Licorice root: medicinal properties, applications, beverages – safety considerations during pregnancy

The dried rhizome of licorice (Glycyrrhiza glabra) represents a cornerstone of classical phytotherapy. Its primary bioactive constituent is glycyrrhizin (glycyrrhizic acid)—a triterpenoid saponin approximately 50 times sweeter than sucrose.

Complementing glycyrrhizin are potent prenylated flavonoids (liquiritin, isoliquiritigenin, and glabridin) conferring distinct antimicrobial defense against Helicobacter pylori, smooth-muscle antispasmodic relief, and broad antioxidant capacity.

Licorice exerts versatile pharmacological actions across organ systems:

• Gastroduodenal Cytoprotection: Enhances protective mucin synthesis, prolongs epithelial cell lifespan, and accelerates peptic ulcer and erosive gastritis resolution.
• Respiratory Secretolytic and Expectorant Efficacy: Saponins reduce bronchial mucus viscosity and stimulate ciliary clearance, relieving dry, non-productive cough.
• Anti-inflammatory and Antiviral Properties: Suppresses cyclooxygenase-2 (COX-2) activity and limits viral transcription cycles.

Glycyrrhetinic acid, the active metabolite of glycyrrhizin, potently inhibits renal 11-beta-hydroxysteroid dehydrogenase type 2 (11-beta-HSD2). Under normal physiology, 11-beta-HSD2 converts active cortisol into inactive cortisone.

Inhibition allows excessive cortisol to inappropriately saturate mineralocorticoid receptors, precipitating apparent mineralocorticoid excess (pseudohyperaldosteronism): renal sodium and water retention, severe hypokalemia, cardiac arrhythmias, and acute hypertension. Continuous therapy must not exceed 4–6 weeks, and hypertensive patients should utilize deglycyrrhizinated licorice (DGL).

Glycyrrhizin-containing licorice is strictly contraindicated throughout pregnancy. Clinical cohorts demonstrate that glycyrrhizin compromises the placental barrier, precipitating preterm labor, fetal neuroendocrine disruption, and cognitive deficits (lower IQ, behavioral dysregulation) in offspring.

Furthermore, licorice dangerously potentiates loop and thiazide diuretics (aggravating hypokalemia), amplifies digoxin toxicity, and disrupts oral anticoagulants and antihypertensive drugs.