Drug & supplement interaction

Gamma-hydroxybutyrate (ghb) + Diclofenac

Diclofenac brand name: Zorvolex.

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

Gamma-hydroxybutyrate (ghb) has a minor interaction with Diclofenac. Diclofenac might decrease the levels and clinical effects of GHB.

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

Gamma-hydroxybutyrate (ghb) and Diclofenac

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

Minor

DICLOFENAC (Voltaren, others)

Diclofenac might decrease the levels and clinical effects of GHB.
In an animal study, concomitant use of GHB with diclofenac reduces GHB plasma and brain concentrations, and the brain-to-plasma concentration ratio, when compared with administration of GHB alone. Concomitant administration also increased GHB-induced respiratory depression. These effects may have been due to inhibition of monocarboxylate transporters at the blood-brain barrier. However, one clinical study in healthy adults shows that concomitant use of the sodium salt of GHB, sodium oxybate, has no effect on GHB exposure or diclofenac pharmacokinetics.
Severity Minor Likelihood Unlikely Evidence A

Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans..

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

First things first: GHB is not a safe supplement. Outside of the tightly controlled prescription form for narcolepsy, it is a dangerous central nervous system depressant that can cause coma and stopped breathing. So my biggest concern here isn't really the diclofenac at all. Please don't use street or non-prescription GHB.

As for the interaction on file, it's rated minor and unlikely. The signal comes mostly from an animal study where diclofenac seemed to lower GHB levels in the blood and brain, possibly by blocking a transporter that moves GHB around. A human study using the prescription form (sodium oxybate) showed no real effect on either drug. Diclofenac itself isn't a prodrug, so its usual pain relief shouldn't change. Still, the animal data hinted at more breathing slowdown, so if you've been prescribed sodium oxybate, run any diclofenac use past your pharmacist or doctor first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Xyrem. Jazz Pharmaceuticals, Inc. Palo Alto, CA. March 2022.
  2. Rodriguez-Cruz V, Ren T, Morris ME. Drug-drug interaction between diclofenac and gamma-hydroxybutyric acid. Biopharm Drug Dispos 2021;42(8):351-358. 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

Gamma-hydroxybutyrate (ghb) Also Interacts With Other Medications

Gamma-hydroxybutyrate (ghb) has 249 major, 21 moderate, 4 minor known drug interactions in our database — the Diclofenac one above is one of them. If you take anything else, check it against the full list below.

Major 249 Moderate 21 Minor 4 No known interaction 2,556 (incl. Diclofenac)
Taking anything else?

Check Another of Your Medications Against Gamma-hydroxybutyrate (ghb)

Covers the 2,830 medications we’ve checked against Gamma-hydroxybutyrate (ghb). Pick one to open its full report.

From our Q&A

Questions About Gamma-hydroxybutyrate (ghb) or Diclofenac

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Gamma-hydroxybutyrate (ghb) or Diclofenac, 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

This page covers Gamma-hydroxybutyrate (ghb) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diclofenac page lists 306 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 · 265 moderate · 34 minor.

From our pharmacist’s overview on the Diclofenac page

“Diclofenac (Zorvolex) is an NSAID pain reliever that already stresses the stomach lining and kidneys on its own, so treat this list as a real safety issue, not fine print. Two thirds of the 306 supplements on file can thin the blood or slow clotting, and stacked on an NSAID that raises the odds of stomach bleeding.”

Reviewed by 2 · Jul 18, 2026

Open the Diclofenac interaction page

How much people look this up

Where Gamma-hydroxybutyrate (ghb) and Diclofenac 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 Gamma-hydroxybutyrate (ghb)
Steady interest

#1,273 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Diclofenac
Top 25%

#307 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 Gamma-hydroxybutyrate (ghb)

What is Gamma-hydroxybutyrate (ghb)?

  • Narcolepsy (cataplexy and excessive daytime sleepiness)
  • Sleep aid
  • Misused as a recreational 'party drug'
  • Bodybuilding/muscle building (unproven)
  • Alcohol withdrawal (in some countries)

GHB (gamma-hydroxybutyrate) is a powerful central nervous system depressant that is NOT a safe dietary supplement. In the U.S. it is a controlled substance, and only a tightly regulated prescription form (sodium oxybate) is legal for narcolepsy. Non-prescription GHB can cause coma, breathing failure, and death, and it is also a known 'date-rape' drug — it should not be taken outside of medical supervision.

Read the full Gamma-hydroxybutyrate (ghb) monograph & all interactions
Medication

About Diclofenac

What Is Diclofenac Used For?

Brand name: Zorvolex

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 & Gamma-hydroxybutyrate (ghb)

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

249Major
21Moderate
4Minor
2,555No known interaction
249 Major 21 Moderate 4 Minor 2,555 No interaction
Major

249 interactions

Showing 60 of 249 major interactions — see all 249 on the Gamma-hydroxybutyrate (ghb) page.

Moderate

21 interactions

Minor

4 interactions

No interaction 2,555 drugs checked — show the list

We also checked Gamma-hydroxybutyrate (ghb) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,555 medications checked with no known interaction — see the full Gamma-hydroxybutyrate (ghb) list.

See the full Gamma-hydroxybutyrate (ghb) interactions page
See every supplement checked against Diclofenac, 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
Gamma-hydroxybutyrate (ghb) monograph › Uses, safety, and every drug interaction in one place Diclofenac supplement interactions › Every supplement checked against Diclofenac, 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 Gamma-hydroxybutyrate (ghb) and Diclofenac Together: Common Questions

Can you take Gamma-hydroxybutyrate (ghb) with Diclofenac?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Gamma-hydroxybutyrate (ghb) and Diclofenac interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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.