by blocking vitamin K's role in the clotting process, and the warfarin Medication Guide says some foods and drinks can "affect your treatment and dose." If you suddenly eat a lot more leafy greens or start a vitamin K supplement, your INR can drop and your blood clots more easily. If you suddenly stop eating greens, your INR can rise, and so can your bleeding risk.

The fix: eat roughly the same amount of vitamin K-rich foods each week. Do not start or stop vitamin K supplements without telling your doctor.

This rule does not apply to Eliquis, Xarelto, or Plavix. The Eliquis and Xarelto labels say vitamin K is not expected to affect how those drugs work, and the Plavix label does not mention vitamin K at all.

CoQ10 and warfarin

The warfarin label lists co-enzyme Q10 among the herbal products that may decrease warfarin's effect, and NCCIH says CoQ10 may interact with warfarin. If you take warfarin and want to add CoQ10, tell your doctor so they can monitor your INR more closely during the transition.

What the warfarin vitamin K rule does not mean for Eliquis or Xarelto

The rule above is a warfarin rule. If your blood thinner is Eliquis (apixaban) or Xarelto (rivaroxaban), it is not your rule, and both labels say why.

Both drugs are factor Xa inhibitors. Warfarin works by interfering with vitamin K's role in clotting; these two do not. Each label states it plainly in its bleeding section: protamine sulfate and vitamin K "are not expected to affect the anticoagulant activity of apixaban", and the Xarelto label says the same for rivaroxaban. Those sentences describe vitamin K given as an emergency reversal agent rather than vitamin K on your dinner plate, but the underlying point is the one you came for: the effect of these drugs does not run through vitamin K.

There is a second difference. On warfarin, the INR blood test is your safety net, so if a supplement nudges your clotting, a lab draw can catch it. On Eliquis, the label takes that net away: changes in clotting tests such as PT, INR and aPTT at the usual dose are small, vary a lot, and are "not useful in monitoring the anticoagulation effect of apixaban." The familiar advice to watch your INR after adding a supplement has nothing to watch here. So tell your doctor before you add one. The Eliquis Medication Guide asks you to tell your doctor about all the vitamins and herbal supplements you take.

The labels do name one supplement, and it runs in the opposite direction from what most people assume: St. John's wort. Both list it among the enzyme inducers to avoid because it lowers how much drug reaches your bloodstream. The risk there is a clot, not a bleed.

Can you take magnesium with Eliquis?

Neither label lists a magnesium supplement as an interaction. Magnesium shows up in both as magnesium stearate, an inactive ingredient in the tablet itself. The only other mention, and the closest thing to a test, sits in the Xarelto label's pharmacology section, where an antacid containing aluminum hydroxide and magnesium hydroxide "did not show an effect on the bioavailability and exposure of rivaroxaban". That was an antacid, not a magnesium supplement, so treat it as a hint rather than an answer. NIH's Office of Dietary Supplements lists magnesium's medication interactions as oral bisphosphonates, tetracyclines, and quinolone antibiotics, plus diuretics and proton pump inhibitors that can affect magnesium status. Anticoagulants are not on that list. Not listed is not the same as studied and cleared, so tell your prescriber before you start.

Can you take fish oil with Eliquis?

Neither label names fish oil or omega-3s. The Office of Dietary Supplements says fish oil "can have antiplatelet effects at high doses, although it appears to be less potent than aspirin", and notes that the authors of a 2014 review "concluded that omega-3s do not affect the risk of clinically significant bleeding". The catch is that this guidance is written around warfarin, where the follow-up step is to recheck your INR. On Eliquis there is no INR to recheck. The dose-related picture is in the fish oil section above.

Can you take vitamin D with Eliquis?

Neither label names vitamin D. The Office of Dietary Supplements lists vitamin D's medication interactions as orlistat, statins, steroids, and thiazide diuretics, and anticoagulants are absent from that list. The version people actually ask about is a combined D3 + K2 product. Eliquis does not work through vitamin K, so the warfarin rule about keeping vitamin K steady does not carry over to the K2 half. Our guide on vitamin D and K2 together covers when the combination makes sense.

None of this replaces a check with the person who prescribed your blood thinner. Consult your doctor or pharmacist for advice specific to your medications.

Magnesium and blood thinners

Is magnesium a blood thinner?

No, not the way warfarin, Eliquis or Xarelto are. Studies find magnesium does little to the clotting system itself. Its effect is on platelets, and the clearest results came from magnesium given by IV.

In one lab study, researchers added magnesium to blood from volunteers. Below 3 mmol/L they saw no significant effect. Above that they saw only small changes, which they called "unlikely to be clinically important" (British Journal of Anaesthesia, 1995). Normal blood magnesium is 0.75 to 0.95 mmol/L, per NIH.

