| Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any supplement or changing your treatment plan. |
That burning feeling rising from the chest into the throat often shows up at the worst possible moment, after a calm dinner, in the middle of the night, or right when life finally slows down. For people living with acid reflux or gastroesophageal reflux disease (GERD), heartburn can feel unpredictable and exhausting. Many understandably begin looking beyond conventional medications toward herbal and natural options.
Deglycyrrhizinated licorice, commonly referred to as DGL, has attracted growing clinical interest as a complementary approach to managing reflux symptoms. But what does the evidence actually say, and is it safe? This article reviews the current research clearly and accurately, with all key claims referenced to peer-reviewed sources.
Understanding Acid Reflux and GERD
Acid reflux occurs when stomach contents, including acid, flow backward into the esophagus. The esophageal lining lacks the protective mucosa of the stomach and is not designed to handle repeated acid exposure. This leads to the hallmark symptoms of heartburn, throat irritation, chest discomfort, and a sour or bitter taste.
Common contributing factors include:
- Overeating or large meal portions
- Dysfunction or transient relaxation of the lower esophageal sphincter (LES)
- Hiatal hernia
- Obesity, smoking, and certain dietary triggers (e.g., caffeine, alcohol, spicy foods)
- Stress and impaired gastric motility
Conventional treatments primarily focus on suppressing stomach acid through proton pump inhibitors (PPIs) or H2-receptor antagonists. While effective for many patients, these medications do not directly address mucosal repair or the barrier function of the esophageal and gastric lining, an area where DGL has attracted scientific interest.
What Is Licorice Root and What Makes DGL Different?
Licorice Root (Glycyrrhiza glabra)
Licorice root comes from the plant Glycyrrhiza glabra, a leguminous herb native to Southern Europe and Western Asia that has been used in traditional medicine for millennia. Its root contains a mixture of bioactive compounds, most notably glycyrrhizin (also called glycyrrhizic acid) and a class of polyphenols called flavonoids, including glabridin.
The Importance of Deglycyrrhizination
Deglycyrrhizinated licorice (DGL) is produced by removing most of the glycyrrhizin from licorice root extract. This processing step is medically significant. Based on articles retrieved from PubMed, a 2017 meta-analysis published in the Journal of Human Hypertension (Penninkilampi et al.) found that chronic ingestion of products containing glycyrrhizic acid was associated with statistically significant increases in both systolic blood pressure (+5.45 mmHg) and diastolic blood pressure (+3.19 mmHg), as well as significant reductions in plasma potassium. A further 2024 meta-analysis and systematic review of eight randomized controlled trials published in Nutrients (Wu et al.) confirmed that licorice preparations where glycyrrhizic acid was the dominant component raised both systolic and diastolic blood pressure, whereas preparations dominated by licorice flavonoids showed no significant blood pressure effect.
By removing the majority of glycyrrhizin, DGL retains the flavonoid-rich fractions believed to support digestive health while substantially reducing the cardiovascular risks associated with whole licorice.
How DGL May Help with Acid Reflux: The Evidence
Clinical Trial Evidence
According to PubMed, the strongest recent clinical evidence for DGL in GERD comes from a Phase III, double-blind, randomized, placebo-controlled trial published in Complementary Medicine Research (Raj et al., 2025). The trial enrolled 200 participants and evaluated GutGard®, a standardized, flavonoid-rich, deglycyrrhizinated licorice root extract, over 28 days. Participants receiving the DGL extract reported significantly better quality of life at the end of the intervention period (p = 0.014) and earlier resolution of both heartburn (p = 0.005 at day 28) and regurgitation (p = 0.025 at day 7) compared to the placebo group. The authors noted symptom improvement began within two weeks of starting treatment.
It is important to note that this trial tested a specific proprietary extract standardized to a minimum of 3.5% glabridin and 10% total flavonoids with glycyrrhizin content kept below 3.0% w/w. Results may not be generalizable to all DGL formulations, which vary widely in composition and potency.
Proposed Mechanisms
DGL is not classified as an acid-suppressing agent. Researchers have proposed that its benefits in reflux may stem from supporting the mucosal barrier of the stomach and esophagus, though the precise mechanisms in humans have not been fully established. A 2019 narrative review in Current Gastroenterology Reports (Ahuja & Ahuja) noted that licorice, alongside other herbal remedies, has attracted interest due to mechanistic hypotheses around mucosal protection and motility, while acknowledging that a substantial evidence gap persists between anecdotal and empirical understanding of most non-pharmacologic treatments for esophageal symptoms.
A 2025 systematic review published in Nutrients evaluating plant-based food supplements for gastrointestinal disorders similarly found that while licorice is among the most frequently used botanical ingredients in digestive health products across European markets, the majority of health claims for herbal GI supplements lack robust clinical substantiation and are largely based on traditional use evidence rather than high-quality controlled trials.
