Glycyrrhiza glabra (root)

Liquorice root

Liquorice root has limited evidence for indigestion and heartburn: the trials that exist tested a proprietary deglycyrrhizinated (DGL) extract, are small and have not been repeated by independent groups. Ordinary liquorice that still contains glycyrrhizin is a different matter, because it can raise blood pressure and lower potassium at low daily intakes and has caused dangerous heart rhythm problems.

If you have high blood pressure, heart, kidney or liver disease, or are pregnant, avoid glycyrrhizin-containing liquorice, and check the label for "deglycyrrhizinated" before buying.

Written by

Healthy and Herbal editorial team

Reviewed by

Healthy and Herbal editors

Updated

10 October 2026

At a glance

Last reviewed 10 October 2026

Evidence

Limited

Best for

Indigestion and heartburn

Typical form & use

DGL extract, 75 mg twice daily

Onset

2 weeks

Safety

Raises blood pressure, lowers potassium; not for pregnancy. 5 known interactions, most serious with blood pressure medication.

Check with your medications →

What it's used for

Evidence is rated per use. The same ingredient can be strong for one thing and traditional for another.

Use	Evidence	What the research shows
Functional indigestion (dyspepsia)Compare remedies for digestion →	Limited	One randomised placebo-controlled trial of 50 people with functional dyspepsia found that a Glycyrrhiza glabra extract (75 mg twice daily for 30 days) reduced total symptom scores at days 15 and 30 compared with placebo. The 2023 Cochrane review of non-Chinese herbal medicines rated this single-study result as moderate-certainty, but a single small trial cannot settle the question. NCCIH says it is unclear whether liquorice alone has an effect on digestive symptoms.^1,2,7
Heartburn and reflux symptomsCompare remedies for acid reflux & heartburn →	Limited	One 200-person, 28-day placebo-controlled trial of a deglycyrrhizinated extract (glycyrrhizin 3% or less) reported earlier relief of heartburn and regurgitation, and better reflux-related quality of life, than placebo. It is a single-centre trial of one branded extract and we found no independent replication.³
Cough with a coldCompare remedies for coughs & colds →	Traditional	The EU herbal regulator lists liquorice root as a traditional expectorant for cough with a cold, and for digestive burning and dyspepsia, on the basis of long-standing use alone, not clinical trials. We did not find or review modern cough trials.⁶
Recurrent mouth ulcers (rinse or gargle)	Limited	NCCIH reports that a liquorice mouth rinse or gargle might reduce ulcer size and pain in recurrent canker sores, but states there is not enough high-quality evidence to support liquorice for any health condition. We did not read the individual trials, so this rests on NCCIH's summary.⁷

How much

Ranges below are what studies used and what supplements commonly contain. They are not a recommendation for you. Start at the low end.

Studied DGL dose

75 mg twice daily^2,3

The dose of the extract used in the 30-day functional dyspepsia trial. The reflux trial ran for 28 days; its dose is not given in the abstract we read. Doses are not interchangeable between brands.

EU monograph dose

Tea 1.5–2 g, 2–4 times daily⁶

For digestive symptoms in adults: 1.5–2 g of comminuted root in 150 ml boiling water after meals (3–8 g a day), or a soft extract at 32 mg two to three times daily (maximum 160 mg a day). This is a traditional-use dose for whole root, which contains glycyrrhizin.

Duration limit

No more than 4 weeks⁶

The EU monograph says not to use liquorice medicines for more than 4 weeks for digestive symptoms, and to see a doctor if symptoms last beyond 2 weeks. It reports overdose effects (water retention, low potassium, high blood pressure, heart rhythm disorders) with use beyond 4 weeks or at high intakes.

Glycyrrhizin intake

100 mg a day raised blood pressure⁵

In a randomised crossover trial of 28 healthy young adults, 100 mg of glycyrrhizic acid a day for 2 weeks raised home systolic blood pressure by 3.1 mm Hg and suppressed renin and aldosterone. The WHO had suggested 100 mg a day was unlikely to cause harm; the authors say that limit may need rethinking.

Timing · The EU monograph says to take the tea as one cup after meals. No source we read gave timing for DGL capsules or tablets.With food? · Only the EU monograph's advice to drink the tea after meals. No source we read addressed capsules with or without food.How long to trial · The EU monograph says to see a doctor or qualified practitioner if digestive symptoms persist beyond 2 weeks, and not to use liquorice for more than 4 weeks. In the reflux trial, symptom differences appeared within 2 weeks.

