Drug & supplement interaction

Methoxylated Flavones + Estradiol

Estradiol brand names: Estrace, Gynodiol, Vagifem, Estring, Vivelle, and others.

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

Estradiol falls into 3 drug categories that Methoxylated Flavones can interact with; the most serious is rated moderate. Some in vitro evidence suggests that methoxylated flavones might induce CYP1A2, possibly by increasing gene transcription.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Methoxylated Flavones and Estradiol

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Methoxylated Flavones interacts with whole categories of medication. Estradiol falls into 3 of those categories, so it can interact with Methoxylated Flavones in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

1 of 3

Why this applies to Estradiol

Estradiol falls under CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES — the group Methoxylated Flavones interacts with.

Some in vitro evidence suggests that methoxylated flavones might induce CYP1A2, possibly by increasing gene transcription. However, other in vitro research has not shown this effect. So far this interaction has not been reported in humans. Theoretically, concurrent use of methoxylated flavones and drugs metabolized by CYP1A2 might increase drug metabolism, decrease serum levels, and reduce effectiveness.
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 (Slo-bid, Theo-Dur, others), zileuton (Zyflo), Zolmitriptan (Zomig), and others.
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 basic idea: your body uses an enzyme called CYP1A2 to help break down estradiol. Lab studies hint that methoxylated flavones (the compounds found in citrus peel) might speed up that enzyme. If that happened, your estradiol could clear out a little faster, which in theory might make it work less well. For vaginal estradiol, that could mean less relief from dryness, burning, itching, or hot flashes.

I want to be honest with you though: this is only a theoretical concern from test-tube research, and some lab studies didn't even show the effect. It has never been reported in real people, and ordinary citrus in food is very unlikely to matter. Concentrated supplements are the bigger question mark. If you're considering one, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Middleton E, Kandaswami C, Theoharides TC. The effects of plant flavonoids on mammalian cells: implications for inflammation, heart disease, and cancer. Pharmacol Rev 2000;52:673-751. DOI
  2. Li Y, Ning J, Wang Y, et al. Drug interaction study of flavonoids toward CYP3A4 and their quantitative structure activity relationship (QSAR) analysis for predicting potential effects. Toxicol Lett. 2018 Sep 15;294:27-36. PubMed
Moderate

P-GLYCOPROTEIN SUBSTRATES

2 of 3

Estradiol also falls under P-GLYCOPROTEIN SUBSTRATES.

In vitro evidence shows that some methoxylated flavones including tangeretin, nobiletin, and heptamethoxyflavone, inhibit P-glycoprotein. Theoretically, these methoxylated flavones might increase absorption and blood levels of drugs that are transported by P-glycoprotein.
Some of these drugs include some chemotherapeutic agents (daunorubicin, docetaxel, etoposide, paclitaxel, vinblastine, vincristine, vindesine), antifungals (ketoconazole, itraconazole), protease inhibitors (amprenavir, indinavir, nelfinavir, saquinavir), H2 antagonists (cimetidine, ranitidine), some calcium channel blockers (diltiazem, verapamil), corticosteroids, erythromycin, cisapride (Propulsid), fexofenadine (Allegra), cyclosporine, loperamide (Imodium), quinidine, and others.
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 estradiol. Some of these citrus-peel flavones (like nobiletin and tangeretin) can block a transporter pump called P-glycoprotein. Estradiol is moved around by that pump, so in theory, slowing it down could let a little more estradiol get absorbed and raise your levels slightly. If that happened, you might notice more of the usual estrogen-type effects, things like breast tenderness, bloating, headache, nausea, or spotting.

