tuneTypical Dose
150 mg/day as 75 mg twice daily for 4 weeks in the available GutGard dyspepsia and reflux trials
Botanical
Licorice Root
Glycyrrhiza glabra
Evidence TierDWADA NOT PROHIBITED
watchEffect Window
GI symptom improvement in the GutGard trials appeared within 2 weeks and was clearer by about 4 weeks.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Licorice is not a simple digestive-support herb. Narrow GI benefit is limited to specific low-glycyrrhizin extracts, while glycyrrhizin-containing licorice can raise blood pressure and lower potassium.
Licorice is marketed for digestion, ulcers, reflux, adrenal support, and general soothing, but the human evidence does not support treating generic licorice root as a broad GI supplement. The main positive data come from proprietary low-glycyrrhizin extracts such as GutGard for functional dyspepsia and reflux-related symptoms. By contrast, glycyrrhizin-containing licorice has a well-established safety problem. It can increase blood pressure, suppress renin and aldosterone, and contribute to hypokalemia and fluid retention.
The main safety mechanism is inhibition of 11beta-hydroxysteroid dehydrogenase 2 by glycyrrhizin metabolites, which increases mineralocorticoid-like effects and can raise blood pressure while lowering potassium. Claimed GI benefits are tied more narrowly to specific low-glycyrrhizin flavonoid-rich extracts rather than to the whole root.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Possible improvement in functional dyspepsia symptoms with a specific low-glycyrrhizin extract
- Possible improvement in reflux-related symptoms with the same proprietary extract
Secondary Outcomes
- Glycyrrhizin-containing licorice can increase blood pressure
- Glycyrrhizin-containing licorice can contribute to hypokalemia and fluid retention
Safety
Contraindications and Interactions
Contraindications
- Hypertension
- Chronic kidney disease
- Heart failure or significant cardiovascular disease
- Pregnancy
- History of hypokalemia
Side effects
- Elevated blood pressure
- Hypokalemia
- Edema or fluid retention
- Headache or mild GI intolerance
Interactions
- Diuretics
- Digoxin
- Corticosteroids
- Antihypertensive therapy
Avoid if
- You have high blood pressure, edema, chronic kidney disease, heart failure, or a history of low potassium
- You are using generic licorice root for vague adrenal-support claims
- You are assuming whole licorice and low-glycyrrhizin extracts are interchangeable
Evidence
Study-level References
lr-SRC-001Randomized controlled trial
Sourceopen_in_newRaveendra 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. PMID:21747893.
Population: Adults with functional dyspepsia or non-ulcer dyspepsia meeting Rome III criteria.
Dose protocol: 75 mg twice daily after food for 30 days
Key findings: Improved functional dyspepsia symptom scores and dyspepsia-related quality of life versus placebo.
Notes: Useful GI signal, but tightly product specific and industry linked.
Paper content
This small randomized trial found that a proprietary low-glycyrrhizin licorice extract, GutGard, improved symptom scores and dyspepsia-related quality of life over 30 days in adults with functional dyspepsia. The findings are useful because they support a narrow GI claim for a specific extract, not for generic whole licorice root. The study was also industry linked, short, and built around patient-reported outcomes rather than harder clinical endpoints.
lr-SRC-002Randomized controlled trial
Sourceopen_in_newRaj 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. doi:10.1159/000543367. PMID:39929150.
Population: Adults with gastroesophageal reflux-related symptoms, especially heartburn and regurgitation.
Dose protocol: 75 mg twice daily for 28 days
Key findings: Improved reflux-related quality of life and earlier symptom resolution for heartburn and regurgitation.
Notes: Good modernization study for the same low-glycyrrhizin extract.
Paper content
This larger 2025 randomized trial extends the GutGard evidence from functional dyspepsia to reflux-related symptoms. Over 28 days, the low-glycyrrhizin extract improved GERD-related quality of life and sped up resolution of heartburn and regurgitation compared with placebo, without a clear adverse-event penalty. The trial modernizes the GI evidence base, but it still applies to one branded deglycyrrhizinated extract rather than to generic licorice root.
lr-SRC-005Randomized, double-blind, placebo-controlled trial.
Sourceopen_in_newHooshmandi H, et al. Effects of licorice extract in combination with a low-calorie diet on obesity indices, glycemic indices, and lipid profiles in overweight/obese women with polycystic ovary syndrome (PCOS). J Ovarian Res. 2024;17(1):157. doi:10.1186/s13048-024-01446-9. PMID:39080737.
Population: Overweight or obese women with polycystic ovary syndrome.