A Note on Peptic Ulcer Claims
Older literature sometimes cited DGL as a treatment for peptic ulcers. However, a double-blind, randomized, cross-over clinical trial by Engqvist et al. (1973) published in Gut found no demonstrable healing effect of deglycyrrhizinated licorice extract (Caved-S) on gastric ulcer compared to placebo. Given this conflicting older evidence and the absence of recent high-quality trials specifically on DGL and peptic ulcer healing, claims that DGL reliably heals peptic ulcers should be approached with caution and are not established by current evidence.
Summary of Potential Benefits
Based on available peer-reviewed evidence, DGL may offer the following benefits as a complementary (not replacement) approach to managing reflux symptoms:
- Reduction in subjective heartburn and regurgitation symptoms in individuals with GER, as demonstrated in a 2025 Phase III RCT
- Improved quality of life measures related to GERD symptoms over a 28-day treatment period
- A comparatively favorable safety profile relative to whole licorice extract, due to the removal of most glycyrrhizin
Importantly, DGL has not been proven to cure GERD, to replace acid-suppressing medications, or to heal peptic ulcers based on current controlled trial evidence.
How to Use DGL Supplements
DGL licorice is commercially available in several forms, including chewable tablets, lozenges, powders, and capsules. Chewable forms are commonly recommended because chewing is thought to stimulate saliva production, which may itself provide a degree of acid buffering.
Typical usage guidance found on product labels suggests taking DGL 20 to 30 minutes before meals. However, specific dosing, formulation strength, and frequency vary significantly between products. The trial dose used in the Raj et al. (2025) study involved a standardized proprietary extract that may differ substantially from over-the-counter DGL products.
Always follow the instructions on product labeling or, preferably, seek guidance from a qualified healthcare provider about appropriate use for your individual situation.
Safety, Side Effects, and Precautions
DGL vs. Whole Licorice
Because DGL has most of its glycyrrhizin removed, it carries a substantially lower risk of the mineralocorticoid-like side effects associated with whole licorice, including sodium retention, potassium loss, elevated blood pressure, and edema. These risks from whole licorice were clearly documented in a systematic review and meta-analysis by Penninkilampi et al. published in the Journal of Human Hypertension. Nevertheless, “deglycyrrhizinated” does not mean glycyrrhizin-free; trace amounts may remain, and individuals with pre-existing cardiovascular conditions, hypertension, kidney disease, or low potassium levels should consult a physician before use.
Pregnancy and Breastfeeding
Licorice consumption during pregnancy carries specific concerns. According to PubMed, glycyrrhizin inhibits placental 11β-hydroxysteroid dehydrogenase type 2, an enzyme that normally protects the fetus from excess maternal cortisol. A 2013 prospective cohort study (Choi et al.) published in Planta Medica found a marginally elevated rate of stillbirths among women who took licorice-containing formulations during pregnancy, though the authors acknowledged limitations and called for larger studies. Women who are pregnant or breastfeeding should avoid DGL supplements unless specifically advised otherwise by their healthcare provider.
Drug Interactions
Individuals taking medications that affect potassium levels (such as diuretics, corticosteroids, or cardiac glycosides) or antihypertensives should seek medical guidance before adding DGL to their regimen. Although DGL is sometimes used alongside conventional reflux medications, there is insufficient high-quality data on interactions between DGL and PPIs or H2-receptor antagonists to make broad recommendations. Discuss any combination with a qualified healthcare provider.
When to See a Doctor
DGL is intended as a complementary approach and should not delay or replace appropriate medical evaluation. Seek prompt medical attention if you experience any of the following:
- Acid reflux or heartburn symptoms that persist or worsen despite self-care measures
- Difficulty or pain when swallowing
- Unintentional weight loss
- Vomiting blood or passing dark/tarry stools
- Severe or persistent chest pain
- Symptoms that have been present for several weeks without improvement
A healthcare professional can perform appropriate diagnostic evaluation, including endoscopy if indicated, and advise on a safe and effective treatment plan tailored to your needs.
Summary
Deglycyrrhizinated licorice (DGL) is a processed form of licorice root extract with significantly reduced glycyrrhizin content, lowering the cardiovascular risks associated with whole licorice. Peer-reviewed clinical evidence, most notably a 2025 Phase III randomized controlled trial, supports its potential to reduce heartburn and regurgitation symptoms in individuals with gastroesophageal reflux when used as a complementary approach alongside appropriate medical care.
Its mechanism is not acid suppression but rather proposed mucosal support, though the specific mechanisms remain an active area of research. Claims about DGL reliably healing peptic ulcers are not supported by consistent controlled trial evidence.
DGL is generally well-tolerated by most adults, but those who are pregnant, breastfeeding, hypertensive, have kidney disease, or are taking medications affecting potassium or blood pressure should consult a clinician before use.
