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Licorice root

Licorice products containing glycyrrhizin raised blood pressure in two meta-analyses, by about 3 to 5 mm Hg systolic, and lowered potassium, renin and aldosterone. Effects appeared at 100 mg of glycyrrhizin a day. Liver disease trials reported lower liver enzymes. Small trials of a deglycyrrhizinated extract reported fewer indigestion and reflux symptoms.

Add to Bio HackChecked 2026-11-09
Status
Dietary supplement and food flavoring in the US. Not FDA-approved for any condition.
Also called
licorice, liquorice, Glycyrrhiza glabra, Glycyrrhiza uralensis, glycyrrhizin, glycyrrhizic acid, glycyrrhetinic acid, DGL, deglycyrrhizinated licorice, GutGard
Taken for
liver health, hepatitis, digestion, indigestion, heartburn, acid reflux, stomach ulcers, adrenal fatigue

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help3

Reported risks2

What people take it for, and what was found

Shown to help3

Moderate

Liver enzymes in liver disease

Shown to lower the liver enzymes ALT by about 16 U/L and AST by about 7 U/L in adults with liver disease.

The numbers and sources
Effect
Across 15 trials (1,367 participants), licorice preparations lowered ALT by 15.63 U/L (95% CI -25.08 to -6.18) and AST by 7.37 U/L (95% CI -13.13 to -1.61) against controls. GGT and total bilirubin did not change significantly overall. Purified glycyrrhizic acid compounds showed larger reductions [1].
Population
Adults with primary liver disease, in trials of placebo or standard care [1].
Sources
[1]
Caveats
Preparations, durations and settings varied widely, some combined licorice with other herbs, and the authors note heterogeneity and possible language bias [1]. Liver enzymes are not outcomes such as cirrhosis or death.
Limited

Indigestion

One trial found a deglycyrrhizinated extract lowered indigestion symptom scores more than placebo over 30 days in 50 adults.

The numbers and sources
Effect
On a deglycyrrhizinated extract (GutGard), total symptom scores and the Nepean dyspepsia index fell more than on placebo at days 15 and 30 (p ≤ 0.05) [2]. A Cochrane review pooled this trial as SMD -1.86 (95% CI -2.54 to -1.19), moderate certainty [3].
Population
50 adults with functional dyspepsia, 75 mg twice a day for 30 days [2].
Sources
[2], [3]
Caveats
One small trial of one branded extract [3].
Limited

Heartburn and acid reflux

One trial found a branded extract improved reflux quality of life and cleared heartburn and regurgitation sooner than placebo over 28 days.

The numbers and sources
Effect
Over 28 days, reflux-related quality of life was better on GutGard than placebo (p 0.014), and heartburn (p 0.005 at day 28) and regurgitation (p 0.022 at day 28) resolved earlier [4].
Population
200 adults with reflux symptoms at one center [4].
Sources
[4]
Caveats
One trial of one branded extract, standardized to 3% glycyrrhizin or less [4].

Not shown to help1

Limited

Stomach ulcers

Small trials found deglycyrrhizinated licorice healed stomach and duodenal ulcers no better than placebo. Added to antibiotics, licorice raised H. pylori clearance in one trial.

Compared with placebo [9][10][11]; cimetidine [12]; clarithromycin-based triple therapy alone [13]

The numbers and sources
Effect
In 96 people with gastric ulcer, healing after 4 weeks did not differ between deglycyrrhizinated licorice and placebo, by gastroscopy, radiology, ulcer area or symptoms [9]. A crossover trial of 760 mg three times a day for 4 weeks in 38 people found no faster healing than placebo [10]. In 47 people with duodenal ulcer, a month of deglycyrrhizinated licorice showed no advantage over placebo [11]. Against cimetidine in 100 people with gastric ulcer, healing did not differ, about 63% at 6 weeks and 91% at 12 weeks [12]. Added to clarithromycin-based triple therapy for 2 weeks, licorice cleared H. pylori in 83.3% against 62.5% on triple therapy alone [13].
Population
96 [9], 38 [10] and 100 [12] adults with gastric ulcer. 47 adults with duodenal ulcer [11]. 120 adults with H. pylori and dyspepsia, 30% with peptic ulcer [13].
Sources
[9], [10], [11], [12], [13]
Caveats
The ulcer healing trials are small and were published from 1971 to 1982. The cimetidine comparison was single-blind with no placebo group [12]. The H. pylori trial measured clearance of the infection, not ulcer healing, and the abstract does not describe blinding [13].

Claimed, not studied in people1

Untested

Adrenal fatigue

Not studied in people for adrenal fatigue. Licorice slows the body's inactivation of cortisol, and a systematic review found no evidence adrenal fatigue is a medical condition.

No study in people. This rests on how it acts in the body.

The numbers and sources
Effect
In 7 healthy volunteers given licorice, sodium retention came with a change in cortisol metabolism showing that licorice blocks 11-beta-hydroxysteroid dehydrogenase, the enzyme that converts cortisol to inactive cortisone in the kidney [14]. A systematic review of 58 studies of cortisol and fatigue found no substantiation that adrenal fatigue is an actual medical condition [15].
Population
7 healthy volunteers in a mechanism study [14]. 58 studies of cortisol and fatigue [15].
Sources
[14], [15]
Caveats
The enzyme effect is what raises blood pressure and lowers potassium (see Risks), and it does not show that licorice changes fatigue. No trial of licorice for fatigue or adrenal symptoms was located.

Doses studied

Blood pressure studies used products with at least 100 mg of glycyrrhizic acid a day [5][6]. The indigestion trial used 75 mg of a deglycyrrhizinated extract twice a day for 30 days [2], and the reflux trial gave the same extract for 28 days [4].

