Drug & supplement interaction

Cannabis + Imatinib

Imatinib brand name: Gleevec.

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

Imatinib falls into 3 drug categories that Cannabis can interact with; the most serious is rated moderate. Theoretically, drugs that are CYP2C9 inhibitors might increase the adverse effects of cannabis.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Cannabis and Imatinib

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

Why Are There 3 Interactions?

Cannabis interacts with whole categories of medication. Imatinib falls into 3 of those categories, so it can interact with Cannabis 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 2C9 (CYP2C9) INHIBITORS

1 of 3

Why this applies to Imatinib

Imatinib falls under CYTOCHROME P450 2C9 (CYP2C9) INHIBITORS — the group Cannabis interacts with.

Theoretically, drugs that are CYP2C9 inhibitors might increase the adverse effects of cannabis.
Delta-9-tetrahydrocannabinol (THC), an active constituent of cannabis, is a substrate of CYP2C9 enzymes.
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 key thing to understand: in this pairing, it's the cannabis that may be affected, not your imatinib (Gleevec). THC, the part of cannabis that gets you high, is partly broken down by a liver enzyme called CYP2C9. Imatinib can slow that enzyme down. So in theory, the THC could hang around longer and hit harder, meaning more intense effects like dizziness, drowsiness, a faster heartbeat, confusion, or stronger impairment.

I want to be honest about the strength here: this is a theoretical concern based on how these compounds behave, not something proven in real patients. Still, since both can stress the liver and cause tiredness, it's worth a quick chat with your oncologist or pharmacist before mixing them. Please don't change anything on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS

2 of 3

Imatinib also falls under CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS.

Theoretically, CYP3A4 inhibitors might increase the levels and adverse effects of cannabis.
Delta-9-tetrahydrocannabinol (THC), an active constituent of cannabis, is a substrate of CYP3A4 enzymes.
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 something worth knowing if you use cannabis while on imatinib (Gleevec). Imatinib gently blocks an enzyme in your liver called CYP3A4, which is one of the main pathways that breaks down THC, the part of cannabis that gets you high. By slowing that cleanup, imatinib could let THC build up a bit more than usual, meaning the cannabis itself might hit harder and last longer than you expect.

In plain terms, you might feel more drowsy, dizzy, foggy, or have a faster heartbeat from the cannabis, not from the imatinib. This is theoretical, based on how the drugs work on paper rather than strong real-world studies, so it may be mild or unnoticeable. Still, please loop in your doctor or pharmacist before combining them, especially since your cancer treatment matters most here.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

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

Theoretically, cannabis may increase the levels and adverse effects of CYP3A4 substrates.
In vitro research shows that cannabis can inhibit the activity of CYP3A4 enzymes, which might decrease the metabolism of CYP3A4 substrates. In vitro research also shows that cannabis extracts modestly inhibit the CYP3A4 metabolism of testosterone; extracts providing the specific cannabinoids CBD and cannabigerol (CBG) had stronger inhibitory effects than extracts containing THC and CBD.
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 with Gleevec (imatinib) and cannabis. Your liver uses an enzyme called CYP3A4 to break imatinib down. Lab studies suggest cannabis, especially CBD-heavy products, can slow that enzyme a bit. If that happens in your body, imatinib could clear more slowly and build up, which may mean more of its usual side effects like nausea, fluid retention and puffiness around the eyes, muscle cramps, fatigue, or low blood counts.

