Home Ingredients DGL Licorice (Deglycyrrhizinated Licorice)
Gut Health

DGL Licorice (Deglycyrrhizinated Licorice)

Glycyrrhiza glabra
Evidence Level
Limited
3 Clinical Trials
4 Documented Benefits
2/5 Evidence Score

DGL is a processed form of licorice root in which most of the glycyrrhizin has been removed, leaving the flavonoids, chalcones, and polysaccharides that support the gastric mucosa without raising blood pressure or depleting potassium the way whole licorice can. Traditionally chewed before meals or taken as tablets, DGL has been used for decades in functional dyspepsia, indigestion, mild reflux symptoms, and supportive care alongside ulcer therapy. Modern flavonoid-rich extracts of Glycyrrhiza glabra (such as GutGard®) have been studied in randomized trials of functional dyspepsia. By removing glycyrrhizin, DGL avoids the pseudo-aldosteronism risk associated with regular licorice ingestion. In placebo-controlled trials run between 1971 and 1978, chewable DGL did not heal stomach or duodenal ulcers better than placebo, so it is best used for everyday digestive comfort rather than as a treatment for ulcers.

Studied Dose Chewable DGL: 380-760 mg 20 minutes before meals; GutGard flavonoid extract: 75 mg twice daily.
Active Compound Licorice flavonoids (liquiritin, isoliquiritin, glabridin), chalcones, and polysaccharides; glycyrrhizin removed to <2-3%.

Benefits

Supports Stomach Comfort

DGL has a long traditional use for supporting comfort after meals, helping ease occasional indigestion, fullness, and mild burning sensations associated with everyday dietary stressors.

Supported by Trial 1, Trial 2

Helps Maintain Gastric Mucosal Health

Licorice flavonoids may help maintain the protective mucus layer lining the stomach, supporting resilience of the gastric mucosa against everyday irritants. This is a laboratory and animal mechanism; the controlled trials cited here measured symptoms and ulcer healing, not the mucus layer itself.

Supported by Trial 2, Trial 3

Avoids Glycyrrhizin-Related BP Effects

Because glycyrrhizin has been largely removed, DGL is preferred over whole licorice for longer-term use, helping users obtain the soothing properties of the herb without the pseudo-aldosteronism risk of regular licorice.

Supported by Trial 1, Trial 2

May Ease Functional Dyspepsia Symptoms

One branded deglycyrrhizinated flavonoid extract, GutGard at 75 mg twice daily, produced greater reductions in dyspepsia symptom scores than placebo over 30 days, and a later placebo-controlled trial of the same extract found earlier easing of heartburn and regurgitation. That evidence belongs to the specific branded extract rather than to chewable DGL tablets, which did not outperform placebo for ulcer healing in the older trials.

Supported by Trial 1, Trial 2

Mechanism of action

1

Mucus Secretion and Mucosal Coating

Licorice flavonoids appear to increase secretion of mucin and stimulate prostaglandin-like cytoprotective pathways in the gastric epithelium, providing a physical and chemical barrier over irritated mucosa.

2

Anti-Inflammatory Flavonoid Activity

Glabridin, liquiritigenin, and related flavonoids inhibit pro-inflammatory NF-κB signaling and modulate cytokines such as TNF-α and IL-6 in gastrointestinal mucosa preclinically.

3

Helicobacter pylori Modulation

In vitro work and one randomized placebo-controlled trial of the branded GutGard extract, which tracked H. pylori stool antigen, suggest licorice flavonoids can suppress H. pylori adhesion and growth, which may contribute to the symptomatic relief seen in functional dyspepsia.

Clinical trials

1
Flavonoid Licorice Extract in Functional Dyspepsia

Randomized, double-blind, placebo-controlled trial; 75 mg flavonoid-rich G. glabra extract twice daily for 30 days

Adults with functional dyspepsia (Rome criteria)

The branded extract GutGard was associated with significantly greater reductions in total symptom score and improvement in global efficacy assessment vs placebo, with good tolerability over the 30-day intervention.

