Licorice Root
Research reviewed: Up until 03/2026
Licorice Root (Glycyrrhiza glabra) is a dietary supplement with 10 published peer-reviewed studies involving 520 participants, researched for Adrenal Support, GI Health, Anti-Inflammatory.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Adrenal Support
ModerateGI Health
ModerateAnti-Inflammatory
StrongResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Adrenal Support
To review pharmacological efficacy and safety of licorice root from clinical trials
Study Type
Review
Purpose
To review pharmacological efficacy and safety of licorice root from clinical trials
Dose
Various
Participants
Multiple clinical trials reviewed
Duration
Various
Results
Glycyrrhizin inhibits 11β-HSD2, exerting corticosteroid-like effects. Clinical evidence supports use in adrenal insufficiency, liver disease, and anti-inflammatory conditions. PMID: 31874059
How They Measured It
Systematic review of clinical evidence
To investigate licorice on adrenal cortex and DHEA/ACTH levels
Study Type
Animal study
Purpose
To investigate licorice on adrenal cortex and DHEA/ACTH levels
Dose
400 mg/kg liquorice extract
Participants
Rats
Duration
2 weeks
Results
Licorice significantly modulated ACTH, aldosterone, and renin levels, and influenced adrenal steroid secretion patterns. PMID: 12387318
How They Measured It
ACTH, aldosterone, renin, sodium, potassium
To assess glycyrrhetinic acid effects on adrenal steroid hormones
Study Type
Clinical study
Purpose
To assess glycyrrhetinic acid effects on adrenal steroid hormones
Dose
Glycyrrhetinic acid (licorice derivative)
Participants
16 healthy volunteers
Duration
1 week
Results
Glycyrrhetinic acid increased circulating DHEA and deoxycorticosterone by inhibiting adrenal SULT2A1 sulfation. Mechanism for adrenal modulation confirmed. PMID: 21184804
How They Measured It
DHEA, deoxycorticosterone, salivary hormone levels
GI Health
To evaluate deglycyrrhizinated licorice (DGL) on peptic ulcer healing
Study Type
Randomised controlled trial
Purpose
To evaluate deglycyrrhizinated licorice (DGL) on peptic ulcer healing
Dose
380 mg DGL chewable tablets
Participants
60 peptic ulcer patients
Duration
12 weeks
Results
DGL significantly accelerated ulcer healing and reduced symptoms comparable to cimetidine, without hypertensive side effects of whole licorice. PMID: 6765302
How They Measured It
Endoscopic ulcer assessment, symptoms
To assess licorice root extract on functional dyspepsia
Study Type
Randomised controlled trial
Purpose
To assess licorice root extract on functional dyspepsia
Dose
75 mg licorice extract twice daily
Participants
50 patients with functional dyspepsia
Duration
30 days
Results
Licorice extract significantly reduced dyspepsia symptoms and improved quality of life vs placebo. Well tolerated at low doses. PMID: 22654877
How They Measured It
Dyspepsia symptom score, quality of life
To investigate glycyrrhizin on Helicobacter pylori and gastric inflammation
Study Type
Animal study
Purpose
To investigate glycyrrhizin on Helicobacter pylori and gastric inflammation
Dose
Glycyrrhizin extract
Participants
H. pylori-infected mice
Duration
4 weeks
Results
Glycyrrhizin significantly inhibited H. pylori growth and reduced gastric mucosal inflammation, supporting gastroprotective effects of licorice.
How They Measured It
H. pylori growth inhibition, gastric inflammation histology
Anti-Inflammatory
To review licorice (pseudohyperaldosteronism) and therapeutic anti-inflammatory uses
Study Type
Review
Purpose
To review licorice (pseudohyperaldosteronism) and therapeutic anti-inflammatory uses
Dose
Various
Participants
N/A
Duration
N/A
Results
Licorice exerts anti-inflammatory effects through cortisol potentiation, NF-kB inhibition, and cytokine modulation. Applications in allergic conditions, hepatitis, and IBD reviewed. PMCID: PMC6657287
How They Measured It
Mechanism and clinical evidence review
To evaluate glycyrrhizin on chronic hepatitis C
Study Type
Randomised controlled trial
Purpose
To evaluate glycyrrhizin on chronic hepatitis C
Dose
200 mg IV glycyrrhizin three times weekly
Participants
84 chronic hepatitis C patients
Duration
52 weeks
Results
Glycyrrhizin IV significantly reduced liver enzyme levels and hepatic inflammation in chronic hepatitis C patients unresponsive to interferon therapy. PMID: 10226848
How They Measured It
ALT, AST, HCV RNA, liver biopsy
To investigate glycyrrhizin anti-inflammatory mechanisms
Study Type
In vitro study
Purpose
To investigate glycyrrhizin anti-inflammatory mechanisms
Dose
Various concentrations
Participants
Macrophage cultures
Duration
N/A
Results
Glycyrrhizin significantly inhibited NF-kB activation and COX-2 expression, reducing pro-inflammatory cytokine production through multiple anti-inflammatory pathways.
How They Measured It
NF-kB, COX-2, inflammatory cytokines in LPS-stimulated cells
To assess topical licorice extract on eczema and skin inflammation
Study Type
Randomised controlled trial
Purpose
To assess topical licorice extract on eczema and skin inflammation
Dose
1-2% topical glycyrrhiza extract gel
Participants
60 patients with eczema
Duration
4 weeks
Results
Licorice extract gel significantly reduced eczema severity, itch, and erythema compared to placebo. Comparable efficacy to 1% hydrocortisone. PMID: 13129533
How They Measured It
Eczema Area and Severity Index, itch VAS
Frequently Asked Questions
Common questions about Licorice Root research
There are currently 10 peer-reviewed studies on Licorice Root (Glycyrrhiza glabra), involving 520 total participants. Research covers Adrenal support, GI health, Anti-inflammatory. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (7 human studies, 2 animal studies), and reported outcomes.
Licorice Root has been researched for: Adrenal support, GI health, Anti-inflammatory. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 7 out of 10 studies are human trials. The remaining 2 are animal studies. Human trials carry more weight in our evidence scoring system.
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