Drug & supplement interaction

Cubebs + Selpercatinib

Selpercatinib brand name: Retevmo.

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

Cubebs has a moderate interaction with Selpercatinib. Several compounds isolated from cubebs can inhibit cytochrome P450 3A4 (CYP3A4) in vitro.

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

Cubebs and Selpercatinib

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Selpercatinib

Selpercatinib falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Cubebs interacts with.

Several compounds isolated from cubebs can inhibit cytochrome P450 3A4 (CYP3A4) in vitro. So far, this effect has not been reported in humans. Theoretically, cubebs might increase the effects and side effects of drugs metabolized by CYP3A4. These include lovastatin (Mevacor), clarithromycin (Biaxin), cyclosporine (Neoral, Sandimmune), diltiazem (Cardizem), estrogens, indinavir (Crixivan), triazolam (Halcion), and numerous 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 cancer medicine Selpercatinib (Retevmo) is cleared from your body mainly by a liver enzyme called CYP3A4. Lab studies show that certain compounds in cubeb berries can slow that same enzyme down. If that happened in people, your body might break down Selpercatinib more slowly, letting it build up and possibly bringing on stronger side effects like high blood pressure, liver enzyme changes, swelling, diarrhea, or an irregular heartbeat (QT prolongation).

The reassuring part is that this is only seen in test-tube research so far, never confirmed in humans, so it's theoretical. A sprinkle of cubeb as a spice is unlikely to matter much, but concentrated cubeb extracts or oils are a different story. Since Selpercatinib is a serious medicine, please run any cubeb supplement past your oncologist or pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Usia T, Watabe T, Kadota S, Tezuka Y. Potent CYP3A4 inhibitory constituents of Piper cubeba. J Nat Prod 2005;68(1):64-8.

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

Cubebs Also Interacts With Other Medications

Cubebs has 642 moderate, 22 minor known drug interactions in our database — the Selpercatinib one above is one of them. If you take anything else, check it against the full list below.

Moderate 642 Minor 22 No known interaction 2,166 (incl. Selpercatinib)
Taking anything else?

Check Another of Your Medications Against Cubebs

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

Everything else you take

See Every Supplement That Interacts With Selpercatinib

This page covers Cubebs only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Selpercatinib page lists 178 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), Beer (major) and Cesium (major).

By severity: 11 major · 132 moderate · 35 minor.

From our pharmacist’s overview on the Selpercatinib page

“People facing a RET-driven lung or thyroid cancer often add supplements for strength, sleep, or immune support, and with selpercatinib (Retevmo) that instinct needs a careful check. Eleven of the 178 ingredients here carry a major rating, and the largest cluster affects how the drug is cleared by the CYP3A4 enzyme: St.”

Reviewed by 2 · Jul 18, 2026

Open the Selpercatinib interaction page

One more smart check

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

We hold 19 real supplement products containing Cubebs, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cubebs. Your product may carry other ingredients that interact with Selpercatinib too, on top of Cubebs — 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 Cubebs and Selpercatinib 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 Cubebs
Top half

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

29 days ago today
Medication Selpercatinib
Top 10%

#153 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 Cubebs

What is Cubebs?

Cubebs
  • Coughs and bronchitis
  • Indigestion and gas
  • Urinary tract complaints
  • Sore throat
  • Culinary spice

Cubebs are spicy, peppery berries from a vine in the pepper family that have long been used in traditional medicine for coughs, digestion, and urinary problems. Modern human studies are very limited, so its benefits are not well proven. Use it cautiously as a food spice, and talk to your pharmacist or doctor before using concentrated extracts or oils.

Read the full Cubebs monograph & all interactions
Medication

About Selpercatinib

What Is Selpercatinib Used For?

Brand name: Retevmo

Selpercatinib treats cancers driven by changes in the RET gene — either a gene fusion (where RET joins abnormally with another gene) or a RET mutation (a change in the gene itself). Your doctor will confirm one of these changes with an FDA-approved test before prescribing it.

It is approved for adults with RET fusion-positive non-small cell lung cancer; adults and children 2 and older with RET-mutant medullary thyroid cancer or RET fusion-positive thyroid cancer; and adults and children 2 and older with other advanced solid tumors that have a RET gene fusion and have not responded to prior treatment.

See full Selpercatinib drug information
Keep checking

Other Drugs & Cubebs

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

0Major
642Moderate
22Minor
2,165No known interaction
642 Moderate 22 Minor 2,165 No interaction
Moderate

642 interactions

Showing 60 of 642 moderate interactions — see all 642 on the Cubebs page.

Minor

22 interactions

No interaction 2,165 drugs checked — show the list

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

Showing the 60 most looked-up of 2,165 medications checked with no known interaction — see the full Cubebs list.

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

Can you take Cubebs with Selpercatinib?
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 Cubebs and Selpercatinib 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 Selpercatinib and Cubebs?

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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.