Dose protocol: 1.5 g/day licorice extract plus low-calorie diet for 8 weeks (n=66)
Key findings: Significant improvements in obesity indices, lipid profiles, fasting blood sugar, insulin, and HOMA-IR versus placebo in overweight/obese PCOS women.
Notes: Metabolic benefit in a specific clinical population. Glycyrrhizin content and blood pressure monitoring still relevant.
Paper content
This 8-week randomized, double-blind, placebo-controlled trial tested 1.5 g/day licorice extract alongside a low-calorie diet in 66 overweight or obese women with PCOS. The licorice group showed significant improvements in body weight, BMI, body fat, lipid profiles (triglycerides, total cholesterol, LDL-C, HDL-C), fasting blood sugar, insulin, and insulin resistance indices versus placebo. The study provides metabolic evidence for licorice extract in a specific clinical population. However, the glycyrrhizin content and formulation details are important for safety context, given licorice's known effects on blood pressure and electrolytes.
lr-SRC-006Randomized, double-blind, placebo-controlled trial.
Sourceopen_in_newRostamizadeh P, et al. Effects of licorice root supplementation on liver enzymes, hepatic steatosis, metabolic and oxidative stress parameters in women with nonalcoholic fatty liver disease: A randomized double-blind clinical trial. Phytother Res. 2022;36(10):3949-3956. doi:10.1002/ptr.7543. PMID:35785498.
Population: Women with nonalcoholic fatty liver disease.
Dose protocol: 1,000 mg/day licorice root extract plus weight loss diet for 12 weeks (n=60)
Key findings: Significant improvements in ALT (P<0.001), insulin (P=0.002), HOMA-IR (P=0.003), malondialdehyde (P<0.001), and liver steatosis (P<0.001) versus placebo in NAFLD women.
Notes: Extends licorice evidence into hepatic endpoints. Whole root extract, not low-glycyrrhizin formulation.
Paper content
This 12-week randomized, double-blind, placebo-controlled trial tested 1,000 mg/day licorice root extract in 60 women with nonalcoholic fatty liver disease, alongside weight loss diet and lifestyle modification in both groups. The licorice group showed significant improvements in ALT (P<0.001), insulin (P=0.002), HOMA-IR (P=0.003), malondialdehyde (P<0.001), and liver steatosis grade (P<0.001) versus placebo. This expands the evidence for licorice beyond GI symptom relief into hepatic and metabolic endpoints. The formulation was whole licorice root extract rather than a low-glycyrrhizin product, so the blood pressure and electrolyte safety considerations apply.
lr-SRC-003Systematic review and meta-analysis
Sourceopen_in_newPenninkilampi R, Eslick EM, Eslick GD. The association between consistent licorice ingestion, hypertension and hypokalaemia. A systematic review and meta-analysis. J Hum Hypertens. 2017;31(11):699-707. doi:10.1038/jhh.2017.45. PMID:28660884.
Population: Adults from clinical studies of chronic licorice ingestion containing at least 100 mg glycyrrhizic acid per day.
Dose protocol: Chronic glycyrrhizic acid exposure of at least 100 mg/day across pooled studies
Key findings: Increased blood pressure and lowered potassium, renin, and aldosterone.
Notes: Main safety anchor for glycyrrhizin-containing licorice.
Paper content
This meta-analysis is the clearest safety anchor for glycyrrhizin-containing licorice. Across 18 studies, chronic licorice ingestion increased systolic and diastolic blood pressure and lowered potassium, renin, and aldosterone. The review supports conservative safety language because the effect was seen even at modest glycyrrhizic acid exposures and is directly relevant to cardiovascular and electrolyte risk.
lr-SRC-004Randomized crossover trial
Sourceopen_in_newaf Geijerstam P, Joelsson A, Rådholm K, Nyström FH. A low dose of daily licorice intake affects renin, aldosterone, and home blood pressure in a randomized crossover trial. Am J Clin Nutr. 2024;119(3):682-691. doi:10.1016/j.ajcnut.2024.01.011. PMID:38246526.
Population: Healthy adult volunteers.
Dose protocol: 100 mg glycyrrhizic acid daily for 2 weeks
Key findings: Increased home systolic blood pressure and suppressed renin and aldosterone in healthy adults.
Notes: Useful modern confirmation that risk appears even at modest intake.
Paper content
This randomized crossover trial is a strong modernization study for licorice safety because it quantified the effects of a relatively modest glycyrrhizic acid intake under controlled conditions. Just two weeks of 100 mg glycyrrhizic acid per day increased home systolic blood pressure and suppressed renin and aldosterone in healthy adults. It reinforces that licorice toxicity is not limited to extreme intakes or obviously ill populations.