Outcome
    Moderate Evidence

    DGL Licorice for Gut Barrier Integrity

    DGL thickens the gastric mucus layer and improves dyspepsia symptoms, working on the barrier rather than by suppressing acid.

    Overview

    Deglycyrrhizinated licorice, or DGL, is licorice with glycyrrhizin removed, which strips out the compound responsible for licorice blood pressure and potassium effects while retaining the flavonoid fraction thought to act on gastric mucosa. An Irish Medical Journal study examined deglycyrrhizinated liquorice in chronic duodenal ulcer, one of the earliest clinical investigations of mucosal protection with this preparation.
    More recently, a randomised, double-blind, placebo-controlled trial of a licorice flavonoid extract in functional dyspepsia found symptomatic benefit, supporting an effect on upper gastrointestinal comfort. Gut barrier integrity itself is rarely measured directly in these trials. The evidence concerns mucosal healing and symptom relief, from which barrier effects are inferred. The older ulcer literature also predates modern trial standards and the discovery of Helicobacter pylori as the dominant cause.

    How It Works

    DGL is described as cytoprotective rather than acid-suppressing. It appears to stimulate mucus secretion from gastric epithelium and increase the quantity and quality of the mucus layer, the physical barrier separating epithelium from luminal acid and pepsin. It has also been reported to increase mucosal prostaglandin production, which drives bicarbonate secretion and mucosal blood flow, the same protective pathway NSAIDs suppress.
    Licorice flavonoids, including glabridin and licochalcone A, contribute antioxidant and anti-inflammatory activity in gastric mucosa, and some show activity against Helicobacter pylori in laboratory work. Removing glycyrrhizin is what makes chronic use plausible: glycyrrhizin inhibits 11-beta-hydroxysteroid dehydrogenase type 2, producing a pseudoaldosteronism syndrome of hypertension, hypokalaemia and oedema. The deglycyrrhizinated form retains the flavonoids without that liability.

    Dosing & Protocol

    The usual regimen is 380 to 760 mg of DGL chewed 20 minutes before meals, two or three times daily. Chewable tablets are used deliberately: mixing DGL with saliva is thought to matter for its mucosal action, so swallowing capsules whole may not be equivalent. Courses typically run 8 to 16 weeks. Reassess at 8 weeks, and seek investigation rather than continuing indefinitely if symptoms persist.

    DGL is not whole licorice

    Ordinary licorice root and licorice confectionery contain glycyrrhizin, which raises blood pressure and lowers potassium. Only deglycyrrhizinated products are suitable for regular use.

    Evidence

    Two linked studies support this pairing: a 1985 Irish Medical Journal study of deglycyrrhizinated liquorice in chronic duodenal ulcer, and a 2012 Evidence-Based Complementary and Alternative Medicine randomised, double-blind, placebo-controlled trial of a licorice flavonoid extract in functional dyspepsia. The modern randomised trial is the stronger evidence. The 1985 study predates current methodological standards and the Helicobacter pylori era. Neither measured barrier integrity directly.

    Studies linked to this pairing.

    Efficacy of a licorice flavonoid extract (Glavonoid) in functional dyspepsia: a randomized, double-blind, placebo-controlled trial

    Score: 6/10
    2012
    rct
    n=50

    Raveendra KR, Jayachandra, Srinivasa V

    A standardised licorice flavonoid extract significantly reduced total dyspepsia symptom scores versus placebo.

    View source

    Deglycyrrhizinated liquorice in the treatment of chronic duodenal ulcer

    Score: 4/10
    1985
    rct
    n=100

    Kassir ZA

    DGL produced ulcer healing comparable to cimetidine with fewer relapses at one year.

    View source

    Safety

    DGL is well tolerated precisely because glycyrrhizin has been removed. Reported effects are minor: mild nausea or a taste some people dislike. The safety story is really about product selection. Whole licorice root causes pseudoaldosteronism with hypertension, hypokalaemia, oedema and, at extremes, cardiac arrhythmia, and cases have followed heavy licorice confectionery consumption. Verify the label says deglycyrrhizinated, and avoid whole licorice in hypertension, heart failure, kidney disease and pregnancy.

    Some symptoms need investigation, not supplements

    Difficulty swallowing, vomiting, weight loss, anaemia, black stools or symptoms starting after age 50 require endoscopy rather than self-treatment.

    Interactions & Conflicts

    DGL itself has few interactions. The critical distinction is with glycyrrhizin-containing licorice, which interacts substantially with diuretics, corticosteroids, digoxin and antihypertensives through potassium loss and mineralocorticoid effects. The most important practical conflict for DGL is diagnostic: it relieves symptoms without treating Helicobacter pylori infection, so masking symptoms can delay eradication of a treatable cause of ulceration.
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    References

    Frequently Asked Questions

    Medical Disclaimer

    The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

    Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.