The big caveat: this is based only on lab dish studies, not real people, so it's very theoretical. The tiny amounts of these flavones you'd get from food are unlikely to matter. Concentrated supplements are a bigger question mark. If you're considering one, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Takanaga H, Ohnishi A, Yamada S, et al. Polymethoxylated flavones in orange juice are inhibitors of P-glycoprotein but not cytochrome P450 3A4. J Pharmacol Exp Ther 2000;293:230-6. DOI
  2. Feng SL, Yuan ZW, Yao XJ, et al. Tangeretin, a citrus pentamethoxyflavone, antagonizes ABCB1-mediated multidrug resistance by inhibiting its transport function. Pharmacol Res 2016;110:193-204. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Estradiol also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

In vitro evidence suggests that methoxylated flavones might inhibit cytochrome P450 3A4 (CYP3A4). This effect seems to be structure-dependent, and does not occur with all methoxylated flavones. So far this interaction has not been reported in humans. Theoretically, concurrent use of certain methoxylated flavones with drugs metabolized by CYP3A4 might result in increased drug levels and an increased risk for adverse effects.
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 (Slo-bid, Theo-Dur, others), zileuton (Zyflo), Zolmitriptan (Zomig), and others.
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: your body uses an enzyme called CYP3A4 to break down estradiol. Certain methoxylated flavones from citrus peel (think nobiletin and tangeretin) may slow that enzyme down in test-tube studies. If that happened in real life, your estradiol could clear a little slower and build up, possibly nudging up estrogen-related effects like breast tenderness, bloating, headaches, or spotting.

The good news is this is theoretical so far. It comes from lab and animal work only and hasn't been seen in people, and not all of these flavones even cause it. Eating an orange won't do this, but concentrated supplements are a bigger unknown. If you want to take one alongside estradiol, just run it by your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Li Y, Ning J, Wang Y, et al. Drug interaction study of flavonoids toward CYP3A4 and their quantitative structure activity relationship (QSAR) analysis for predicting potential effects. Toxicol Lett. 2018 Sep 15;294:27-36. 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

Methoxylated Flavones Also Interacts With Other Medications

Methoxylated Flavones has 891 moderate known drug interactions in our database — the Estradiol one above is among them. If you take anything else, check it against the full list below.

Moderate 891 No known interaction 1,939 (incl. Estradiol)
Taking anything else?

Check Another of Your Medications Against Methoxylated Flavones

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

Everything else you take

See Every Supplement That Interacts With Estradiol

This page covers Methoxylated Flavones only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Estradiol page lists 213 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 · 172 moderate · 38 minor.

From our pharmacist’s overview on the Estradiol page

“Estradiol (Estrace, Vivelle, Vagifem, and other brands) is estrogen therapy, and its interaction list deserves careful reading, especially the three entries rated major. Grapefruit can push estradiol levels higher, St.”

Reviewed by 2 · Jul 18, 2026

Open the Estradiol interaction page

How much people look this up

Where Methoxylated Flavones and Estradiol 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 Methoxylated Flavones
Top half

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

29 days ago today
Medication Estradiol
Top 25%

#355 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 Methoxylated Flavones

What is Methoxylated Flavones?

  • Antioxidant support
  • Circulation and blood vessel health
  • Anti-inflammatory support
  • Skin and aging support
  • General 'metabolism' or wellness blends

Methoxylated flavones (often called polymethoxyflavones) are a group of plant compounds, found mainly in citrus peel, that include substances like nobiletin and tangeretin. Lab and animal studies suggest possible antioxidant and anti-inflammatory effects, but solid human research is very limited, so their real-world benefits are unproven. Talk with a pharmacist or doctor before using them, especially if you take medicines or are pregnant or breastfeeding.

Read the full Methoxylated Flavones monograph & all interactions
Keep checking

Other Drugs & Methoxylated Flavones

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

0Major
891Moderate
0Minor
1,938No known interaction
891 Moderate 1,938 No interaction
Moderate

891 interactions

Showing 60 of 891 moderate interactions — see all 891 on the Methoxylated Flavones page.

No interaction 1,938 drugs checked — show the list

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

Showing the 60 most looked-up of 1,938 medications checked with no known interaction — see the full Methoxylated Flavones list.

See the full Methoxylated Flavones interactions page
See every supplement checked against Estradiol, 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
Methoxylated Flavones monograph › Uses, safety, and every drug interaction in one place Estradiol supplement interactions › Every supplement checked against Estradiol, 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 Methoxylated Flavones and Estradiol Together: Common Questions

Can you take Methoxylated Flavones with Estradiol?
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.
Why are there 3 interactions listed for Methoxylated Flavones and Estradiol?
Estradiol belongs to more than one drug category, and Methoxylated Flavones interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Methoxylated Flavones and Estradiol 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

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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.