Drug & supplement interaction

Rosemary + Flutamide

Flutamide brand names: Eulexin, Euflex.

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

Rosemary has a minor interaction with Flutamide. Theoretically, rosemary might decrease the levels and clinical effects of CYP1A2 substrates.

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

Rosemary and Flutamide

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

Minor

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Why this applies to Flutamide

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

Theoretically, rosemary might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that rosemary induces CYP1A2 enzymes. This effect has not been reported in humans.
Severity Minor Likelihood Unlikely Evidence D

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

Here's the gist for your prostate cancer treatment. Your liver uses an enzyme called CYP1A2 to process flutamide. Lab and animal studies hint that rosemary might speed up that enzyme, which in theory could clear flutamide a bit faster and leave slightly less of it working in your body. Since flutamide helps block testosterone from feeding cancer cells, the worry would be a small drop in how well it works.

I want to be honest, though: this has only been seen in test tubes and animals, never in real people, so it's flagged as minor and unlikely. Cooking with rosemary or enjoying it in food is no concern. If you're thinking about concentrated rosemary capsules or oil, just run it by your oncology team or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Debersac P, Heydel JM, Amiot MJ, et al. Induction of cytochrome P450 and/or detoxication enzymes by various extracts of rosemary: description of specific patterns. Food Chem Toxicol 2001;39(9):907-18. PubMed
  2. Debersac P, Vernevaut MF, Amiot MJ, et al. Effects of a water-soluble extract of rosemary and its purified component rosmarinic acid on xenobiotic-metabolizing enzymes in rat liver. Food Chem Toxicol 2001;39(2):109-17. 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

Rosemary Also Interacts With Other Medications

Rosemary has 212 moderate, 159 minor known drug interactions in our database — the Flutamide one above is one of them. If you take anything else, check it against the full list below.

Moderate 212 Minor 159 No known interaction 2,459 (incl. Flutamide)
Taking anything else?

Check Another of Your Medications Against Rosemary

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

Everything else you take

See Every Supplement That Interacts With Flutamide

This page covers Rosemary only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Flutamide page lists 189 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 143 moderate · 43 minor.

From our pharmacist’s overview on the Flutamide page

“A man taking flutamide (Eulexin) to block testosterone during prostate cancer treatment cannot afford big swings in the drug's level, and most of the 189 supplements on this page are capable of causing exactly that. The bulk of them work through the liver enzyme CYP3A4, which breaks flutamide down.”

Reviewed by 2 · Jul 18, 2026

Open the Flutamide interaction page

One more smart check

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

We hold 1,786 real supplement products containing Rosemary, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Rosemary. Your product may carry other ingredients that interact with Flutamide too, on top of Rosemary — 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 Rosemary and Flutamide 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 Rosemary
Top 25%

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

29 days ago today
Medication Flutamide
Top 10%

#193 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 Rosemary

What is Rosemary?

Rosemary
  • Memory and concentration
  • Digestive upset
  • Hair growth
  • Anxiety and stress (aromatherapy)
  • Muscle and joint discomfort
  • Antioxidant support

Rosemary is a fragrant Mediterranean herb that is safe and flavorful in normal food amounts. Some early research suggests possible benefits for memory, mood, and hair growth, but the evidence is limited and far from conclusive. Concentrated supplements and the essential oil should be used carefully, and the essential oil should never be swallowed.

Read the full Rosemary monograph & all interactions
Medication

About Flutamide

What Is Flutamide Used For?

Brand names: Eulexin, Euflex

Eulexin (flutamide) capsules are used to treat prostate cancer in men. They are always used together with an LHRH agonist (a hormone-lowering injection), never alone.

Eulexin is indicated for two stages of prostate cancer: locally confined Stage B2-C prostate cancer (used alongside goserelin acetate and radiation therapy, starting eight weeks before radiation begins) and Stage D2 metastatic prostate cancer (cancer that has spread beyond the prostate, taken with an LHRH agonist until the disease progresses).

See full Flutamide drug information
Keep checking

Other Drugs & Rosemary

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

0Major
212Moderate
159Minor
2,458No known interaction
212 Moderate 159 Minor 2,458 No interaction
Moderate

212 interactions

Showing 60 of 212 moderate interactions — see all 212 on the Rosemary page.

Minor

159 interactions

Showing 60 of 159 minor interactions — see all 159 on the Rosemary page.

No interaction 2,458 drugs checked — show the list

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

Showing the 60 most looked-up of 2,458 medications checked with no known interaction — see the full Rosemary list.

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

Can you take Rosemary with Flutamide?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Rosemary and Flutamide interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Flutamide and Rosemary?

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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.