Drug & supplement interaction

Cannabidiol (cbd) + Donepezil

Donepezil brand name: Aricept.

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

Donepezil falls into 2 drug categories that Cannabidiol (cbd) can interact with; the most serious is rated moderate. Theoretically, cannabidiol might increase levels of drugs metabolized by CYP2D6.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cannabidiol (cbd) and Donepezil

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Cannabidiol (cbd) interacts with whole categories of medication. Donepezil falls into 2 of those categories, so it can interact with Cannabidiol (cbd) in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

1 of 2

Why this applies to Donepezil

Donepezil falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES — the group Cannabidiol (cbd) interacts with.

Theoretically, cannabidiol might increase levels of drugs metabolized by CYP2D6.
In vitro research shows that cannabidiol inhibits CYP2D6. Theoretically, concomitant use of cannabidiol with CYP2D6 substrates might increase the risk for adverse effects from these substrates. However, a clinical crossover trial in healthy adults shows that cannabidiol does not inhibit dextromethorphan, a substrate of CYP2D6.
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 situation with CBD and donepezil. Your body uses a liver enzyme called CYP2D6 to help break down donepezil. In lab dish studies, CBD appears to slow that enzyme down. If that happened in real life, donepezil could clear a little more slowly and build up, which might mean more of its typical side effects, things like nausea, diarrhea, loss of appetite, a slow heartbeat, dizziness, or trouble sleeping.

The good news is this is mostly theoretical. It comes from test-tube research, and a human study using a similar CYP2D6 drug showed CBD did not actually block it. So this may not be a big deal in practice, but since CBD products vary a lot, it's worth a quick chat with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Yamaori S, Okamoto Y, Yamamoto I, Watanabe K. Cannabidiol, a major phytocannabinoid, as a potent atypical inhibitor for CYP2D6. Drug Metab Dispos 2011;39(11):2049-56. PubMed
  2. Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed
  3. Bansal S, Zamarripa CA, Spindle TR, et al. Evaluation of Cytochrome P450-Mediated Cannabinoid-Drug Interactions in Healthy Adult Participants. Clin Pharmacol Ther 2023.
Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

2 of 2

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

Cannabidiol may increase levels of drugs that are metabolized by CYP3A4.
In vitro and animal research shows that cannabidiol inhibits CYP3A4. In human studies and case reports, cannabidiol has been associated with an increase in plasma levels of the CYP3A4 substrates zonisamide, tacrolimus, everolimus, citalopram, midazolam, and methadone.
Severity Moderate Likelihood Probable Evidence A

Interaction 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..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for these two. Your body uses a liver enzyme called CYP3A4 to help clear donepezil. CBD can put the brakes on that enzyme, so donepezil may break down more slowly and build up a bit higher than usual in your system. Donepezil is the active drug already (not a prodrug), so more of it means a stronger effect, and that usually shows up as more side effects.

With donepezil, watch for things like nausea, diarrhea, loss of appetite, muscle cramps, vivid dreams, or feeling slowed down or dizzy. A noticeably slow heartbeat is also possible. This is a real, well-documented type of interaction, though how much it affects you depends on your dose and the CBD product. Please don't change anything on your own. Loop in your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Yamaori S, Ebisawa J, Okushima Y, et al. Potent inhibition of human cytochrome P450 3A isoforms by cannabidiol: role of phenolic hydroxyl groups in the resorcinol moiety. Life Sci 2011;88(15-16):730-6. PubMed
  2. Harvey DJ. Absorption, distribution, and biotransformation of the cannabinoids. Marijuana and Medicine. 1999;91-103. DOI
  3. Bornheim LM, Everhart ET, Li J, Correia MA. Characterization of cannabidiol-mediated cytochrome P450 inactivation. Biochem Pharmacol 1993;45(6):1323-31. PubMed
  4. Gaston TE, Bebin EM, Cutter GR, Liu Y, Szaflarski JP; UAB CBD Program. Interactions between cannabidiol and commonly used antiepileptic drugs. Epilepsia. 2017 Sep;58(9):1586-92. PubMed
  5. Leino AD, Emoto C, Fukuda T, Privitera M, Vinks AA, Alloway RR. Evidence of a clinically significant drug-drug interaction between cannabidiol and tacrolimus. Am J Transplant. 2019;19(10):2944-2948. PubMed
  6. Wiemer-Kruel A, Stiller B, Bast T. Cannabidiol Interacts Significantly with Everolimus-Report of a Patient with Tuberous Sclerosis Complex. Neuropediatrics. 2019. PubMed
  7. Madden K, Tanco K, Bruera E. Clinically Significant Drug-Drug Interaction Between Methadone and Cannabidiol. Pediatrics. 2020;e20193256. PubMed
  8. Anderson LL, Doohan PT, Oldfield L, et al. Citalopram and Cannabidiol: In Vitro and In Vivo Evidence of Pharmacokinetic Interactions Relevant to the Treatment of Anxiety Disorders in Young People. J Clin Psychopharmacol. 2021. PubMed
  9. Nasrin S, Watson CJW, Perez-Paramo YX, Lazarus P. Cannabinoid Metabolites as Inhibitors of Major Hepatic CYP450 Enzymes, with Implications for Cannabis-Drug Interactions. Drug Metab Dispos 2021;49(12):1070-1080. PubMed
  10. 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
  11. Bansal S, Zamarripa CA, Spindle TR, et al. Evaluation of Cytochrome P450-Mediated Cannabinoid-Drug Interactions in Healthy Adult Participants. Clin Pharmacol Ther 2023.