Risks

Reported risks2

Strong

Raised blood pressure

Shown to raise systolic blood pressure about 3 to 5 mmHg with glycyrrhizic acid, rising with daily dose. Products based on licorice flavonoids did not.

The numbers and sources
Effect
In 18 studies (337 people) of at least 100 mg glycyrrhizic acid a day, systolic pressure rose 5.45 mm Hg (95% CI 3.51 to 7.39) and diastolic 3.19 mm Hg (95% CI 0.10 to 6.29), and the rise tracked the daily dose [5]. In 8 RCTs (541 participants), glycyrrhizic acid products raised systolic pressure 3.48 mm Hg (95% CI 2.74 to 4.21) and diastolic 1.27 mm Hg (95% CI 0.76 to 1.78). Products based on licorice flavonoids did not change blood pressure significantly [7]. In a crossover trial, 100 mg glycyrrhizic acid a day for 2 weeks raised home systolic pressure 3.1 mm Hg (95% CI 0.8 to 5.4), against -0.3 mm Hg on the control product [6].
Population
Adults in controlled studies [5][7]. 28 healthy volunteers, median age 24 [6].
Sources
[5], [7], [6]
Caveats
The crossover trial was not blinded [6]. Deglycyrrhizinated products contain little glycyrrhizin and were not the subject of these analyses.
Moderate

Low potassium and pseudo-aldosteronism

Shown to lower blood potassium, renin and aldosterone. Case reports describe pseudo-aldosteronism with muscle breakdown after licorice herbal medicines or foods.

The numbers and sources
Effect
Plasma potassium fell 0.33 mmol/L, plasma renin activity fell 0.82 ng/mL per hour (95% CI -1.27 to -0.37) and aldosterone fell 173.24 pmol/L (95% CI -231.65 to -114.83) [5]. At 100 mg glycyrrhizic acid a day, renin fell 30.0% and aldosterone 45.1% [6]. A case review of pseudo-aldosteronism with muscle breakdown (rhabdomyolysis) found most Japanese cases in older women with high blood pressure taking herbal medicines containing licorice, and most cases elsewhere in younger men eating licorice foods. The reported case, a 79-year-old woman, developed it after 2 weeks of two herbal medicines containing 5 g of licorice in total [8].
Population
337 people in controlled studies [5]. 28 healthy volunteers [6]. Published case reports [8].
Sources
[5], [6], [8]
Caveats
Case reports cannot give a rate [8].

Sources

  1. Giangrandi I, Dinu M, Napoletano A, et al. Licorice and liver function in patients with primary liver disease: A systematic review and meta-analysis of RCTs. Phytotherapy Research. 2024. https://doi.org/10.1002/ptr.8288
  2. 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. Evidence-Based Complementary and Alternative Medicine. 2012. https://doi.org/10.1155/2012/216970
  3. Báez G, Vargas C, Arancibia M, et al. Non-Chinese herbal medicines for functional dyspepsia. Cochrane Database of Systematic Reviews. 2023. https://doi.org/10.1002/14651858.CD013323.pub2
  4. 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. Complementary Medicine Research. 2025. https://doi.org/10.1159/000543367
  5. Penninkilampi R, Eslick EM, Eslick GD. The association between consistent licorice ingestion, hypertension and hypokalaemia: a systematic review and meta-analysis. Journal of Human Hypertension. 2017. https://doi.org/10.1038/jhh.2017.45
  6. af 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. The American Journal of Clinical Nutrition. 2024. https://doi.org/10.1016/j.ajcnut.2024.01.011
  7. Wu T, Yang J, Xia J, Sun G. Effects of Licorice Functional Components Intakes on Blood Pressure: A Systematic Review with Meta-Analysis and NETWORK Toxicology. Nutrients. 2024. https://doi.org/10.3390/nu16213768
  8. Yoshino T, Yanagawa T, Watanabe K. Risk factors for pseudoaldosteronism with rhabdomyolysis caused by consumption of drugs containing licorice and differences between incidence of these conditions in Japan and other countries: case report and literature review. Journal of Alternative and Complementary Medicine. 2014. https://doi.org/10.1089/acm.2013.0454
  9. Bardhan KD, Cumberland DC, Dixon RA, Holdsworth CD. Clinical trial of deglycyrrhizinised liquorice in gastric ulcer. Gut. 1978. https://doi.org/10.1136/gut.19.9.779
  10. Engqvist A, von Feilitzen F, Pyk E, Reichard H. Double-blind trial of deglycyrrhizinated liquorice in gastric ulcer. Gut. 1973. https://doi.org/10.1136/gut.14.9.711
  11. Feldman H, Gilat T. A trial of deglycyrrhizinated liquorice in the treatment of duodenal ulcer. Gut. 1971. https://doi.org/10.1136/gut.12.6.449
  12. Morgan AG, McAdam WA, Pacsoo C, Darnborough A. Comparison between cimetidine and Caved-S in the treatment of gastric ulceration, and subsequent maintenance therapy. Gut. 1982. https://doi.org/10.1136/gut.23.6.545
  13. Hajiaghamohammadi AA, Zargar A, Oveisi S, et al. To evaluate of the effect of adding licorice to the standard treatment regimen of Helicobacter pylori. Brazilian Journal of Infectious Diseases. 2016. https://doi.org/10.1016/j.bjid.2016.07.015
  14. Stewart PM, Wallace AM, Valentino R, et al. Mineralocorticoid activity of liquorice: 11-beta-hydroxysteroid dehydrogenase deficiency comes of age. Lancet. 1987. https://doi.org/10.1016/s0140-6736(87)91014-2
  15. Cadegiani FA, Kater CE. Adrenal fatigue does not exist: a systematic review. BMC Endocrine Disorders. 2016. https://doi.org/10.1186/s12902-016-0128-4

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