Drug & supplement interaction

Neem + Entrectinib

Entrectinib brand name: Rozlytrek.

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

Neem has a moderate interaction with Entrectinib. Theoretically, neem leaf extract might increase the levels and clinical effects of CYP3A4 substrates.

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

Neem and Entrectinib

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Entrectinib

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

Theoretically, neem leaf extract might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that neem leaf methanol extract inhibits CYP3A4 enzymes. So far, this reaction 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 Rozlytrek (entrectinib): your body relies on a liver enzyme called CYP3A4 to clear this drug out of your system. In lab studies (not yet in real people), neem leaf extract appears to slow that enzyme down. If it does the same in your body, entrectinib could build up to higher levels than intended.

That matters because more entrectinib can mean stronger side effects, things like dizziness, unsteadiness, fatigue, swelling, weight gain, or heart rhythm changes. Right now this is only a theoretical concern from test-tube data, so I don't want to alarm you. Still, with a cancer drug like this, even small shifts are worth taking seriously. Please check with your oncologist or pharmacist before using any neem product alongside it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Amaeze O, Eng H, Horlbogen L, Varma MVS, Slitt A. Cytochrome P450 Enzyme Inhibition and Herb-Drug Interaction Potential of Medicinal Plant Extracts Used for Management of Diabetes in Nigeria. Eur J Drug Metab Pharmacokinet. 2021;46(3):437-450. 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

Neem Also Interacts With Other Medications

Neem has 1,012 moderate known drug interactions in our database — the Entrectinib one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,012 No known interaction 1,818 (incl. Entrectinib)
Taking anything else?

Check Another of Your Medications Against Neem

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

Everything else you take

See Every Supplement That Interacts With Entrectinib

This page covers Neem only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Entrectinib page lists 175 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 · 127 moderate · 37 minor.

From our pharmacist’s overview on the Entrectinib page

“Grapefruit tops my worry list for anyone taking entrectinib (Rozlytrek), a targeted cancer therapy cleared by the liver enzyme CYP3A4. 121 of the 175 supplement ingredients on this page can shift how that enzyme handles the drug.”

Reviewed by 2 · Jul 18, 2026

Open the Entrectinib interaction page

One more smart check

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

We hold 288 real supplement products containing Neem, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Neem. Your product may carry other ingredients that interact with Entrectinib too, on top of Neem — 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 Neem and Entrectinib 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 Neem
Top 25%

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

29 days ago today
Medication Entrectinib
Top 10%

#202 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 Neem

What is Neem?

Neem
  • Skin conditions
  • Dental and gum health
  • Antimicrobial and antiparasitic
  • Digestive upset
  • Blood sugar support
  • Insect repellent/pesticide

Neem is a tree from India used for centuries in traditional medicine, especially for skin, dental, and antimicrobial purposes. Some small studies are promising for oral health and skin, but high-quality human evidence is limited for most uses. Neem oil and seed extracts can be toxic if swallowed, especially in children, so use with caution and talk to your pharmacist or doctor first.

Read the full Neem monograph & all interactions
Medication

About Entrectinib

What Is Entrectinib Used For?

Brand name: Rozlytrek

Rozlytrek is used to treat adult patients with ROS1-positive metastatic non-small cell lung cancer (NSCLC) — a type of lung cancer where the ROS1 gene is rearranged — as confirmed by an FDA-approved test.

Rozlytrek is also approved for adult and pediatric patients older than 1 month with solid tumors that have an NTRK gene fusion (a specific genetic alteration), detected by an FDA-approved test, that have spread or cannot be removed without causing serious harm, and have worsened after prior treatment or have no good treatment alternatives. This NTRK indication was granted accelerated approval based on tumor response rates; continued approval may depend on results from confirmatory trials.

See full Entrectinib drug information
Keep checking

Other Drugs & Neem

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

0Major
1,012Moderate
0Minor
1,817No known interaction
1,012 Moderate 1,817 No interaction
Moderate

1,012 interactions

Showing 60 of 1,012 moderate interactions — see all 1,012 on the Neem page.

No interaction 1,817 drugs checked — show the list

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

Showing the 60 most looked-up of 1,817 medications checked with no known interaction — see the full Neem list.

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

Can you take Neem with Entrectinib?
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 Neem and Entrectinib 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 Entrectinib and Neem?

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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.