Drug & supplement interaction

Brussels Sprout + Tamoxifen Citrate

Tamoxifen Citrate brand names: Nolvadex, Soltamox.

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

Brussels Sprout has a moderate interaction with Tamoxifen Citrate. A cabbage and Brussels sprout-containing diet seems to boost elimination through glucuronide conjugation.

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

Brussels Sprout and Tamoxifen Citrate

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

Moderate

GLUCURONIDATED DRUGS

Why this applies to Tamoxifen Citrate

Tamoxifen Citrate falls under GLUCURONIDATED DRUGS — the group Brussels Sprout interacts with.

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.
Severity Moderate Likelihood Probable Evidence B

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..

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

Here's the gist for tamoxifen. Some research suggests that a diet rich in cabbage and Brussels sprouts can speed up a clearing process in the body called glucuronidation. In theory, that could nudge your body to remove certain medications a bit faster. The catch with tamoxifen is that it works partly by being converted into a stronger active form (endoxifen), so anything that lowers its levels could, in theory, make it work less well at protecting against or treating breast cancer.

That said, this concern is mostly theoretical, and normal food amounts of Brussels sprouts on your dinner plate are very unlikely to throw off your treatment. Keep enjoying them as part of a healthy diet. Before using concentrated cruciferous vegetable supplements, though, please check with your oncologist or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pantuck EJ, Pantuck CB, Anderson KE, et al. Effect of brussels sprouts and cabbage on drug conjugation. Clin Pharmacol Ther 1984;35:161-9. PubMed

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

Brussels Sprout Also Interacts With Other Medications

Brussels Sprout has 240 moderate known drug interactions in our database — the Tamoxifen Citrate one above is one of them. If you take anything else, check it against the full list below.

Moderate 240 No known interaction 2,590 (incl. Tamoxifen Citrate)
Taking anything else?

Check Another of Your Medications Against Brussels Sprout

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

From our Q&A

Questions About Brussels Sprout or Tamoxifen Citrate

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

This page covers Brussels Sprout only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tamoxifen Citrate page lists 210 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 166 moderate · 33 minor.

From our pharmacist’s overview on the Tamoxifen Citrate page

“Tamoxifen (Nolvadex, Soltamox) often stands between a breast cancer patient and a recurrence, so the stakes on this page run higher than usual. Eleven of the 210 supplements and herbs on file carry a major rating, and those eleven deserve your attention ahead of everything else.”

Reviewed by 2 · Jul 18, 2026

Open the Tamoxifen Citrate interaction page

How much people look this up

Where Brussels Sprout and Tamoxifen Citrate 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 Brussels Sprout
Steady interest

#1,210 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Tamoxifen Citrate
Top 25%

#399 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 Brussels Sprout

What is Brussels Sprout?

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

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.

Read the full Brussels Sprout monograph & all interactions
Medication

About Tamoxifen

What Is Tamoxifen Used For?

Brand names: Nolvadex, Soltamox

Tamoxifen is used to treat estrogen receptor-positive metastatic breast cancer in both women and men, and as follow-up (adjuvant) therapy after surgery for early-stage breast cancer in women. It also reduces the occurrence of cancer in the opposite breast when used as adjuvant therapy.

In women with ductal carcinoma in situ (DCIS — an early, non-invasive breast change) following surgery and radiation, tamoxifen lowers the risk of developing invasive breast cancer. It is also approved to reduce the risk of breast cancer in women who are at high risk but have not yet been diagnosed. Both Tamoxifen Citrate tablets and Soltamox oral solution share these indications.

See full Tamoxifen drug information
Keep checking

Other Drugs & Brussels Sprout

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

0Major
240Moderate
0Minor
2,589No known interaction
240 Moderate 2,589 No interaction
Moderate

240 interactions

Showing 60 of 240 moderate interactions — see all 240 on the Brussels Sprout page.

No interaction 2,589 drugs checked — show the list

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

Showing the 60 most looked-up of 2,589 medications checked with no known interaction — see the full Brussels Sprout list.

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

Can you take Brussels Sprout with Tamoxifen Citrate?
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 Brussels Sprout and Tamoxifen Citrate 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 Tamoxifen Citrate and Brussels Sprout?

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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.