Herb & supplement monograph

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

But these pages have grown well beyond that into a full monograph — what Broccoli 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

Check Broccoli against your medication

Add one medication

✓ Supplement

Broccoli

1 Your medication

Start typing any prescription or over-the-counter drug name.

Reviewed by licensed pharmacists Sourced from Natural Medicines

On this page

Broccoli 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 Broccoli drug interaction appears low for most people eating typical amounts. None of the listed interactions are rated major, and every one rests on a theoretical concern rather than documented harm in people.

Interactions deserving the most attention

The interactions worth the most attention involve medications cleared by two liver enzymes, listed as CYP1A2 substrates and CYP2A6 substrates. Human research shows that eating large amounts of broccoli every day, around 500 grams for about a week, can sharply increase the activity of these enzymes. In theory, that could lower the levels of affected medications and make them work less well, which would matter most for a medicine that depends on steady blood levels. Whether this actually changes how these drugs work in real life has not been confirmed.

What the rest of the list means

The long list of moderate interactions comes almost entirely from these two enzyme pathways, not from many separate proven problems. The concern is theoretical, based on natural compounds in broccoli that may speed up how the body clears certain medications. The enzyme changes were also seen with very large daily servings, well beyond what most people eat.

Check your medications against Broccoli

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

Interaction report

Drugs that interact with Broccoli

187 medications have a known interaction with Broccoli, 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 Broccoli using our pharmacist-reviewed interaction data.

AI summaries are generated from our Broccoli 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 Broccoli 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 Broccoli affects

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

All 2 drug categories Broccoli interacts with

Cytochrome P450 1a2 (cyp1a2) SubstratesCytochrome P450 2a6 (cyp2a6) Substrates

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, broccoli might reduce the levels and effects of drugs metabolized by CYP1A2.
Pharmacokinetic research in humans shows that eating 500 grams of fresh broccoli daily for 6-12 days can increase CYP1A2 activity by 10% to 200%. Induction of CYP1A2 activity by broccoli is attributed to its glucosinolate constituents.

Likelihood Possible Evidence B

Cytochrome P450 2A6 (Cyp2A6) Substrates

Theoretically, broccoli might reduce the levels and effects of drugs metabolized by CYP2A6.
Pharmacokinetic research in humans shows that eating 500 grams of broccoli daily for 6 days increases CYP2A6 activity by 135% to 550%. Induction of CYP2A6 activity is attributed to its glucosinolate constituents.

Likelihood Possible Evidence B

Monograph

Broccoli: Uses, Safety & Side Effects

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

The bottom line

Broccoli is a nutritious cruciferous vegetable rich in fiber, vitamins, and plant compounds like sulforaphane that have drawn scientific interest for health benefits. Eating broccoli as food is safe and healthy for most people, but concentrated supplements and extracts are less studied and benefits are not firmly proven. Talk to your pharmacist or doctor before using broccoli supplements, especially in high doses.

Scientific name: Brassica oleracea var. italica
Family: Brassicaceae
Part used: Florets, sprouts, seeds, and stalks
Common forms: Whole vegetable (fresh, frozen, cooked), broccoli sprouts, powders, capsules, and sulforaphane or glucoraphanin extracts

People commonly use it for

General nutrition and antioxidant support
Heart and digestive health
Detoxification support
Cancer risk reduction (popular interest)
Blood sugar support

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

Safety at a glance

OverallLikely safe

Broccoli as a food is safe for most people; concentrated supplements are less studied.

PregnancyLikely Safe

When used orally in food amounts. There is insufficient reliable information available about the safety of broccoli when used in medicinal amounts dur...

Read the full pregnancy detail

BreastfeedingLikely Safe

When used orally in food amounts. There is insufficient reliable information available about the safety of broccoli when used in medicinal amounts dur...

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.

Jump to a section

Overview

Broccoli is a green vegetable in the cabbage family, the same family as cauliflower, kale, and Brussels sprouts. It is grown around the world and is a common part of many diets. People usually eat the flower-like heads (florets) and stalks, either raw or cooked.

Besides being eaten as food, broccoli is also sold as a supplement. Broccoli sprouts (young broccoli plants) and concentrated extracts of compounds like sulforaphane are sold as powders, capsules, and drinks. These products are marketed for a range of health goals, though they are far less studied than broccoli eaten as a regular food.

How it works

Broccoli contains compounds called glucosinolates. When broccoli is chopped, chewed, or its sprouts are crushed, an enzyme converts a glucosinolate called glucoraphanin into sulforaphane. Sulforaphane is the compound most studied for possible health effects.

In laboratory and animal studies, sulforaphane appears to activate the body's own antioxidant and detoxification pathways and may reduce certain markers of inflammation. Broccoli also provides fiber, vitamins, and other antioxidants that support general health.

It is important to remember that much of this research comes from cells and animals. These findings do not always translate into proven benefits for people.

Effectiveness

Does Broccoli work?

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

Evidence overview · 9 uses evaluated

1 Possibly effective 8 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.

Possibly Effective Colorectal cancer