In 14 healthy men given magnesium by IV, bleeding time rose 48% and their platelets clumped less (Thrombosis and Haemostasis, 1996). A 2001 follow-up found IV magnesium did not change blood markers of clotting. It pointed to platelets as the source (Blood Coagulation & Fibrinolysis, 2001). One trial gave magnesium oxide tablets for 3 months to 42 heart patients already taking aspirin. A lab measure of platelet-driven clotting dropped 35% compared with placebo, though platelet clumping tests did not change significantly (American Journal of Cardiology, 1999).

These studies, in healthy volunteers or heart patients on aspirin, do not show how magnesium adds to warfarin, Eliquis or Xarelto. That is one more reason to tell your prescriber before you start.

Does magnesium affect warfarin?

The warfarin label mentions magnesium only as magnesium stearate, an inactive ingredient in the tablet. But it flags something magnesium can cause. Diarrhea is first on its list of factors that "may be responsible for increased INR response." The label also counts a high INR (above 4.0) as a risk factor for bleeding. NIH says high doses of magnesium from supplements or medicines "often result in diarrhea" (Office of Dietary Supplements). The warfarin Medication Guide says to call your healthcare provider right away if you "are sick with diarrhea." Our guide on how long magnesium diarrhea lasts covers what to change.

The same label says to tell your doctor about all the medicines you take, "including prescription and over-the-counter medicines, vitamins, and herbal supplements." If your pharmacist asks you to take magnesium at a different time of day from warfarin, Pillo can give each one its own alarm.

Does the type of magnesium matter?

Per NIH, the aspartate, citrate, lactate and chloride forms tend to be absorbed better than oxide and sulfate. Carbonate, chloride, gluconate and oxide are the forms most often reported to cause diarrhea (Office of Dietary Supplements). Glycinate is not one of the forms the fact sheet compares. Our guide to magnesium glycinate vs citrate vs oxide goes through each form.

One "magnesium" product is different. Doan's back pain caplets contain magnesium salicylate, an NSAID pain reliever in the same family as aspirin. Its Drug Facts label warns that the chance of severe stomach bleeding is higher if you "take a blood thinning (anticoagulant) or steroid drug" (Doan's Maximum Strength label). Diurex Water Pills contain magnesium salicylate too and carry the same warning. Both labels say to ask a doctor before use if that warning applies to you. They also say to stop use and ask a doctor if you feel faint, vomit blood, have bloody or black stools, or have stomach pain that does not get better. The warfarin label lists NSAIDs among drugs that can raise bleeding risk. If a pain reliever or water pill says magnesium on the box, check the active ingredient.

Who needs to be more careful with magnesium?

People with kidney disease. NIH says the risk of magnesium toxicity "increases with impaired renal function or kidney failure" (Office of Dietary Supplements). Our page on signs of too much magnesium lists what that looks like. The warfarin label also asks for more frequent INR checks with reduced kidney function. If you have kidney disease and take a blood thinner, ask before adding any magnesium product, including antacids and laxatives.

Supplements that are generally safe with blood thinners

Not everything is off-limits. We searched the warfarin, Eliquis, Xarelto and Plavix labels and the NIH Office of Dietary Supplements fact sheets for the supplements below, and none of them names these pairs as an interaction. Not listed is not the same as tested and cleared, so check with your doctor or pharmacist before you start. These are the supplements we checked:

Quick reference: the full interaction chart

If you are managing blood thinners plus supplements, setting separate timed reminders helps you keep everything spaced correctly. Pillo's persistent alarm keeps going until you respond, and its dose log records each dose as taken, skipped or late, which helps with the "did I already take that?" question that gets risky with anticoagulants.

What to do before adding any supplement

1. Tell your doctor or pharmacist. This is not optional with blood thinners. Bring the bottle or show them the exact product.
2. Check the interaction. Ask your pharmacist to screen your supplement against your blood thinner before purchasing.
3. Know the bleeding signs. The warfarin, Eliquis, Xarelto and Plavix Medication Guides each say to call your doctor right away about signs of bleeding, such as bleeding that lasts a long time, pink or brown urine, red or black stools, or vomiting blood.
4. Watch your INR (warfarin users). The warfarin label calls for more frequent INR checks when you start or stop another drug, including herbal products. Ask your anticoagulation clinic when your next check should be after you start a new supplement.
5. Do not start or stop a supplement on your own. The warfarin label says not to take or stop herbal or over-the-counter products except on your doctor's advice, and NIH says sudden changes in vitamin K intake can raise or lower warfarin's effect. Warning signs come first: call your doctor right away about bleeding (step 3), and NCCIH says to stop turmeric or curcumin products immediately and talk with your health care provider if you notice liver damage signs such as dark urine or jaundice.

