Drug & supplement interaction

Cauliflower + Olanzapine

Olanzapine brand name: Zyprexa.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Cauliflower has a moderate interaction with Olanzapine. Preliminary clinical evidence suggests that eating cruciferous vegetables, including broccoli, cauliflower, daikon radish sprouts, and cabbage, can increase cytochrome P450 1A2 (CYP1A2) activity by 14% to 27%.

Read the full interaction report
SeverityModerate
LikelihoodPossible
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cauliflower and Olanzapine

Here is the interaction we found between these two, with the evidence behind it.

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Olanzapine

Olanzapine falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Cauliflower interacts with.

Preliminary clinical evidence suggests that eating cruciferous vegetables, including broccoli, cauliflower, daikon radish sprouts, and cabbage, can increase cytochrome P450 1A2 (CYP1A2) activity by 14% to 27%. Theoretically, cauliflower 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.
Severity Moderate Likelihood Possible Evidence B

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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist: your body relies on a liver enzyme called CYP1A2 to clear olanzapine out of your system. Cruciferous veggies like cauliflower can rev that enzyme up a bit (studies suggest somewhere around a 14% to 27% bump). When that enzyme works faster, olanzapine may get broken down a little quicker, which could slightly weaken how well it controls symptoms like mood swings, agitation, or unusual thinking.

The good news? This is based on limited evidence, and normal food amounts of cauliflower on your plate are unlikely to throw things off. The bigger thing to watch is suddenly eating large, regular quantities (or taking concentrated supplements). If you do, just mention it to your pharmacist or doctor rather than changing anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Peterson S, Schwarz Y, Li SS, et al. CYP1A2, GSTM1, and GSTT1 polymorphisms and diet effects on CYP1A2 activity in a crossover feeding trial. Cancer Epidemiol Biomarkers Prev 2009;18(11):3118-25.

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction 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.
  • PossibleInteraction 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Cauliflower Also Interacts With Other Medications

Cauliflower has 185 moderate known drug interactions in our database — the Olanzapine one above is one of them. If you take anything else, check it against the full list below.

Moderate 185 No known interaction 2,645 (incl. Olanzapine)
Taking anything else?

Check Another of Your Medications Against Cauliflower

Covers the 2,830 medications we’ve checked against Cauliflower. Pick one to open its full report.

From our Q&A

Questions About Cauliflower or Olanzapine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cauliflower or Olanzapine, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Olanzapine

This page covers Cauliflower only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Olanzapine page lists 160 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Indian Snakeroot (major), Lithium (major), Rauvolfia Vomitoria (major) and 1,3-dmaa (moderate).

By severity: 4 major · 118 moderate · 38 minor.

From our pharmacist’s overview on the Olanzapine page

“Olanzapine (Zyprexa) is an antipsychotic prescribed for schizophrenia and bipolar disorder, and adding supplements to it warrants genuine care. Four of the 160 ingredients on file rate major, and those four deserve your attention before anything else: lithium supplements raise the risk of serotonin syndrome, activated charcoal can trap…”

Reviewed by 2 · Jul 18, 2026

Open the Olanzapine interaction page

One more smart check

Taking Cauliflower as Part of a Dietary Supplement Product? Check It for Interactions

We hold 1,705 real supplement products containing Cauliflower, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cauliflower. Your product may carry other ingredients that interact with Olanzapine too, on top of Cauliflower — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cauliflower and Olanzapine Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Cauliflower
Top 25%

#256 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Olanzapine
Top 25%

#291 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Cauliflower

What is Cauliflower?

  • General nutrition and a low-carb vegetable
  • Source of vitamin C and fiber
  • Antioxidant support
  • Digestive and gut health
  • Part of a heart-healthy diet

Cauliflower is a nutritious cruciferous vegetable that provides vitamin C, fiber, and plant compounds called glucosinolates. As a food it is healthy and safe for most people, but there is no strong proof that cauliflower supplements treat or prevent any specific disease. Enjoy it as part of a balanced diet rather than relying on pills.

Read the full Cauliflower monograph & all interactions
Medication

About Olanzapine

What Is Olanzapine Used For?

Brand name: Zyprexa

Olanzapine treats schizophrenia and the manic or mixed episodes of bipolar I disorder in both adults and adolescents (ages 13–17). It can also be used alongside valproate or lithium to treat manic or mixed episodes in adults. When combined with fluoxetine, olanzapine tablets and orally disintegrating tablets are used to treat depressive episodes associated with bipolar I disorder and treatment-resistant depression in adults.

Olanzapine intramuscular injection (short-acting) is used by healthcare providers to quickly calm acute agitation in adults with schizophrenia or bipolar I mania. Zyprexa Relprevv — a separate, long-acting intramuscular formulation available only through a restricted program — is indicated specifically for the treatment of schizophrenia in adults.

See full Olanzapine drug information
Keep checking

Other Drugs & Cauliflower

Browse every other medication we’ve checked against Cauliflower — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
185Moderate
0Minor
2,644No known interaction
185 Moderate 2,644 No interaction
Moderate

185 interactions

Showing 60 of 185 moderate interactions — see all 185 on the Cauliflower page.

No interaction 2,644 drugs checked — show the list

We also checked Cauliflower against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,644 medications checked with no known interaction — see the full Cauliflower list.

See the full Cauliflower interactions page
See every supplement checked against Olanzapine, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Cauliflower monograph › Uses, safety, and every drug interaction in one place Olanzapine supplement interactions › Every supplement checked against Olanzapine, ranked by severity Olanzapine drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cauliflower and Olanzapine Together: Common Questions

Can you take Cauliflower with Olanzapine?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Cauliflower and Olanzapine interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Olanzapine and Cauliflower?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.