NutriDex

The Supplement Research Compendium
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DGL (Deglycyrrhizinated Licorice)

Glycyrrhiza glabra

Licorice with the blood-pressure-raising glycyrrhizin removed, for stomach comfort.

Moderate evidence 🛡️Gut & Immune

✚ Updated · How we grade evidence

Evidence tier
Moderate
Research weight
Citations
7 verified / 7
Classification
Gut & Immune
❝
What the evidence says. Graded moderate: several short, single-centre RCTs of one standardized extract (GutGard) show real symptom relief in dyspepsia and reflux, but nearly all are small and manufacturer-funded, and a 2025 meta-analysis found licorice's effect on actual ulcer healing was not statistically significant. (Moderate evidence: Several controlled trials; effects real but modest or context-dependent.)

What is DGL (Deglycyrrhizinated Licorice)?

DGL (Deglycyrrhizinated Licorice) (Glycyrrhiza glabra) is a gut and immune supplement used for ease functional dyspepsia. NutriDex grades the human evidence as Moderate. DGL is licorice root processed to strip out glycyrrhizin, the compound that raises blood pressure and depletes potassium, leaving the flavonoids thought to soothe the gut. The best evidence is for functional dyspepsia and reflux: in placebo-controlled trials of a standardized extract (GutGard, 150 mg/day), total symptom and Nepean dyspepsia scores fell significantly over 30 days, and reflux-related heartburn and regurgitation improved over 28 days. A small randomized trial suggested it lowered H. pylori load, and old uncontrolled work found DGL mouthwash sped canker-sore healing. However, most trials enrolled only 50–200 people, ran at one site, and were funded by the extract's maker; a 2025 systematic review of 9 trials (618 people) found licorice improved ulcer-healing and pain numerically but not significantly. So DGL is plausibly helpful for indigestion comfort, but the proof is thin and likely overstated by industry sponsorship.

Purported Benefits

✓Ease functional dyspepsia
✓Soothe heartburn & reflux symptoms
✓Speed canker-sore healing
✓Protect gastric lining from aspirin

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Ease functional dyspepsia symptomsStandardized GutGard RCT (n=50) cut dyspepsia scores vs placebo; single-site and manufacturer-funded. Preliminary ↑ benefit · moderate 1
Soothe heartburn and reflux symptomsGutGard RCT (n=200) improved heartburn and regurgitation over 28 days; industry-sponsored, needs replication. Preliminary ↑ benefit · moderate 1
Reduce H. pylori loadOne RCT (n=107) cleared H. pylori stool antigen in 56% vs 4% placebo; single small sponsored trial. Preliminary ↑ benefit 1
Heal peptic/duodenal ulcers2025 meta-analysis (9 trials, 618) found ulcer healing improved numerically but not significantly; older data uncontrolled. Mixed ↔ mixed · small 2
Speed canker-sore (aphthous ulcer) healingOld uncontrolled DGL-mouthwash trial reported fast healing in 15 of 20 patients; no placebo control. Preliminary ↑ benefit 1
Protect gastric lining from aspirin1979 study found DGL reduced aspirin-induced fecal blood loss; very old, small human data. Preliminary ↑ benefit 1

Dosing & Compounds

Typical Dose
Standardized flavonoid extract (e.g. GutGard) 75 mg twice daily, or 380–760 mg chewable DGL before meals; glycyrrhizin should be <3%.
Active Compounds
Glabridin & licorice flavonoidsLiquiritin / isoliquiritinGlycyrrhizin (removed to <3%)

Safety & Cautions

True DGL (glycyrrhizin <3%) is well tolerated; unlike whole licorice it should not cause the high blood pressure, low potassium, fluid retention or pseudo-aldosteronism seen with glycyrrhizin. Mild GI upset is the main complaint. Risk rises if a product is mislabelled or you take ordinary (non-DGL) licorice: that can interact dangerously with antihypertensives, diuretics, digoxin, corticosteroids and warfarin, and worsen heart, kidney or liver disease and low potassium. Pregnant people should avoid high licorice intake; check that any product is genuinely deglycyrrhizinated. Educational only — always check with your doctor or pharmacist before combining DGL (Deglycyrrhizinated Licorice) with any medicine.

