Licorice - Voltaren (Diclofenac Sodium) Interaction
Herbal: Licorice
Also Known As: Glycyrrhiza echinate, Alcacuz, Bois Doux, Can Cao, Deglycyrrhized Licorice, Gan Cao, Gan Zao, Glabra, Glycyrrhizic Acid, Glycyrrhizinic Acid, Kanzo, Lakritze, Liquiritiae Radix, Liquirizia, Mulathi, Mulethi, Orozuz, Subholz, Yashtimadhu, Yashti-Madhu
Drug: Diclofenac Sodium
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
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 25, 2025
Interaction Details
Diclofenac Sodium is classified as belonging to the following category: Cytochrome P450 2C9 (Cyp2C9) Substrates
Theoretically, licorice might increase or decrease levels of drugs metabolized by CYP2C9.
There is conflicting evidence about the effect of licorice on CYP2C9 enzyme activity. In vitro research shows that extracts from the licorice species G. glabra and G. uralensis moderately inhibit CYP2C9 isoenzymes. However, evidence from an animal model shows that licorice extract from the species G. uralensis can induce hepatic CYP2C9 activity. Until more is known, licorice should be used cautiously in people taking CYP2C9 substrates.
Interaction Rating
Likelihood of Occurrence
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
References
- Kent UM, Aviram M, Rosenblat M, Hollenberg PF. The licorice root derived isoflavan glabridin inhibits the activities of human cytochrome P450S 3A4, 2B6, and 2C9. Drug Metab Dispos 2002;30:709-15..
- Mu Y, Zhang J, Zhang S, et al. Traditional Chinese medicines Wu Wei Zi (Schisandra chinensis Baill) and Gan Cao (Glycyrrhiza uralensis Fisch) activate pregnane X receptor and increase warfarin clearance in rats. J Pharmacol Exp Ther 2006;316:1369-77.
- Li G, Simmler C, Chen L, et al. Cytochrome P450 inhibition by three licorice species and fourteen licorice constituents. Eur J Pharm Sci. 2017;109:182-190.
Licorice Overview
Licorice, also known as glycyrrhiza, is a plant native to parts of Europe, Asia, and the Mediterranean region. The root of the plant has been used for centuries in traditional medicine and is often consumed in the form of candy, tea, and supplements.
Licorice has a number of purported health benefits, including the ability to soothe sore throats, reduce inflammation, and improve digestive problems. It may also have antiviral and antibacterial properties.
Licorice naturally contains glycyrrhizin, or glycyrrhizic acid, which can have toxic effects if consumed in large amounts. However, licorice can be processed to remove glycyrrhizin, resulting in DGL (deglycyrrhizinated licorice). Many dietary supplements that contain deglycyrrhizinated licorice are often simply named 'DGL'.
Diclofenac Sodium Overview
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Diclofenac capsules (Zipsor, Zorvolex) and tablets (Cataflam) are used to relieve mild to moderate pain. Diclofenac extended-release tablets (Voltaren XR), tablets (Cataflam), and delayed-release tablets (available generically) are used to relieve pain, tenderness, swelling, and stiffness caused by osteoarthritis (arthritis caused by a breakdown of the lining of the joints), and rheumatoid arthritis (arthritis caused by swelling of the lining of the joints). Diclofenac extended-release tablets and delayed-release tablets are also used to treat ankylosing spondylitis (arthritis that mainly affects the spine). Diclofenac tablets (Cataflam) are also used to treat painful menstrual periods. Diclofenac solution (Cambia) is used to treat migraine headaches in adults, but cannot be used to prevent migraines or to treat other types of headaches. Diclofenac is in a class of medications called NSAIDs. It works by stopping the body's production of a substance that causes pain, fever, and inflammation.
Licorice - More Interactions
Licorice interacts with 1011 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
| Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
| Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
| Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
| Unknown | No interactions have been reported or no interaction data is currently available. |
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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
Drug descriptions are provided by MedlinePlus.
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In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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