2
DGL in Chronic Duodenal Ulceration

Retrospective endoscopic survey; oral DGL tablets in patients with chronic duodenal ulcer

32 adult patients with endoscopically confirmed chronic duodenal ulcer

Endoscopic examination after a course of DGL showed ulcer healing in the surveyed group, with mucosa appearing largely normal at follow-up; an uncontrolled, non-randomized observation. The placebo-controlled trials of DGL came before it, in 1971 and 1973, and both found no advantage over placebo.

3
Double-Blind Trial of DGL in Gastric Ulcer

Double-blind randomized trial of DGL vs placebo in gastric ulcer patients

Adults with endoscopically documented gastric ulcer

No difference was found between DGL and placebo. There was no quicker healing in either group by change in ulcer area or by complete healing, and the authors concluded the study was not able to demonstrate any healing effect. A larger placebo-controlled trial in 96 gastric ulcer patients in 1978 also found no difference in healing, ulcer area or clinical improvement.

Side effects and drug interactions

Common Potential side effects

Generally well tolerated; mild GI upset or loose stools are occasionally reported.
Authentic DGL avoids the BP elevation and hypokalemia risks of regular licorice.
Rare allergic reactions to licorice constituents can occur.
Long-term safety data beyond several months of typical use are limited. Persistent or severe stomach pain, heartburn that keeps returning, vomiting, black stools or unexplained weight loss need a doctor, since ulcers caused by H. pylori or NSAIDs have specific treatments that DGL does not replace.

Important Drug interactions

May theoretically reduce absorption of medications taken at the same time due to mucosal coating.
Use caution with corticosteroids, since even residual glycyrrhizin can amplify steroid effects.
Discuss with a clinician if combining with diuretics, antihypertensives, or digoxin.

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Frequently asked questions about DGL Licorice (Deglycyrrhizinated Licorice)

What is DGL licorice used for?

DGL (deglycyrrhizinated licorice) is licorice with the compound glycyrrhizin removed, so it soothes the digestive tract without raising blood pressure. It is used for heartburn, indigestion, and supporting the stomach and gut lining.

Why choose DGL over regular licorice?

Regular licorice's glycyrrhizin can raise blood pressure and lower potassium with regular use. DGL removes that compound, keeping the soothing, gut-protective benefits while being safe for ongoing digestive use, including for those with blood-pressure concerns.

How much DGL should I take?

It is commonly taken as a chewable tablet of about 380 to 760 mg before meals, since chewing mixes it with saliva to coat the digestive tract. Follow product labeling.

Is DGL licorice safe?

DGL is generally well tolerated and, unlike whole licorice, does not carry the same blood-pressure and potassium risks. Long-term safety data are still limited, so check with your doctor before using it for months at a time. It is a popular natural option for occasional heartburn.

What is DGL Licorice?

DGL is a processed form of licorice root in which most of the glycyrrhizin has been removed, leaving the flavonoids, chalcones, and polysaccharides that support the gastric mucosa without raising blood pressure or depleting potassium the way whole licorice can.

What is the recommended dosage of DGL Licorice?

The clinically studied dose is Chewable DGL: 380-760 mg 20 minutes before meals; GutGard flavonoid extract: 75 mg twice daily. Always follow the product label and check with a healthcare provider for personal advice.

Is DGL Licorice safe, and does it have side effects?

For most healthy adults, DGL Licorice is well tolerated at studied doses. Reported effects can include: Generally well tolerated; mild GI upset or loose stools are occasionally reported. Authentic DGL avoids the BP elevation and hypokalemia risks of regular licorice. It may also interact with some medications. DGL Licorice is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does DGL Licorice interact with any medications?

Possible interactions include: May theoretically reduce absorption of medications taken at the same time due to mucosal coating. Use caution with corticosteroids, since even residual glycyrrhizin can amplify steroid effects. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for DGL Licorice?