How people take it

DGL extract (capsule or chewable)75 mg twice daily (trial dose)Deglycyrrhizinated: glycyrrhizin removed or reduced. The trials used one flavonoid-rich extract with glycyrrhizin at 3% or less. NCCIH says DGL products might be safe for up to 4 months.

Whole root tea1.5–2 g in 150 ml, 2–4 times daily (EU)Contains glycyrrhizin, so the blood pressure and potassium risks below apply. Traditional use only in the EU monograph.

Liquorice sweets and confectioneryVaries by productNot a supplement, but a common source of glycyrrhizin. The EU monograph says people using liquorice medicines should not take other liquorice-containing products. NCCIH notes many US products sold as licorice contain anise oil instead.

Safety

Who should avoid

High blood pressure, heart, kidney or liver disease — EU regulator advises against
Low potassium — glycyrrhizin lowers it further
Pregnancy — EU regulator advises against; heavy intake linked to earlier birth
Breastfeeding — EU regulator advises against, effect on infants unknown
Under 18 — not established, too little data
With diuretics, digoxin, corticosteroids or stimulant laxatives — EU regulator advises against
Long-term use — EU limit is 4 weeks for digestive symptoms
High salt intake — even small amounts of glycyrrhizin linked to serious effects (NCCIH)

Known interactions

AvoidBlood pressure medication — The EU regulator says liquorice may counteract antihypertensive drugs and should not be used with diuretics, which can also lower potassium; the 2017 meta-analysis found glycyrrhizin raised systolic blood pressure by about 5 mm Hg.

AvoidCorticosteroids (steroid tablets) — The EU regulator says not to use liquorice with corticosteroids, which can aggravate electrolyte imbalance; NCCIH also notes that interactions between licorice and corticosteroids have been reported.

AvoidDigoxin & heart-rhythm medication — The EU regulator says not to use liquorice with cardiac glycosides such as digoxin or other drugs that worsen electrolyte imbalance, because low potassium can trigger heart rhythm disorders.

AvoidSenna — The EU regulator says not to use liquorice with stimulant laxatives, which can add to potassium loss; senna is a stimulant laxative.

CautionSenna — Liquorice root, like diuretics and corticosteroids, may enhance potassium loss, which the EU monograph says means checking with a doctor before taking senna.

Questions people ask

What is the difference between DGL and ordinary liquorice?

DGL is deglycyrrhizinated: most of the glycyrrhizin has been removed. Glycyrrhizin is the compound that raises blood pressure and lowers potassium. NCCIH says DGL products might be safe for up to 4 months, whereas glycyrrhizin-containing products have caused serious effects, so check the label.

Does liquorice work for acid reflux or indigestion?

There is limited evidence. One 50-person trial and one 200-person trial of a DGL extract found better symptoms than placebo over 4 weeks or so, but they are small, short and not independently replicated. NCCIH says it is unclear whether liquorice alone helps digestive symptoms.

How much liquorice is too much?

There is no reliably safe amount for everyone. In one trial, 100 mg of glycyrrhizic acid a day, the level once thought unlikely to cause harm, raised blood pressure within 2 weeks in healthy young adults.

NCCIH says even small amounts have been linked to severe effects in people who eat a lot of salt or who have high blood pressure, heart or kidney conditions.

Is liquorice safe in pregnancy?

The EU regulator advises against it. In a Finnish study of 1,049 women, heavy glycyrrhizin intake (500 mg a week or more) was linked to a higher chance of birth before 38 weeks (odds ratio 2.5). NCCIH gives about 250 g of liquorice a week as an unsafe amount.

Sources (8)

Reader notes

Experiences and questions from readers, read by an editor before they appear. They are personal accounts, not evidence, and are not medical advice.

Last reviewed 10 October 2026 · Next review April 2027 · How we rate evidence

Liquorice root

At a glance

What it's used for

How much

How people take it

Safety

Who should avoid

Known interactions

Questions people ask

What is the difference between DGL and ordinary liquorice?

Does liquorice work for acid reflux or indigestion?

How much liquorice is too much?

Is liquorice safe in pregnancy?

Sources (8)

Reader notes

Used it? Share how it went, or ask a question.