Drug & supplement interaction

Cabbage + Clozapine

Clozapine brand names: Clozaril, Versacloz.

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

Cabbage has a moderate interaction with Clozapine. Theoretically, cabbage might decrease levels of drugs metabolized by CYP1A2.

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

Cabbage and Clozapine

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

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Clozapine

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

Theoretically, cabbage might decrease levels of drugs metabolized by CYP1A2.
Some animal research suggests that cabbage or its constituent indole-3-carbinol might increase drug metabolism and elimination by stimulating CYP1A2 activity.
Severity Moderate Likelihood Possible Evidence D

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 for clozapine: your body relies on a liver enzyme called CYP1A2 to clear it from your system. Lab and animal studies hint that compounds in cabbage (especially indole-3-carbinol) might rev up that enzyme a bit. If that happened in people, your body could break clozapine down faster, which may lower your blood levels and let symptoms creep back. Clozapine is a touchy drug where steady levels really matter, so even modest shifts deserve attention.

The reassuring part: this is only theoretical, based on lab and animal work, not human studies. Normal amounts of cabbage on your plate are very unlikely to cause trouble. I'd just avoid suddenly loading up on cabbage supplements or huge amounts, and loop in your doctor or pharmacist if you do.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Balk JL. Indole-3-carbinol for cancer prevention. Altern Med Alert 2000; 3:105-7.
  2. He YH, Friesen MD, Ruch RJ, Schut HA. Indole-3-carbinol as a chemopreventive agent in 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) carcinogenesis: inhibition of PhIP-DNA adduct formation, acceleration of PhIP metabolism, and induction of cytoch
  3. Steinkellner, H., Rabot, S., Freywald, C., Nobis, E., Scharf, G., Chabicovsky, M., Knasmuller, S., and Kassie, F. Effects of cruciferous vegetables and their constituents on drug metabolizing enzymes involved in the bioactivation of DNA-reactive dietary c

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

Cabbage Also Interacts With Other Medications

Cabbage has 324 moderate known drug interactions in our database — the Clozapine one above is one of them. If you take anything else, check it against the full list below.

Moderate 324 No known interaction 2,506 (incl. Clozapine)
Taking anything else?

Check Another of Your Medications Against Cabbage

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

From our Q&A

Questions About Cabbage or Clozapine

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cabbage or Clozapine, 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 Clozapine

This page covers Cabbage only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Clozapine page lists 212 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Henbane (major), Indian Snakeroot (major), Lithium (major) and Rauvolfia Vomitoria (major).

By severity: 6 major · 164 moderate · 42 minor.

From our pharmacist’s overview on the Clozapine page

“Clozapine (Clozaril, Versacloz) is usually the last-resort antipsychotic for schizophrenia, prescribed under close monitoring because small shifts in its blood level matter, so the 212 supplement interactions on file here deserve genuine care rather than a quick skim. Six are rated major.”

Reviewed by 2 · Jul 18, 2026

Open the Clozapine interaction page

One more smart check

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

We hold 2,304 real supplement products containing Cabbage, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cabbage. Your product may carry other ingredients that interact with Clozapine too, on top of Cabbage — 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 Cabbage and Clozapine 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 Cabbage
Top 25%

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

29 days ago today
Medication Clozapine
Steady interest

#1,564 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 Cabbage

What is Cabbage?

Cabbage
  • Breast engorgement during breastfeeding
  • Joint pain and swelling (topical)
  • Digestive and stomach upset
  • General nutrition and antioxidant support
  • Skin and minor inflammation (topical)

Cabbage is a nutritious, low-calorie vegetable that is safe to eat as food and is sometimes applied to the skin as a leaf wrap for breast engorgement or sore joints. Most medicinal claims are based on tradition or limited research, with the strongest (though still modest) evidence being for cooling cabbage leaves on engorged breasts. Talk to your pharmacist or doctor before using cabbage in large amounts or as a treatment.

Read the full Cabbage monograph & all interactions
Medication

About Clozapine

What Is Clozapine Used For?

Brand names: Clozaril, Versacloz

Clozapine is used for two specific situations. First, it is prescribed for people with severe schizophrenia who have already tried other antipsychotic medications and have not gotten adequate relief. It is reserved for this group because of its serious risks.

Second, clozapine is used to lower the chances of repeated suicidal behavior in people with schizophrenia or schizoaffective disorder who are considered to be at ongoing, chronic risk. It is not a first-choice medication — it is used when the need is serious and other options have fallen short.

See full Clozapine drug information
Keep checking

Other Drugs & Cabbage

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

0Major
324Moderate
0Minor
2,505No known interaction
324 Moderate 2,505 No interaction
Moderate

324 interactions

Showing 60 of 324 moderate interactions — see all 324 on the Cabbage page.

No interaction 2,505 drugs checked — show the list

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

Showing the 60 most looked-up of 2,505 medications checked with no known interaction — see the full Cabbage list.

See the full Cabbage interactions page
See every supplement checked against Clozapine, 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
Cabbage monograph › Uses, safety, and every drug interaction in one place Clozapine supplement interactions › Every supplement checked against Clozapine, ranked by severity Clozapine 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 Cabbage and Clozapine Together: Common Questions

Can you take Cabbage with Clozapine?
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 Cabbage and Clozapine 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 Clozapine and Cabbage?

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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.