Herb & supplement monograph

Licorice Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS ·Updated July 2026

What is this page for?

First and foremost: how Licorice interacts with medications. The heart of this page is the interaction list — every drug Licorice is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Licorice is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

Check Licorice against your medication

Add one medication

✓ Supplement

Licorice

1 Your medication

Start typing any prescription or over-the-counter drug name.

Reviewed by licensed pharmacists Sourced from Natural Medicines

On this page

Licorice Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Licorice drug interaction appears low for most people, though licorice deserves more respect than many supplements. None of the listed interactions are rated major, and nearly all are graded as only possible, resting on lab, animal, or limited human evidence rather than proven harm.

Interactions deserving the most attention

The concerns with the best human backing involve blood pressure medications, since licorice has been shown to raise blood pressure in a dose-dependent way. Because licorice can also drive potassium loss, combining it with diuretics or digoxin raises the risk of low potassium and, with digoxin, heart-related toxicity. Animal research suggests licorice may speed the body's clearance of warfarin, so we advise people on this blood thinner to avoid licorice. Case reports also suggest licorice can boost the effects and side effects of oral corticosteroids.

What the rest of the list means

The long list of interacting medications looks daunting, but most entries come from lab studies showing licorice might affect enzymes or transporters the body uses to process medicines. Many of these predicted effects have never been confirmed in people, and where human testing exists, the changes were modest. A big number here reflects caution, not proven danger with every drug.

Check your medications against Licorice

Based on HelloPharmacist’s Licorice interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Licorice

1041 medications have a known interaction with Licorice, graded by severity. Select any drug for the full evidence-based detail.

Don’t want to scroll the list? Just ask.

Tell us the medications you take and we’ll check each one against Licorice using our pharmacist-reviewed interaction data.

AI summaries are generated from our Licorice interaction data for education only — always confirm with your pharmacist. How we use AI

2,830 drugs

Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
Probable. 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.
Possible. 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
Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
Each drug listed above links to the full report for that exact Licorice combination — clinical detail, likelihood, evidence level, and citations.
Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

The big picture

The kinds of drugs Licorice affects

Every type of medication (drug category) Licorice is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 18 drug categories Licorice interacts with

Antihypertensive DrugsCisplatin (platinol-aq)CorticosteroidsCytochrome P450 2b6 (cyp2b6) SubstratesCytochrome P450 2c19 (cyp2c19) SubstratesCytochrome P450 2c8 (cyp2c8) SubstratesCytochrome P450 2c9 (cyp2c9) SubstratesCytochrome P450 3a4 (cyp3a4) SubstratesDigoxin (lanoxin)Diuretic DrugsEstrogensLoop DiureticsMidazolam (versed)P-glycoprotein SubstratesPaclitaxel (abraxane, Onxol)Warfarin (coumadin)Cytochrome P450 1a2 (cyp1a2) SubstratesMethotrexate (trexall, Others)

Antihypertensive Drugs

Theoretically, licorice might reduce the effects of antihypertensive drugs.
In human research, licorice increases blood pressure in a dose-dependent manner.

Likelihood Possible Evidence B

Cisplatin (Platinol-Aq)

Theoretically, licorice might reduce the effects of cisplatin.
In animal research, licorice diminished the therapeutic efficacy of cisplatin.

Likelihood Possible Evidence D

Corticosteroids

Theoretically, concomitant use of licorice and corticosteroids might increase the side effects of corticosteroids.
Case reports suggest that concomitant use of licorice and oral corticosteroids, such as hydrocortisone, can potentiate the duration of activity and increase blood levels of corticosteroids. Additionally, in one case report, a patient with neurogenic orthostatic hypertension stabilized on fludrocortisone 0.1 mg twice daily developed pseudohyperaldosteronism after recent consumption of large amounts of black licorice.

Likelihood Possible Evidence D

Cytochrome P450 2B6 (Cyp2B6) Substrates

Theoretically, licorice might increase levels of drugs metabolized by CYP2B6.
In vitro research shows that licorice extract and glabridin, a licorice constituent, inhibit CYP2B6 isoenzymes. Licorice extract from the species G. uralensis seems to inhibit CYP2B6 isoenzymes to a greater degree than G. glabra extract in vitro. Theoretically, these species of licorice might increase levels of drugs metabolized by CYP2B6; however, these interactions have not yet been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, licorice might increase levels of drugs metabolized by CYP2C19.
In vitro, licorice extracts from the species G. glabra and G. uralensis inhibit CYP2C19 isoenzymes in vitro. Theoretically, these species of licorice might increase levels of drugs metabolized by CYP2C19; however, this interaction has not yet been reported in humans.

