Drug & supplement interaction

Methoxylated Flavones + Etoposide

Etoposide brand names: VePesid, VP16, Etopophos.

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

Etoposide falls into 3 drug categories that Methoxylated Flavones can interact with; the most serious is rated moderate. In vitro evidence shows that some methoxylated flavones including tangeretin, nobiletin, and heptamethoxyflavone, inhibit P-glycoprotein.

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

Methoxylated Flavones and Etoposide

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. Etoposide 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

P-GLYCOPROTEIN SUBSTRATES

1 of 3

Why this applies to Etoposide

Etoposide falls under P-GLYCOPROTEIN SUBSTRATES — the group Methoxylated Flavones interacts with.

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 etoposide: your body uses a kind of cellular bouncer called P-glycoprotein to push this chemo drug out of cells and help clear it. In lab dish studies, certain methoxylated flavones (like nobiletin and tangeretin from citrus peel) can block that bouncer. In theory, that could let more etoposide stay in your system, nudging blood levels up.

With a chemo drug, higher levels could mean more of the usual side effects, things like low blood counts, infection risk, mouth sores, nausea, or fatigue. That said, this is theoretical and based only on lab work, not real patients, so I don't want to alarm you. Still, since you're on cancer treatment, please run any citrus-peel supplements past your oncology team or pharmacist 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

2 of 3

Etoposide 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 for etoposide (VP16): your body relies on a liver enzyme called CYP3A4 to help clear this chemo drug. In test-tube studies, certain methoxylated flavones from citrus peel can slow that same enzyme down. If that happened in real life, etoposide could build up a bit higher than expected, which might mean more of its typical side effects, like low blood counts, mouth sores, nausea, or a higher infection risk.

The honest caveat: this is only lab data, it doesn't happen with every flavone, and it hasn't been seen in actual patients. Still, since etoposide is serious cancer treatment, please loop in your oncology team or pharmacist before adding any concentrated supplement.

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
Moderate

ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP)

3 of 3

Etoposide also falls under ORGANIC ANION-TRANSPORTING POLYPEPTIDE SUBSTRATES (OATP).

In vitro, methoxylated flavones inhibit organic anion transporting polypeptide (OATP) 1B1, 1B3, and 2B1. This may reduce the bioavailability of oral drugs that are substrates of OATP. However, this interaction has not been reported in humans.
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 etoposide. Certain citrus peel compounds called methoxylated flavones have been shown, in test tube studies, to block transporters known as OATP that help carry some medicines into your cells and bloodstream. Etoposide relies in part on these transporters, so the concern is that big supplement doses could lower how much active drug your body actually takes up.

If that happened, your etoposide might work a little less well against the cancer, which obviously matters with chemotherapy. But I want to be honest: this is only seen in lab dishes, never confirmed in people, so it stays theoretical for now. A bit of citrus in your diet is very unlikely to be an issue. Before adding any concentrated flavone supplement, please run it by your oncology team or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Bajraktari-Sylejmani G, Weiss J. Potential risk of food-drug interactions: Citrus polymethoxyflavones and flavanones as inhibitors of the organic anion transporting polypeptides (OATP) 1B1, 1B3, and 2B1. Eur J Drug Metab Pharmacokinet. 2020;45(6):809-815. 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 Etoposide 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. Etoposide)
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 Etoposide

This page covers Methoxylated Flavones only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Etoposide page lists 152 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Grapefruit (major), St. John's Wort (major) and Sweet Orange (major).

By severity: 5 major · 107 moderate · 40 minor.

From our pharmacist’s overview on the Etoposide page

“Chemotherapy is unforgiving of level swings, and swings are exactly what most of this list can cause for etoposide (VePesid, Etopophos). Of the 152 supplements and herbs on file, 121 can change how your liver clears etoposide through the CYP3A4 enzyme, meaning too little drug and an undertreated cancer, or too much and harsher toxicity.”

Reviewed by 2 · Jul 18, 2026

Open the Etoposide interaction page

How much people look this up

Where Methoxylated Flavones and Etoposide 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
Steady interest

#1,175 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Etoposide
Steady interest

#1,496 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
Medication

About Etoposide

What Is Etoposide Used For?

Brand names: VePesid, VP16, Etopophos

Etoposide injection (available as Avopef, Etopophos, Toposar, and Etoposide) is used to treat refractory testicular tumors — cancers that have already been treated with surgery, radiation, and other chemotherapy — always in combination with other cancer drugs. It is also used for small cell lung cancer (SCLC) as a first-line treatment, given together with other chemotherapy and, in the case of Avopef, with immunotherapy as well.

Etoposide capsules (VePesid and Etoposide capsules) are approved for small cell lung cancer as first-line treatment in combination with other chemotherapy agents. Capsule forms are not approved for testicular cancer, as the label notes that adequate data on their use in that setting are not available.

See full Etoposide drug information
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 Etoposide, 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 Etoposide supplement interactions › Every supplement checked against Etoposide, ranked by severity Etoposide 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 Methoxylated Flavones and Etoposide Together: Common Questions

Can you take Methoxylated Flavones with Etoposide?
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 Etoposide?
Etoposide 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 Etoposide 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 Etoposide and Methoxylated Flavones?

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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.