Key Studies

Meta-analysis Khorasani 2025 ✓ Full text
Meta-analysis of 9 trials (618 patients): licorice improved ulcer healing and pain numerically but not significantly.
RCT Raj 2025 ✓ PubMed
GutGard 150mg/day improved reflux-related heartburn (p=0.005) and regurgitation vs placebo over 28 days (n=200).
RCT Raveendra 2012 ✓ PubMed
GutGard 75mg twice daily for 30 days significantly cut total dyspepsia and Nepean index scores vs placebo (n=50).
RCT Puram 2013 ✓ PubMed
GutGard 150mg/day for 60 days cleared H. pylori stool antigen in 56% vs 4% on placebo (n=107).
RCT Das 1989 ✓ PubMed
Uncontrolled trial: DGL mouthwash gave 50–75% improvement within 1 day in 15 of 20 aphthous-ulcer patients, healing by day 3.
RCT Rees 1979 ✓ PubMed
DGL 350mg taken with each aspirin dose reduced aspirin-induced faecal blood loss in humans; protected gastric mucosa in rats.
Cohort Larkworthy 1975 ✓ PubMed
Endoscopic survey: deglycyrrhizinated licorice associated with healing in patients with chronic duodenal ulcer.
7 sources cited · 7 verified Search all studies on PubMed ↗

Common questions about DGL (Deglycyrrhizinated Licorice)

What is DGL (Deglycyrrhizinated Licorice) used for?

DGL (Deglycyrrhizinated Licorice) is most often taken for Ease functional dyspepsia, Soothe heartburn & reflux symptoms, Speed canker-sore healing, Protect gastric lining from aspirin. Licorice with the blood-pressure-raising glycyrrhizin removed, for stomach comfort.

Does DGL (Deglycyrrhizinated Licorice) work — what does the evidence say?

Moderate evidence. Several controlled trials; effects real but modest or context-dependent. DGL is licorice root processed to strip out glycyrrhizin, the compound that raises blood pressure and depletes potassium, leaving the flavonoids thought to soothe the gut. The best evidence is for functional dyspepsia and reflux: in placebo-controlled trials of a standardized extract (GutGard, 150 mg/day), total symptom and Nepean dyspepsia scores fell significantly over 30 days, and reflux-related heartburn and regurgitation improved over 28 days. A small randomized trial suggested it lowered H. pylori load, and old uncontrolled work found DGL mouthwash sped canker-sore healing. However, most trials enrolled only 50–200 people, ran at one site, and were funded by the extract's maker; a 2025 systematic review of 9 trials (618 people) found licorice improved ulcer-healing and pain numerically but not significantly. So DGL is plausibly helpful for indigestion comfort, but the proof is thin and likely overstated by industry sponsorship.

What is the typical dose of DGL (Deglycyrrhizinated Licorice)?

Standardized flavonoid extract (e.g. GutGard) 75 mg twice daily, or 380–760 mg chewable DGL before meals; glycyrrhizin should be <3%.

Is DGL (Deglycyrrhizinated Licorice) safe? Any cautions or side effects?

True DGL (glycyrrhizin <3%) is well tolerated; unlike whole licorice it should not cause the high blood pressure, low potassium, fluid retention or pseudo-aldosteronism seen with glycyrrhizin. Mild GI upset is the main complaint. Risk rises if a product is mislabelled or you take ordinary (non-DGL) licorice: that can interact dangerously with antihypertensives, diuretics, digoxin, corticosteroids and warfarin, and worsen heart, kidney or liver disease and low potassium. Pregnant people should avoid high licorice intake; check that any product is genuinely deglycyrrhizinated.

How many studies support DGL (Deglycyrrhizinated Licorice)?

NutriDex cites 7 sources for DGL (Deglycyrrhizinated Licorice), graded "Moderate".

Cite this page
APA

Peh, D. (2026). DGL (Deglycyrrhizinated Licorice) (Glycyrrhiza glabra): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/dgl-licorice

BibTeX
@misc{nutridex_dgl_licorice,
  author       = {Peh, Daryl},
  title        = {DGL (Deglycyrrhizinated Licorice) (Glycyrrhiza glabra): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/dgl-licorice},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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