Drug & supplement interaction

Cannabidiol (cbd) + Diclofenac Sodium

Diclofenac Sodium brand names: Voltaren XR, Voltaren, Voltaren SR, Diclo, Difenac, and others.

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

Cannabidiol (cbd) has a moderate interaction with Diclofenac Sodium. Cannabidiol may increase levels of drugs metabolized by CYP2C9.

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

Cannabidiol (cbd) and Diclofenac Sodium

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

Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

Why this applies to Diclofenac Sodium

Diclofenac Sodium falls under CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES — the group Cannabidiol (cbd) interacts with.

Cannabidiol may increase levels of drugs metabolized by CYP2C9.
In vitro and animal research shows that cannabidiol inhibits CYP2C9. In human studies, cannabidiol has been associated with an increase in plasma levels of topiramate and losartan, CYP2C9 substrates. Concomitant use of cannabidiol with CYP2C9 substrates may increase the risk for adverse effects from these substrates.
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: your body clears diclofenac mainly through a liver enzyme called CYP2C9. CBD can slow that enzyme down. When the cleanup slows, more diclofenac can linger in your bloodstream, which means its effects (and its downsides) can be amplified.

For an NSAID like diclofenac, that mostly means a higher chance of the usual irritants: stomach upset, heartburn, an upset belly, or even GI bleeding, plus possible effects on blood pressure or the kidneys with regular use. This is a real, well-studied effect (CBD has measurably raised levels of other CYP2C9 drugs in people), so it's worth taking seriously. Please don't stop or change anything on your own. Just loop in your pharmacist or doctor so they can watch for side effects or adjust as needed.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Harvey DJ. Absorption, distribution, and biotransformation of the cannabinoids. Marijuana and Medicine. 1999;91-103. DOI
  2. Bornheim LM, Everhart ET, Li J, Correia MA. Characterization of cannabidiol-mediated cytochrome P450 inactivation. Biochem Pharmacol 1993;45(6):1323-31. PubMed
  3. 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
  4. 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
  5. 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
  6. 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 Diclofenac Sodium one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,050 No known interaction 1,780 (incl. Diclofenac Sodium)
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 Diclofenac Sodium

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 Diclofenac Sodium, 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 Diclofenac Sodium

This page covers Cannabidiol (cbd) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diclofenac Sodium page lists 308 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Danshen (major) and Piracetam (major).

By severity: 7 major · 266 moderate · 35 minor.

From our pharmacist’s overview on the Diclofenac Sodium page

“Diclofenac (Voltaren), a daily mainstay for arthritis and joint pain, comes with a supplement list that calls for real vigilance. Of the 308 ingredients on file, 7 rate major, and roughly two hundred entries share a single theme: anything with blood-thinning activity adds to diclofenac's own bleeding risk, especially in the stomach.”

Reviewed by 2 · Jul 18, 2026

Open the Diclofenac Sodium interaction page

How much people look this up

Where Cannabidiol (cbd) and Diclofenac Sodium 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

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

29 days ago today
Medication Diclofenac Sodium
Top 25%

#367 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 Diclofenac

What Is Diclofenac Used For?

Brand names: Voltaren XR, Voltaren, Voltaren SR, Diclo, Difenac, Diclo SR, Voltarol, Acoflam, Defenac, Dicloflex, Diclovol, Diclozip, Fenactol, Flamrase, Volraman, Diclomax SR, Diclomax Retard, Motifene 75 mg, Voltarol 75 mg SR, Acoflam 75 SR, Defenac SR, Dexomon 75 SR, Dicloflex 75 SR, Diclovol SR, Fenactol 75 mg SR, Flamatak 75 MR, Flamrase SR, Flexotard MR 75, Rheumatac Retard 75, Rhumalgan CR, Slofenac SR, Volsaid Retard 75, Voltarol Retard, Acoflam Retard, Defenac Retard, Dexomon Retard 100, Dicloflex Retard, Diclovol Retard, Fenactol Retard 100 mg, Flamatak 100 MR, Volsaid Retard 100, Voltarol Ophtha Multidose, Voltarol Ophtha, Pennsaid, Voltaren Emulgel, Dyloject

Diclofenac sodium topical gel is used to treat actinic keratoses (AK) — rough, scaly skin patches that form after years of sun exposure. These patches are considered precancerous, meaning they can develop into skin cancer if left untreated.

This is a topical gel, meaning it is applied directly to the skin over the affected area rather than taken by mouth. It belongs to the NSAID (nonsteroidal anti-inflammatory drug) family.

See full Diclofenac 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 Diclofenac Sodium, 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 Diclofenac Sodium supplement interactions › Every supplement checked against Diclofenac Sodium, ranked by severity Diclofenac 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 Diclofenac Sodium Together: Common Questions

Can you take Cannabidiol (cbd) with Diclofenac Sodium?
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 Cannabidiol (cbd) and Diclofenac Sodium 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

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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.