I want to be honest, though: this is theoretical, based only on test-tube research, not real patient cases, so we don't know how big a deal it actually is. Imatinib matters too much to guess with, so please loop in your oncology team or pharmacist before mixing in cannabis.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pellinen, P., Honkakoski, P., Stenback, F., Niemitz, M., Alhava, E., Pelkonen, O., Lang, M. A., and Pasanen, M. Cocaine N-demethylation and the metabolism-related hepatotoxicity can be prevented by cytochrome P450 3A inhibitors. Eur.J Pharmacol 1-3-1994;2 PubMed
  2. Treyer A, Reinhardt JK, Eigenmann DE, Oufir M, Hamburger M. Phytochemical comparison of medicinal cannabis extracts and study of their CYP-mediated interactions with coumarinic oral anticoagulants. Med Cannabis Cannabinoids. 2023;6(1):21-31. 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

Cannabis Also Interacts With Other Medications

Cannabis has 2 major, 1,108 moderate, 25 minor known drug interactions in our database — the Imatinib one above is among them. If you take anything else, check it against the full list below.

Major 2 Moderate 1,108 Minor 25 No known interaction 1,695 (incl. Imatinib)
Taking anything else?

Check Another of Your Medications Against Cannabis

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

From our Q&A

Questions About Cannabis or Imatinib

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cannabis or Imatinib, 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 Imatinib

This page covers Cannabis only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Imatinib page lists 153 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 · 106 moderate · 39 minor.

From our pharmacist’s overview on the Imatinib page

“Imatinib (Gleevec) treats certain leukemias and gastrointestinal tumors, and because keeping its blood level steady is what keeps the cancer controlled, this list deserves genuine attention before you add anything to it. Most of the interactions trace back to how the body clears imatinib through an enzyme called CYP3A4.”

Reviewed by 2 · Jul 18, 2026

Open the Imatinib interaction page

One more smart check

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

We hold 21 real supplement products containing Cannabis, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cannabis. Your product may carry other ingredients that interact with Imatinib too, on top of Cannabis — 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 Cannabis and Imatinib 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 Cannabis
Top 25%

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

29 days ago today
Medication Imatinib
Steady interest

#1,842 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 Cannabis

What is Cannabis?

Cannabis
  • Chronic pain
  • Nausea and vomiting from chemotherapy
  • Muscle spasticity (e.g., multiple sclerosis)
  • Anxiety and stress
  • Sleep problems
  • Appetite stimulation

Cannabis contains many active compounds, mainly THC (which causes a 'high') and CBD (which does not). Some uses, such as chemotherapy-related nausea, certain seizure disorders, and muscle spasticity, have meaningful evidence, while many other popular uses are not well proven. It can cause real side effects and impairment, so talk to your doctor or pharmacist and follow your local laws before using it.

Read the full Cannabis monograph & all interactions
Medication

About Imatinib

What Is Imatinib Used For?

Brand name: Gleevec

Imatinib treats a range of blood cancers and solid tumors. It is used for Philadelphia chromosome positive chronic myeloid leukemia (Ph+ CML) in adults and children — whether newly diagnosed or in more advanced phases — and for Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL) in both adults and pediatric patients.

It is also used for Kit-positive gastrointestinal stromal tumors (GIST), including after surgical removal, and for several rarer conditions: myelodysplastic/myeloproliferative diseases (MDS/MPD) linked to specific gene changes, aggressive systemic mastocytosis (ASM), hypereosinophilic syndrome (HES) and/or chronic eosinophilic leukemia (CEL), and unresectable, recurrent, or metastatic dermatofibrosarcoma protuberans (DFSP).

See full Imatinib drug information
Keep checking

Other Drugs & Cannabis

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

2Major
1,108Moderate
25Minor
1,694No known interaction
2 Major 1,108 Moderate 25 Minor 1,694 No interaction
Major

2 interactions

Moderate

1,108 interactions

Showing 60 of 1,108 moderate interactions — see all 1,108 on the Cannabis page.

Minor

25 interactions

No interaction 1,694 drugs checked — show the list

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

Showing the 60 most looked-up of 1,694 medications checked with no known interaction — see the full Cannabis list.

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

Can you take Cannabis with Imatinib?
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 Cannabis and Imatinib?
Imatinib belongs to more than one drug category, and Cannabis 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 Cannabis and Imatinib 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 Imatinib and Cannabis?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.