Drug & supplement interaction

Bishop's Weed + Osimertinib Mesylate

Osimertinib Mesylate brand name: Tagrisso.

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

Bishop's Weed has a moderate interaction with Osimertinib Mesylate. Bergapten, a constituent of bishop's weed, has been shown to inhibit cytochrome P450 3A4 (CYP3A4) in vitro.

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

Bishop's Weed and Osimertinib Mesylate

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Osimertinib Mesylate

Osimertinib Mesylate falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Bishop's Weed interacts with.

Bergapten, a constituent of bishop's weed, has been shown to inhibit cytochrome P450 3A4 (CYP3A4) in vitro. Theoretically, bishop's weed might inhibit elimination and increase blood levels of drugs metabolized by CYP3A4.
Some drugs metabolized by CYP3A4 include alprazolam (Xanax), amitriptyline (Elavil), amiodarone (Cordarone), buspirone (Buspar), cerivastatin (Baycol), citalopram (Celexa), felodipine (Plendil), fexofenadine (Allegra), itraconazole (Sporanox), ketoconazole (Nizoral), lansoprazole (Prevacid), losartan (Cozaar), lovastatin (Mevacor), ondansetron (Zofran), prednisone (Deltasone, Orasone), sertraline (Zoloft), sibutramine (Meridia), sildenafil (Viagra), simvastatin (Zocor), verapamil (Calan, Covera-HS, Isoptin), and many 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 gist for your Tagrisso (osimertinib). Your liver uses an enzyme called CYP3A4 to help clear this cancer medication out of your body. Bishop's Weed contains a compound (bergapten) that may slow that enzyme down. If it does, osimertinib could build up higher than expected in your blood, which can mean stronger side effects like diarrhea, mouth sores, dry or rashy skin, nail changes, and tiredness.

Now, the honest part: this is mostly theoretical, based on lab studies rather than people taking these two together, so we don't know how big a real-world effect would be. Still, since osimertinib is a serious cancer drug, please don't combine them on your own. Run it by your oncologist or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Malhotra S, Bailey DG, Paine MF, Watkins PB. Seville orange juice-felodipine interaction: comparison with dilute grapefruit juice and involvement of furocoumarins. Clin Pharmacol Ther 2001;69:14-23. 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

Bishop's Weed Also Interacts With Other Medications

Bishop's Weed has 953 moderate known drug interactions in our database — the Osimertinib Mesylate one above is one of them. If you take anything else, check it against the full list below.

Moderate 953 No known interaction 1,877 (incl. Osimertinib Mesylate)
Taking anything else?

Check Another of Your Medications Against Bishop's Weed

Covers the 2,830 medications we’ve checked against Bishop's Weed. Pick one to open its full report.

From our Q&A

Questions About Bishop's Weed or Osimertinib Mesylate

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Bishop's Weed or Osimertinib Mesylate, 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 Osimertinib Mesylate

This page covers Bishop's Weed only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Osimertinib Mesylate page lists 164 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), Cesium (major) and Ephedra (major).

By severity: 8 major · 117 moderate · 39 minor.

From our pharmacist’s overview on the Osimertinib Mesylate page

“Osimertinib (Tagrisso) treats EGFR-mutated lung cancer, and this is a list to read carefully before you add anything from the supplement aisle. Of the 164 ingredients on file, most can change how much drug reaches your blood, chiefly through the CYP3A4 enzyme that clears it.”

Reviewed by 2 · Jul 18, 2026

Open the Osimertinib Mesylate interaction page

One more smart check

Taking Bishop's Weed as Part of a Dietary Supplement Product? Check It for Interactions

We hold 83 real supplement products containing Bishop's Weed, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bishop's Weed. Your product may carry other ingredients that interact with Osimertinib Mesylate too, on top of Bishop's Weed — 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 Bishop's Weed and Osimertinib Mesylate 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 Bishop's Weed
Top 25%

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

29 days ago today
Medication Osimertinib Mesylate
Steady interest

#1,814 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 Bishop's Weed

What is Bishop's Weed?

Bishop's Weed
  • Vitiligo (loss of skin color)
  • Psoriasis
  • Digestive complaints
  • Asthma and breathing problems
  • Kidney stones
  • Diuretic (increasing urine)

Bishop's Weed (Ammi majus) is a flowering plant whose seeds contain natural light-sensitizing compounds called psoralens, which have been studied mainly for skin conditions like vitiligo and psoriasis when combined with light therapy. The plant is potentially toxic and can cause severe skin and eye reactions when exposed to sunlight, so it is not something to take on your own. If you are interested in psoralen-based treatments, work with a dermatologist rather than self-treating.

Read the full Bishop's Weed monograph & all interactions
Medication

About Osimertinib

What Is Osimertinib Used For?

Brand name: Tagrisso

Tagrisso is used to treat adults with non-small cell lung cancer (NSCLC) whose tumors have specific EGFR mutations — either an exon 19 deletion or an exon 21 L858R mutation — confirmed by an FDA-approved test. It is used in several settings: after surgery to reduce the risk of cancer returning (adjuvant therapy), for locally advanced stage III NSCLC that has not progressed after chemoradiation, and as a first-line treatment for locally advanced or metastatic NSCLC (including in combination with pemetrexed and platinum-based chemotherapy).

Tagrisso is also approved for adults with metastatic NSCLC that carries a specific resistance mutation called T790M, when the cancer has stopped responding to another EGFR-targeted therapy.

See full Osimertinib drug information
Keep checking

Other Drugs & Bishop's Weed

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

0Major
953Moderate
0Minor
1,876No known interaction
953 Moderate 1,876 No interaction
Moderate

953 interactions

Showing 60 of 953 moderate interactions — see all 953 on the Bishop's Weed page.

No interaction 1,876 drugs checked — show the list

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

Showing the 60 most looked-up of 1,876 medications checked with no known interaction — see the full Bishop's Weed list.

See the full Bishop's Weed interactions page
See every supplement checked against Osimertinib Mesylate, 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
Bishop's Weed monograph › Uses, safety, and every drug interaction in one place Osimertinib Mesylate supplement interactions › Every supplement checked against Osimertinib Mesylate, ranked by severity Osimertinib 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 Bishop's Weed and Osimertinib Mesylate Together: Common Questions

Can you take Bishop's Weed with Osimertinib Mesylate?
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 Bishop's Weed and Osimertinib Mesylate 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 Osimertinib Mesylate and Bishop's Weed?

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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.