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

Cannabidiol (cbd) Also Interacts With Other Medications

Cannabidiol (cbd) has 1,050 moderate known drug interactions in our database — the Donepezil one above is among them. If you take anything else, check it against the full list below.

Moderate 1,050 No known interaction 1,780 (incl. Donepezil)
Taking anything else?

Check Another of Your Medications Against Cannabidiol (cbd)

Covers the 2,830 medications we’ve checked against Cannabidiol (cbd). Pick one to open its full report.

From our Q&A

Questions About Cannabidiol (cbd) or Donepezil

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cannabidiol (cbd) or Donepezil, 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 Donepezil

This page covers Cannabidiol (cbd) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Donepezil page lists 173 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), 1,3-dmaa (moderate) and Acacia Rigidula (moderate).

By severity: 3 major · 127 moderate · 43 minor.

From our pharmacist’s overview on the Donepezil page

“If you or a loved one takes donepezil (Aricept) for Alzheimer's disease, this is a list worth reading with real care, starting with the three major-rated entries: grapefruit, St. John's wort, and activated charcoal.”

Reviewed by 2 · Jul 18, 2026

Open the Donepezil interaction page

How much people look this up

Where Cannabidiol (cbd) and Donepezil 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 Cannabidiol (cbd)
Top half

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

29 days ago today
Medication Donepezil
Steady interest

#1,793 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 Cannabidiol (cbd)

What is Cannabidiol (cbd)?

  • Anxiety and stress
  • Sleep problems
  • Chronic pain
  • Certain seizure disorders
  • Inflammation

CBD is a compound from the cannabis (hemp) plant that does not cause a 'high.' It has strong evidence only for certain rare seizure disorders (as a prescription drug), while most other popular uses are still backed by limited or early research. Product quality varies a lot, so talk with your pharmacist or doctor before using it, especially if you take other medicines.

Read the full Cannabidiol (cbd) monograph & all interactions
Medication

About Donepezil

What Is Donepezil Used For?

Brand name: Aricept

Donepezil is used to treat dementia of the Alzheimer's type. It has been shown to be effective across all stages — mild, moderate, and severe Alzheimer's disease.

It can help with memory, thinking, and daily functioning, though it works differently for each person. Donepezil does not cure Alzheimer's disease or stop the disease from progressing.

See full Donepezil drug information
Keep checking

Other Drugs & Cannabidiol (cbd)

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

0Major
1,050Moderate
0Minor
1,779No known interaction
1,050 Moderate 1,779 No interaction
Moderate

1,050 interactions

Showing 60 of 1,050 moderate interactions — see all 1,050 on the Cannabidiol (cbd) page.

No interaction 1,779 drugs checked — show the list

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

Showing the 60 most looked-up of 1,779 medications checked with no known interaction — see the full Cannabidiol (cbd) list.

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

Can you take Cannabidiol (cbd) with Donepezil?
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 2 interactions listed for Cannabidiol (cbd) and Donepezil?
Donepezil belongs to more than one drug category, and Cannabidiol (cbd) 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 Cannabidiol (cbd) and Donepezil 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 Donepezil and Cannabidiol (cbd)?

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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.