Likelihood Possible Evidence D

Cytochrome P450 2C8 (Cyp2C8) Substrates

Theoretically, licorice might increase levels of drugs metabolized by CYP2C8.
In vitro, licorice extract from the species G. glabra and G. uralensis inhibits CYP2C8 isoenzymes. Theoretically, these species of licorice might increase levels of drugs metabolized by CYP2C8; however, this interaction has not yet been reported in humans.

Likelihood Possible Evidence D

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.

Likelihood Possible Evidence D

Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, licorice might increase or decrease levels of drugs metabolized by CYP3A4.
Pharmacokinetic research shows that the licorice constituent glycyrrhizin, taken in a dosage of 150 mg orally twice daily for 14 days, modestly decreases the area under the concentration-time curve of midazolam by about 20%. Midazolam is a substrate of CYP3A4, suggesting that glycyrrhizin modestly induces CYP3A4 activity. Animal research also shows that licorice extract from the species G. uralensis induces CYP3A4 activity. However, licorice extract from G. glabra species appear to inhibit CYP3A4-induced metabolism of testosterone in vitro. It is thought that the G. glabra inhibits CYP3A4 due to its constituent glabridin, which is a moderate CYP3A4 inhibitor in vitro and not present in other licorice species. Until more is known, licorice should be used cautiously in people taking CYP3A4 substrates.

Likelihood Possible Evidence B

Digoxin (Lanoxin)

Theoretically, concomitant use of licorice with digoxin might increase the risk of cardiac toxicity.
Overuse or misuse of licorice with cardiac glycoside therapy might increase the risk of cardiac toxicity due to potassium loss.

Likelihood Possible Evidence D

Diuretic Drugs

Theoretically, concomitant use of licorice with diuretic drugs might increase the risk of hypokalemia.
Overuse of licorice might compound diuretic-induced potassium loss. In one case report, a 72-year-old male with a past medical history of hypertension, type 2 diabetes, hyperlipidemia, arrhythmia, stroke, and hepatic dysfunction was hospitalized with severe hypokalemia and uncontrolled hypertension due to pseudohyperaldosteronism. This was thought to be provoked by concomitant daily consumption of a product containing 225 mg of glycyrrhizin, a constituent of licorice, and hydrochlorothiazide 12.5 mg for 1 month.

Likelihood Possible Evidence D

Estrogens

Theoretically, licorice might increase or decrease the effects of estrogen therapy.
Theoretically, licorice might interfere with estrogen therapy due to estrogenic and anti-estrogenic effects.

Likelihood Possible Evidence D

Loop Diuretics

Theoretically, loop diuretics might increase the mineralocorticoid effects of licorice.
Theoretically, loop diuretics might enhance the mineralocorticoid effects of licorice by inhibiting the enzyme that converts cortisol to cortisone; however, bumetanide (Bumex) does not appear to have this effect.

Likelihood Possible Evidence D

Midazolam (Versed)

Theoretically, licorice might decrease levels of midazolam.
In humans, the licorice constituent glycyrrhizin appears to moderately induce the metabolism of midazolam. This is likely due to induction of cytochrome P450 3A4 by licorice. Until more is known, licorice should be used cautiously in people taking midazolam.

Likelihood Possible Evidence B

P-Glycoprotein Substrates

Theoretically, licorice might decrease the absorption of P-glycoprotein substrates.
In vitro research shows that licorice can increase P-glycoprotein activity.

Likelihood Possible Evidence D

Paclitaxel (Abraxane, Onxol)

Theoretically, licorice might decrease plasma levels and clinical effects of paclitaxel.
Multiple doses of licorice taken concomitantly with paclitaxel might reduce the effectiveness of paclitaxel. Animal research shows that licorice 3 grams/kg given orally for 14 days before intravenous administration of paclitaxel decreases the exposure to paclitaxel and increases its clearance. Theoretically, this occurs because licorice induces cytochrome P450 3A4 enzymes, which metabolize paclitaxel. Notably, a single dose of licorice did not affect exposure or clearance of paclitaxel.

