Drug & supplement interaction

Cannabinol (cbn) + 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

Cannabinol (cbn) has a moderate interaction with Diclofenac Sodium. Theoretically, cannabinol might increase the levels and clinical effects of CYP2C9 substrates.

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

Cannabinol (cbn) 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 Cannabinol (cbn) interacts with.

Theoretically, cannabinol might increase the levels and clinical effects of CYP2C9 substrates.
In vitro research shows that cannabinol potently inhibits CYP2C9 enzymes. So far, this interaction 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: your body relies on an enzyme called CYP2C9 to break down diclofenac. Lab studies suggest CBN can block that enzyme. If it does, diclofenac could clear more slowly and build up in your system, which may nudge up both its pain relief and its side effects. With an NSAID like diclofenac, that could mean stomach upset or pain, heartburn, a higher risk of stomach bleeding, fluid retention, or stress on the kidneys and blood pressure.

The important caveat: this is only seen in test-tube research, never reported in real people, so it's theoretical. I wouldn't panic, but I would loop in your pharmacist or doctor before pairing them, especially if you take diclofenac regularly.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. 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

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

Cannabinol (cbn) Also Interacts With Other Medications

Cannabinol (cbn) has 388 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 388 No known interaction 2,442 (incl. Diclofenac Sodium)
Taking anything else?

Check Another of Your Medications Against Cannabinol (cbn)

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

From our Q&A

Questions About Cannabinol (cbn) 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 Cannabinol (cbn) 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 Cannabinol (cbn) 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 Cannabinol (cbn) 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 Cannabinol (cbn)
Top half

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

29 days ago today
Medication Diclofenac Sodium
Top 25%

#366 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 Cannabinol (cbn)

What is Cannabinol (cbn)?

  • Sleep support
  • Relaxation
  • Pain or discomfort
  • Appetite-related concerns

Cannabinol (CBN) is a minor cannabinoid found in the cannabis plant, often marketed as a 'sleep' aid, but solid human research is very limited. Because it comes from cannabis and product quality varies widely, talk with your pharmacist or doctor before trying it, and avoid it during pregnancy and breastfeeding.

Read the full Cannabinol (cbn) 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 & Cannabinol (cbn)

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

0Major
388Moderate
0Minor
2,441No known interaction
388 Moderate 2,441 No interaction
Moderate

388 interactions

Showing 60 of 388 moderate interactions — see all 388 on the Cannabinol (cbn) page.

No interaction 2,441 drugs checked — show the list

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

Showing the 60 most looked-up of 2,441 medications checked with no known interaction — see the full Cannabinol (cbn) list.

See the full Cannabinol (cbn) 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
Cannabinol (cbn) 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 Cannabinol (cbn) and Diclofenac Sodium Together: Common Questions

Can you take Cannabinol (cbn) 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 Cannabinol (cbn) 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

Still Have a Question About Diclofenac Sodium and Cannabinol (cbn)?

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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.