Herb & supplement monograph

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

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

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the quality of the available evidence, the overall risk of a clinically significant Sulforaphane drug interaction appears low for most people. Although the interaction list is long and every entry carries a moderate rating, all of it rests on lab and animal research, and none of these effects has been reported in humans.

Interactions deserving the most attention

The interactions closest to mattering involve medicines cleared by certain liver enzymes. Sulforaphane may slow the enzymes that process CYP3A4 substrates and CYP2E1 substrates, which could in theory raise the levels of those medicines. For CYP1A2 substrates, the evidence points both ways, since sulforaphane may block that enzyme while a related compound from the same vegetables may boost it. None of this has been confirmed in people, so no single medication stands out as a proven concern.

What the rest of the list means

The long list mostly reflects how many medications pass through these three enzymes, not documented harm from taking them with sulforaphane. Every listed interaction is theoretical, based on possible effects on enzymes the body uses to clear medications, and none of these predicted changes has been seen in humans so far.

Check your medications against Sulforaphane

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

Interaction report

Drugs that interact with Sulforaphane

724 medications have a known interaction with Sulforaphane, 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 Sulforaphane using our pharmacist-reviewed interaction data.

AI summaries are generated from our Sulforaphane 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 Sulforaphane 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 Sulforaphane affects

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

All 3 drug categories Sulforaphane interacts with

Cytochrome P450 1a2 (cyp1a2) SubstratesCytochrome P450 2e1 (cyp2e1) SubstratesCytochrome P450 3a4 (cyp3a4) Substrates

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, sulforaphane might alter the levels and clinical effects of CYP1A2 substrates.
Animal and in vitro research shows that sulforaphane inhibits CYP1A2 enzyme activity. However, its precursor glucoraphanin also appears to increase the expression of the CYP1A2 enzyme, which could lead to increased metabolism of CYP1A2 substrates. These effects have not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, sulforaphane might increase the levels and effects of CYP2E1 substrates.
In vitro evidence shows that sulforaphane inhibits CYP2E1 enzymes. This interaction has not been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, sulforaphane might increase the levels and effects of CYP3A4 substrates.
Animal and in vitro research shows that sulforaphane inhibits CYP3A4 enzyme activity and downregulates its expression. This interaction has not been reported in humans.

Likelihood Possible Evidence D

Monograph

Sulforaphane: Uses, Safety & Side Effects

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

The bottom line

Sulforaphane is a natural compound found in broccoli and other cruciferous vegetables that has shown promising antioxidant and anti-inflammatory effects in lab studies, but strong human evidence for most specific health claims is still limited. It is generally well tolerated as part of a vegetable-rich diet, but if you take a concentrated supplement, talk to your pharmacist or doctor first.

Family: Brassicaceae
Part used: Derived from cruciferous vegetables, especially broccoli sprouts and seeds
Common forms: Capsules, tablets, powders, broccoli sprout extracts, and 'broccoli seed extract' supplements often standardized to glucoraphanin

People commonly use it for

Antioxidant support
General cellular health
Detoxification support
Inflammation
Skin and aging concerns

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

Safety at a glance

OverallUse caution

Sulforaphane from food is considered safe, but concentrated supplements are less studied for long-term use.

PregnancyLikely Safe

When used orally in amounts found in foods. There is insufficient reliable information available about the safety of sulforaphane in medicinal amounts...

Read the full pregnancy detail

BreastfeedingLikely Safe

When used orally in amounts found in foods. There is insufficient reliable information available about the safety of sulforaphane in medicinal amounts...

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

Sulforaphane is a natural sulfur-containing compound found in cruciferous vegetables such as broccoli, broccoli sprouts, cabbage, kale, cauliflower, and Brussels sprouts. Broccoli sprouts and broccoli seeds are especially rich sources.

In the plant, sulforaphane is not present in its active form. Instead, the plant holds a precursor called glucoraphanin, which is converted into sulforaphane by an enzyme called myrosinase when the plant is chopped, chewed, or otherwise damaged.

Today, sulforaphane is popular as a dietary supplement. Many products are made from broccoli seed or sprout extract and are standardized to glucoraphanin. People take it hoping to support antioxidant defenses, general health, and the body's natural detoxification systems.

How it works

Sulforaphane is best known for activating a cellular pathway called Nrf2. In lab studies, turning on this pathway increases the body's own antioxidant and protective enzymes, which may help cells handle stress and harmful molecules.

Researchers have also seen sulforaphane influence inflammation signals and certain detoxification enzymes in laboratory and animal models. Some studies suggest it may affect how cells grow and repair.

It is important to remember that much of this information comes from test-tube and animal research. What happens in a lab dish does not always translate into meaningful benefits in people, so these mechanisms should be seen as proposed explanations rather than proven effects.

Effectiveness

Does Sulforaphane work?

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

Evidence overview · 17 uses evaluated

1 Possibly effective 1 Leans ineffective 15 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 Prostate cancer