Likelihood Possible Evidence D

Warfarin (Coumadin)

Theoretically, licorice might decrease plasma levels and clinical effects of warfarin.
Licorice seems to increase metabolism and decrease levels of warfarin in animal models. This is likely due to induction of cytochrome P450 2C9 (CYP2C9) metabolism by licorice. Advise patients taking warfarin to avoid taking licorice.

Likelihood Possible Evidence D

Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, licorice might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that licorice induces CYP1A2 enzymes.

Likelihood Possible Evidence D

Methotrexate (Trexall, Others)

Theoretically, licorice might increase levels of methotrexate.
Animal research suggests that intravenous administration of glycyrrhizin, a licorice constituent, and high-dose methotrexate may delay methotrexate excretion and increase systemic exposure, leading to transient elevations in liver enzymes and total bilirubin. This interaction has not yet been reported in humans.

Likelihood Unlikely Evidence D

Monograph

Licorice: Uses, Safety & Side Effects

Medically reviewed by Dr. Brian Staiger, PharmD, BCPS · Reviewed July 2026 ·

The bottom line

Licorice root is a traditional remedy used for sore throats, coughs, and digestive complaints, but solid human evidence is limited for most uses. Regular licorice contains glycyrrhizin, which can raise blood pressure and lower potassium when taken in large amounts or for a long time, so deglycyrrhizinated (DGL) products are often preferred. Talk to your pharmacist or doctor before using it, especially if you have high blood pressure, heart, or kidney problems.

Scientific name: Glycyrrhiza glabra
Family: Fabaceae
Part used: Root
Common forms: Tea, capsules, tablets (including DGL chewable tablets), liquid extract, lozenges, dried root, candy

People commonly use it for

Sore throat and cough
Heartburn and stomach upset
Mouth ulcers and digestive complaints
Inflammation
Traditional tonic/adrenal support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance

OverallUse caution

Generally fine in small food amounts, but glycyrrhizin can cause serious problems with high doses or long-term use.

PregnancyUnsafe

When used orally. Licorice has abortifacient, estrogenic, and steroid effects. It can also cause uterine stimulation. Heavy consumption of licorice, e...

Read the full pregnancy detail

BreastfeedingInsufficient reliable information

Insufficient reliable information available; avoid using.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Licorice comes from the root of the Glycyrrhiza glabra plant (and some related species). It grows in parts of Europe, Asia, and the Mediterranean region. The root has a naturally sweet taste and has been used in traditional medicine for many centuries.

Today, people take licorice as a tea, capsule, chewable tablet, liquid extract, lozenge, or candy. It is popularly used to soothe sore throats and coughs and to ease digestive discomfort.

One important point: licorice naturally contains a compound called glycyrrhizin (also called glycyrrhizic acid). This compound can cause harmful effects in large amounts. Because of this, licorice is often processed to remove most of the glycyrrhizin, creating DGL (deglycyrrhizinated licorice), which is considered safer for regular use.

How it works

The most studied active compound in licorice is glycyrrhizin (glycyrrhizic acid). In the body it is broken down to a substance that affects an enzyme involved in handling the hormone cortisol. This can lead to the body holding onto sodium and water and losing potassium, which is why large amounts can raise blood pressure.

Licorice also contains flavonoids and other plant compounds that, in laboratory and animal studies, appear to have anti-inflammatory, soothing, and possible antimicrobial actions. It may also help form a protective coating in the digestive tract.

It is important to know that much of this information comes from laboratory and animal research. These mechanisms do not guarantee the same effects in humans.

Effectiveness

Does Licorice work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by Dr. Brian Staiger, PharmD.

Evidence overview · 48 uses evaluated

2 Possibly effective 46 Insufficient evidence

How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.

2Likely EffectiveGood evidence, though not yet conclusive.

3Possibly EffectiveSome evidence suggests a benefit.

4Possibly IneffectiveSome evidence it may not help.

5Likely IneffectiveFairly strong evidence it doesn’t help.

6IneffectiveStrong evidence it doesn’t work.

7Insufficient Reliable Evidence to RateToo little research to say either way.

Possibly Effective Atopic dermatitis (eczema)