If you also take a statin, the list is different again. We cover which supplements to avoid with statins, and the milligram threshold that decides it, in a separate guide.

FAQ

Can I take fish oil with Eliquis?

The NIH Office of Dietary Supplements says fish oil can have antiplatelet effects at high doses and might prolong clotting times when taken with warfarin. The same fact sheet also reports that most research indicates doses of 3 to 6 g/day do not significantly affect the anticoagulant status of patients taking warfarin, and that a 2014 review concluded omega-3s do not affect the risk of clinically significant bleeding. What it keeps is a monitoring step. The current Lovaza label, for a prescription omega-3, says patients taking it with "an anticoagulant or other drug affecting coagulation (e.g., anti-platelet agents) should be monitored periodically." As the Eliquis section above explains, INR is not a useful test on Eliquis, so ask what that monitoring should look like for you. Tell your doctor or pharmacist before combining them.

Is turmeric safe with warfarin?

Turmeric in food (curries, golden milk with a pinch of turmeric) is a different question from a concentrated curcumin capsule. For supplements, the evidence of an interaction in people is case reports. New Zealand's regulator Medsafe described a patient on warfarin whose INR rose to over 10 within a few weeks of starting a turmeric product. It warned that these products can interact with warfarin and said using them with blood thinners should be avoided. A small 10-day study of a curcumin product found no significant change in INR in people on warfarin. Talk with your doctor or pharmacist before taking a concentrated curcumin supplement with warfarin. The picture changes when the other drug is an anti-inflammatory rather than a blood thinner, which is what turmeric and meloxicam works through.

Do I need to avoid all vitamin K on warfarin?

No. The goal is consistency, not avoidance. Eat roughly the same amount of vitamin K each week. NIH says sudden increases or decreases in vitamin K intake can increase or decrease warfarin's effect. Do not start or stop K supplements without talking to your doctor.

Can I take magnesium with blood thinners?

Neither the Eliquis nor the Xarelto label lists a magnesium supplement as an interaction, and the NIH Office of Dietary Supplements fact sheet on magnesium names oral bisphosphonates, tetracyclines, quinolone antibiotics, diuretics and proton pump inhibitors as the medication interactions to know, without naming anticoagulants. Not listed is not the same as studied and cleared, so raise it with your doctor or pharmacist before you start. See our full guide on magnesium timing.

Can I take magnesium with Eliquis?

The Eliquis label does not list a magnesium supplement as an interaction, and magnesium appears in it only as magnesium stearate, an inactive tablet ingredient. NIH's Office of Dietary Supplements names oral bisphosphonates, tetracyclines, quinolone antibiotics, diuretics, and proton pump inhibitors as magnesium's medication interactions, and anticoagulants are not among them. The Eliquis label says clotting tests such as INR are not useful for monitoring it, so tell your prescriber or pharmacist before starting magnesium.

What about a daily multivitamin?

None of the blood thinner labels names multivitamins as an interaction, but each one says to tell your doctor about all the vitamins and herbal supplements you take. NIH says most multivitamins contain vitamin K, "typically at values less than 75% of the daily value (DV)." The DV is 120 mcg. NIH also says people on warfarin "need to maintain a consistent intake of vitamin K from food and supplements" (Office of Dietary Supplements). Taking the same multivitamin every day keeps its share of that intake steady. Check the label for vitamin E content and make sure it is under 400 IU. Avoid multivitamins with added herbal blends that may include ginkgo, garlic, or ginger extracts.

Should I stop all supplements before surgery?

A 2022 review of supplements and bleeding says it is "best to discontinue nonessential supplement use 2 weeks prior to surgery." Ask your surgeon which of yours count as nonessential, and do not stop a vitamin K supplement on warfarin without your doctor, for the reason in the steps above. Your blood thinner management around surgery is a separate decision your doctor will handle. Always provide a complete list of everything you take, including supplements.

Related guides:

• Supplement timing chart: when to take each vitamin
• Which vitamins should not be taken together
• Fish oil: morning or night?
• Best time to take magnesium
• Can you take too much vitamin D?
• Missed dose of Eliquis
• Missed dose of warfarin
• Missed dose of Xarelto
• Missed blood thinner and stroke risk
• Supplements and antidepressants: which mix safely

If remembering doses is the hard part, the Pillo medication reminder app can take that job off your plate.

This article is for informational purposes only. It is not medical advice. Consult your doctor or pharmacist before starting, stopping, or changing any supplement while taking blood thinners.

Reviewed under our Medical Review Policy.