Drug & supplement interaction

Cauliflower + Ethinyl estradiol, Levonogestrel

Ethinyl estradiol, Levonogestrel brand name: Lybrel.

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

Cauliflower has a moderate interaction with Ethinyl estradiol, Levonogestrel. 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 Ethinyl estradiol, Levonogestrel

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

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Ethinyl estradiol, Levonogestrel

Ethinyl estradiol, Levonogestrel 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 honest picture with cauliflower and your Lybrel pill (ethinyl estradiol with levonorgestrel). The idea on file is that cruciferous veggies like cauliflower may nudge up a liver enzyme called CYP1A2, which could speed up how fast your body clears certain medicines. In theory, that might lower the level of the hormones in your birth control a little.

But here's the reassuring part: the estrogen in your pill is mostly handled by different enzymes, not mainly CYP1A2, and the bump from cauliflower is small and based on weak, preliminary evidence. Eating cauliflower as a normal food is very unlikely to make your pill fail. If you're worried or eating large concentrated amounts, just check with your pharmacist or doctor.

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 Ethinyl estradiol, Levonogestrel 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. Ethinyl estradiol, Levonogestrel)
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.

Everything else you take

See Every Supplement That Interacts With Ethinyl estradiol, Levonogestrel

This page covers Cauliflower only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ethinyl estradiol, Levonogestrel page lists 239 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Beer (major), Grapefruit (major), Siberian Cocklebur (major) and St. John's Wort (major).

By severity: 6 major · 195 moderate · 38 minor.

From our pharmacist’s overview on the Ethinyl estradiol, Levonogestrel page

“A daily birth control pill like Lybrel (ethinyl estradiol with levonorgestrel) only works when enough hormone stays in the bloodstream, and that is exactly what several supplements on this page can undermine. This list deserves genuine care, starting with the six major-rated entries.”

Reviewed by 2 · Jul 18, 2026

Open the Ethinyl estradiol, Levonogestrel 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 Ethinyl estradiol, Levonogestrel 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 Ethinyl estradiol, Levonogestrel 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%

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

29 days ago today
Medication Ethinyl estradiol, Levonogestrel
Top 5%

#118 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
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 Ethinyl estradiol, Levonogestrel, 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 Ethinyl estradiol, Levonogestrel supplement interactions › Every supplement checked against Ethinyl estradiol, Levonogestrel, ranked by severity 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 Ethinyl estradiol, Levonogestrel Together: Common Questions

Can you take Cauliflower with Ethinyl estradiol, Levonogestrel?
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 Ethinyl estradiol, Levonogestrel 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 Ethinyl estradiol, Levonogestrel 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.