Herb & supplement monograph

Vitamin E Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Vitamin E interacts with medications. The heart of this page is the interaction list — every drug Vitamin E is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Vitamin E is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Vitamin E Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Vitamin E drug interaction appears low for most people, especially at typical supplement doses. None of the listed interactions are rated major, and nearly all rest on theoretical or limited evidence rather than well-documented human harm.

Interactions deserving the most attention

The concern with the best support involves bleeding risk. Vitamin E can affect how platelets and clotting factors work, so combining it with warfarin or other anticoagulant or antiplatelet drugs may raise the chance of bleeding, and this effect appears tied to high daily doses. People on chemotherapy should also know there is a theoretical worry that vitamin E's antioxidant action could blunt certain cancer drugs, though the human evidence is unsettled and some researchers argue the opposite. Selumetinib deserves a mention only because the capsules themselves contain vitamin E, which adds to the total dose.

What the rest of the list means

The long list of interacting medications comes mostly from one theoretical mechanism: vitamin E may boost an enzyme the body uses to clear many drugs. That prediction has not been shown to cause meaningful problems in people. Even the cyclosporine concern applies to one special formulation and is considered unlikely with regular vitamin E.

Check your medications against Vitamin E

Based on HelloPharmacist’s Vitamin E interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Vitamin E

766 medications have a known interaction with Vitamin E, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Vitamin E using our pharmacist-reviewed interaction data.

AI summaries are generated from our Vitamin E interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Vitamin E combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Vitamin E affects

Every type of medication (drug category) Vitamin E is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 8 drug categories Vitamin E interacts with

Alkylating AgentsAnticoagulant/antiplatelet DrugsAntitumor AntibioticsCyclosporine (neoral, Sandimmune)Cytochrome P450 3a4 (cyp3a4) SubstratesSelumetinib (koselugo)Warfarin (coumadin)Niacin

Alkylating Agents

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of alkylating agents.
There's concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

Likelihood Possible Evidence D

Anticoagulant/Antiplatelet Drugs

Concomitant use of vitamin E and anticoagulant or antiplatelet agents might increase the risk of bleeding.
Vitamin E seems to inhibit of platelet aggregation and antagonize the effects of vitamin K-dependent clotting factors. These effects appear to be dose-dependent, and are probably only likely to be clinically significant with doses of at least 800 units daily. Mixed tocopherols, such as those found in food, might have a greater antiplatelet effect than alpha-tocopherol. RRR alpha-tocopherol (natural vitamin E) 1000 IU daily antagonizes vitamin K-dependent clotting factors. Advise patients to avoid high doses of vitamin E, especially in people with low vitamin K intake or other risk factors for bleeding.

Likelihood Possible Evidence B

Antitumor Antibiotics

Theoretically, antioxidant effects of vitamin E might reduce the effectiveness of antitumor antibiotics.
There's concern that antioxidants could reduce the activity of antitumor antibiotic drugs such as doxorubicin, which generate free radicals. However, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that might interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin E have on chemotherapy involving antitumor antibiotics. Advise patients to consult their oncologist before using vitamin E supplements, especially in high doses.

Likelihood Possible Evidence D

Cyclosporine (Neoral, Sandimmune)

A specific form of vitamin E might increase absorption and levels of cyclosporine.
There is some evidence that one specific formulation of vitamin E (D-alpha-tocopheryl-polyethylene glycol-1000 succinate, TPGS, tocophersolan, Liqui-E) might increase absorption of cyclosporine. This vitamin E formulation forms micelles which seems to increase absorption of cyclosporine by 40% to 72% in some patients. However, this interaction is unlikely to occur with the usual forms of vitamin E.

Likelihood Unlikely Evidence B

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, vitamin E might induce metabolism of CYP3A4, possibly reducing the levels CYP3A4 substrates.
Vitamin E appears to bind with the nuclear receptor, pregnane X receptor (PXR), which results in increased expression of CYP3A4. Although the clinical significance of this is not known, use caution when considering concomitant use of vitamin E and other drugs affected by these enzymes.

