Drug & supplement interaction

Gamma-hydroxybutyrate (ghb) + Diclofenac epolamine

Diclofenac epolamine brand names: Flector, Licart.

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

Gamma-hydroxybutyrate (ghb) has a minor interaction with Diclofenac epolamine. 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 epolamine

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 prescription form for narcolepsy, it's a dangerous, illegal central nervous system depressant, so this combination really shouldn't be happening in the first place.

That said, here's what the science actually shows. Flector and Licart deliver diclofenac, an anti-inflammatory used for pain, through a patch. In an animal study, diclofenac slightly lowered GHB levels in the blood and brain, possibly by blocking the transporters that carry GHB. Worryingly, it also seemed to worsen GHB's breathing slowdown. But a human study with the prescription form found no meaningful interaction, and the topical patch puts very little diclofenac into your bloodstream. The bigger concern by far is GHB itself. Please talk with your pharmacist or doctor.

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 epolamine 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 epolamine)
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.

Everything else you take

See Every Supplement That Interacts With Diclofenac epolamine

This page covers Gamma-hydroxybutyrate (ghb) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Diclofenac epolamine page lists 292 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 6 major · 259 moderate · 27 minor.

From our pharmacist’s overview on the Diclofenac epolamine page

“Even as a patch, diclofenac epolamine (Flector, Licart) is still an NSAID that reaches the bloodstream, and its 292 supplement interactions call for genuine care, six of them rated major. The bulk of the list, 202 ingredients, thins the blood or slows clotting, which stacks onto an NSAID's built-in bleeding risk.”

Reviewed by 2 · Jul 18, 2026

Open the Diclofenac epolamine interaction page

How much people look this up

Where Gamma-hydroxybutyrate (ghb) and Diclofenac epolamine 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

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

29 days ago today
Medication Diclofenac epolamine
Top half

#752 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
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 epolamine, 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 epolamine supplement interactions › Every supplement checked against Diclofenac epolamine, ranked by severity 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 epolamine Together: Common Questions

Can you take Gamma-hydroxybutyrate (ghb) with Diclofenac epolamine?
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 epolamine 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

Still Have a Question About Diclofenac epolamine and Gamma-hydroxybutyrate (ghb)?

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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.