NutraSmarts rates the evidence for DGL Licorice as Limited (2 out of 5). It is backed by 3 clinical trials and 7 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(7 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Raveendra KR, Jayachandra, Srinivasa V, et al. An extract of Glycyrrhiza glabra (GutGard) alleviates symptoms of functional dyspepsia: a randomized, double-blind, placebo-controlled study. Evid Based Complement Alternat Med. 2012;2012:216970. doi: 10.1155/2012/216970.PubMedUsed to support: Randomized double-blind placebo-controlled trial of 75 mg GutGard twice daily for 30 days in functional dyspepsia showing significant improvement in symptom scores vs placebo. GutGard is a specific branded deglycyrrhizinated flavonoid-rich extract, so this result belongs to that extract rather than to chewable DGL tablets.
  2. Engqvist A, von Feilitzen F, Pyk E, Reichard H. Double-blind trial of deglycyrrhizinated liquorice in gastric ulcer. Gut. 1973;14(9):711-5.PubMedUsed to support: Early double-blind crossover trial of DGL in gastric ulcer patients at 760 mg three times daily over two four-week periods. There was no quicker healing in either group, and the authors wrote that the study was not able to demonstrate any healing effect. This is a negative result, not a mixed one.
  3. Feldman H, Gilat T. A trial of deglycyrrhizinated liquorice in the treatment of duodenal ulcer. Gut. 1971;12(6):449-51.PubMedUsed to support: Double-blind placebo-controlled trial in 47 patients with active duodenal ulcer, 24 on placebo and 23 on DGL (Caved-S) for one month. No advantage of DGL over placebo was found. This is a negative result.
  4. Larkworthy W, Holgate PF. Deglycyrrhizinized liquorice in the treatment of chronic duodenal ulcer. A retrospective endoscopic survey of 32 patients. Practitioner. 1975;215(1290):787-92.PubMedUsed to support: Retrospective endoscopic survey of 32 chronic duodenal ulcer patients on DGL reporting ulcer healing on follow-up endoscopy. There was no control group and no comparison treatment, so the healing cannot be attributed to DGL.
  5. Bardhan KD, Cumberland DC, Dixon RA, et al. Clinical trial of deglycyrrhizinised liquorice in gastric ulcer. Gut. 1978;19(9):779-82..PubMedUsed to support: Ninety-six patients with gastric ulcer were randomly allocated to deglycyrrhizinised liquorice or placebo. After four weeks there were no differences between the groups in complete healing assessed by gastroscopy or radiology, in the percentage reduction in ulcer area, or in clinical improvement. This is the largest of the three placebo-controlled DGL ulcer trials and it was negative.
  6. Puram S, Suh HC, Kim SU, et al. Effect of GutGard in the Management of Helicobacter pylori: A Randomized Double Blind Placebo Controlled Study. Evid Based Complement Alternat Med. 2013;2013:263805..PubMedUsed to support: One hundred and seven adults took 150 mg daily of the branded deglycyrrhizinated Glycyrrhiza glabra extract or placebo for 60 days. H. pylori stool antigen was negative in 56 percent of the GutGard group versus 4 percent on placebo. The authors are affiliated with the ingredient manufacturer, and the result belongs to that branded extract rather than to chewable DGL tablets.
  7. Raj JP, Saxena U, Belhekar MN, et al. Efficacy and Safety of GutGard® in Managing Gastroesophageal Reflux-Related Symptoms: A Phase III, Single-Centre, Double-Blind, Randomized Placebo-Controlled Trial. Complement Med Res. 2025;32(1):26-36..PubMedUsed to support: Two hundred adults took 75 mg of the branded deglycyrrhizinated Glycyrrhiza glabra extract twice daily or placebo for 28 days. Reflux-related quality of life was better in the extract group at day 28 (p = 0.014), with earlier resolution of heartburn and regurgitation within two weeks. Sponsored by the ingredient manufacturer, and the result belongs to that branded extract.