Likelihood Possible Evidence D

Selumetinib (Koselugo)

Taking selumetinib with vitamin E can result in a total daily dose of vitamin E that exceeds safe limits and therefore might increase the risk of bleeding.
Selumetinib contains 48-54 IU vitamin E per capsule. The increased risk of bleeding with vitamin E appears to be dose-dependent. Be cautious when using selumetinib in combination with supplemental vitamin E, especially in patients at higher risk of bleed, such as those with chronic conditions and those taking antiplatelet drugs.

Likelihood Possible Evidence D

Warfarin (Coumadin)

Using vitamin E with warfarin might increase the risk of bleeding.
Due to interference with production of vitamin K-dependent clotting factors, use of more than 400 IU of vitamin E daily with warfarin might increase prothrombin time (PT), INR, and the risk of bleeding,. At a dose of 1000 IU per day, vitamin E can antagonize vitamin K-dependent clotting factors even in people not taking warfarin. Limited clinical evidence suggests that doses up to 1200 IU daily may be used safely by patients taking warfarin, but this may not be applicable in all patient populations.

Likelihood Possible Evidence B

Niacin

Vitamin E might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises high-density lipoprotein (HDL) cholesterol levels in people with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50%. Vitamin E alone combined with a statin does not seem to decrease HDL levels. It is not known whether the adverse effect on HDL is due to one of the other antioxidants or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A

Monograph

Vitamin E: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Vitamin E is an essential fat-soluble vitamin and antioxidant that most people get in adequate amounts from a normal diet. Supplements can help correct a true deficiency, but high-dose vitamin E has not been clearly proven to prevent heart disease or cancer and may carry risks. Talk to your pharmacist or doctor before taking high doses.

Part used: Vitamin E is a nutrient, not a plant part; it is found in plant oils, nuts, seeds, and leafy greens
Common forms: Softgels, capsules, oral liquid, chewable tablets, topical oils and creams

People commonly use it for

General antioxidant support
Skin and hair care
Heart health
Eye health (age-related conditions)
Immune support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Usual dietary amounts are safe, but high-dose long-term supplements may raise the risk of bleeding and other harms.

PregnancyPossibly Safe

When used orally and appropriately. The tolerable upper intake level (UL) during pregnancy is 800 mg for those 14-18 years of age and 1000 mg for thos...

Read the full pregnancy detail

BreastfeedingLikely Safe

When used orally in amounts that do not exceed the tolerable upper intake level (UL). The UL during lactation is 800 mg for those 14-18 years of age a...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

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Overview

Vitamin E is a fat-soluble vitamin that your body needs to work properly. It is actually a group of related compounds, the most active being alpha-tocopherol. Other forms include beta-, gamma-, and delta-tocopherol, along with related compounds called tocotrienols.

Vitamin E is found naturally in many foods, especially vegetable oils (like sunflower and wheat germ oil), nuts, seeds, and green leafy vegetables. Because it is so common in foods, most people who eat a balanced diet get enough without supplements.

People take vitamin E supplements hoping to support heart health, eye health, skin, and the immune system. It is also a popular ingredient in skincare products and topical oils.

How it works

Vitamin E's main job is to act as an antioxidant. It helps protect the fatty parts of your cells, including cell membranes, from damage caused by unstable molecules called free radicals.

It also plays a role in immune function, helps keep blood vessels healthy, and can affect how blood platelets clump together, which is one reason high doses may increase bleeding risk.

Much of what we know about how vitamin E behaves comes from laboratory and animal research. How these effects translate into real-world health benefits in people is still not fully understood.

Effectiveness

Does Vitamin E work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 116 uses evaluated

2 Effective 10 Possibly effective 31 Leans ineffective 73 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Effective Ataxia with vitamin E deficiency (AVED)