Herb & supplement monograph

Brussels Sprout 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 Brussels Sprout interacts with medications. The heart of this page is the interaction list — every drug Brussels Sprout is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Brussels Sprout 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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Brussels Sprout Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, most Brussels Sprout drug interactions are moderate in nature, and for most people eating normal amounts the risk of a truly meaningful problem appears low. None of the interactions are rated major, and the documented effects are fairly small drops in medication levels, usually seen only with large daily servings.

Interactions deserving the most attention

The interaction that deserves the most attention involves warfarin. Early human research found that adding a large daily portion of Brussels sprouts sped up the body's clearance of warfarin and lowered its blood levels, which could theoretically weaken its protection against blood clots. Human studies also show that regular daily intake modestly lowers levels of acetaminophen and oxazepam, changes of roughly one sixth that may matter little for occasional use but are worth knowing about with steady dosing.

What the rest of the list means

The long list of interacting medications mostly reflects one shared idea, that Brussels sprouts may speed up body processes that clear certain drugs. Much of this comes from animal or lab research, and the human data we have shows only modest changes at high daily intakes, so most combinations are unlikely to cause a noticeable problem.

Check your medications against Brussels Sprout

Based on HelloPharmacist’s Brussels Sprout interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Brussels Sprout

241 medications have a known interaction with Brussels Sprout, 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 Brussels Sprout using our pharmacist-reviewed interaction data.

AI summaries are generated from our Brussels Sprout 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 Brussels Sprout 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 Brussels Sprout affects

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

All 5 drug categories Brussels Sprout interacts with

Acetaminophen (tylenol, Others)Cytochrome P450 1a2 (cyp1a2) SubstratesGlucuronidated DrugsOxazepam (serax)Warfarin (coumadin)

Acetaminophen (Tylenol, Others)

A cabbage and Brussels sprout-containing diet can increase metabolism and decrease levels of acetaminophen. In clinical research, a diet that includes daily consumption of cabbage and Brussels sprout decreases acetaminophen levels by as much as 16%. This appears to occur due to a boost of elimination through glucuronide conjugation.

Likelihood Probable Evidence B

Cytochrome P450 1A2 (Cyp1A2) Substrates

Animal research suggests that Brussels sprout can induce cytochrome P450 1A2 (CYP1A2) activity. Theoretically, Brussels sprout might increase the clearance and decrease the effects of drugs metabolized by CYP1A2. Some drugs metabolized by CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, zileuton (Zyflo), zolmitriptan (Zomig), and others.

Likelihood Possible Evidence D

Glucuronidated Drugs

A cabbage and Brussels sprout-containing diet seems to boost elimination through glucuronide conjugation. Theoretically, these foods might also lower levels of other drugs that are metabolized through glucuronide conjugation, including acetaminophen (Tylenol, others) and oxazepam (Serax), haloperidol (Haldol), lamotrigine (Lamictal), morphine (MS Contin, Roxanol), zidovudine (AZT, Retrovir), and others.

Likelihood Probable Evidence B

Oxazepam (Serax)

A diet that includes daily consumption of cabbage and Brussels sprout decreases oxazepam levels by as much as 17%. This appears to occur due to a boost of elimination through glucuronide conjugation. Theoretically, Brussels sprout might also lower levels of other drugs that are metabolized through glucuronide conjugation including acetaminophen (Tylenol, others), haloperidol (Haldol), lamotrigine (Lamictal), morphine (MS Contin, Roxanol), zidovudine (AZT, Retrovir), and others.

Likelihood Probable Evidence B

Warfarin (Coumadin)

Preliminary clinical research shows that increasing Brussels sprout consumption by 400 grams daily can increase warfarin clearance rate by 27% and decrease plasma concentrations of warfarin by 16%. Theoretically, consuming Brussels sprout while taking warfarin might decrease the effects of warfarin and increase the risk of blood clots in some people.

Likelihood Possible Evidence B

Monograph

Brussels Sprout: Uses, Safety & Side Effects

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

The bottom line

Brussels sprouts are a nutritious cruciferous vegetable rich in fiber, vitamin C, vitamin K, and plant compounds called glucosinolates. Eating them as part of a balanced diet is healthy and safe for most people, but supplement-style claims (like preventing cancer) are not well proven. If you take blood thinners or have thyroid concerns, talk with your pharmacist or doctor about your intake.

Scientific name: Brassica oleracea var. gemmifera
Family: Brassicaceae
Part used: Edible sprouts (small leafy buds)
Common forms: Fresh or cooked vegetable, frozen, powdered, capsule or extract supplements

People commonly use it for

General nutrition and fiber
Antioxidant support
Digestive health
Heart health support
Cancer-prevention interest

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

Safety at a glance

OverallLikely safe

Generally safe and healthy when eaten as a normal food.

PregnancyInsufficient reliable information

Insufficient reliable information available; avoid amounts in excess of those found in foods.

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid amounts in excess of those found in foods.

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

Brussels sprouts are a green, leafy vegetable that grows on a tall stalk in tight little buds that look like tiny cabbages. They belong to the cruciferous family, which also includes broccoli, cauliflower, kale, and cabbage. They are thought to have been popularized near Brussels, Belgium, which is how they got their name.

People mostly eat Brussels sprouts as a cooked or roasted vegetable. They are valued as a good source of fiber, vitamin C, vitamin K, folate, and natural plant compounds. Some companies also sell cruciferous vegetable extracts in capsule form, but the most common and best-studied way to enjoy them is simply as food.

How it works

Brussels sprouts contain compounds called glucosinolates. When you chop or chew the vegetable, these break down into substances such as sulforaphane and indole-3-carbinol. In laboratory and animal studies, these compounds have shown antioxidant activity and effects on enzymes the body uses to process certain substances.

The vegetable is also high in fiber, which supports digestion, and in vitamins C and K and folate, which the body needs for many normal functions. Vitamin K plays a role in blood clotting.

It is important to know that much of the research on these compounds comes from cell or animal studies. Effects seen in a lab do not always translate to clear health benefits in people.

Effectiveness

Does Brussels Sprout work?

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

Evidence overview · 10 uses evaluated

10 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.

For Brussels Sprout, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 10 conditions — evidence insufficient to rate

Insufficient Reliable Evidence To Rate Benign prostatic hyperplasia (BPH)