Licorice Root/Gān Cǎo 甘草

A 2019 meta-analysis pooled five randomized trials with 609 adults undergoing surgery with a breathing tube. Gargling or applying licorice beforehand was associated with roughly half the incidence of postoperative sore throat and lower severity, with no significant adverse events reported. The authors concluded licorice appears more effective than no treatment, consistent with its traditional throat-soothing use.

In a randomized, double-blind trial, 66 overweight women with PCOS took 1.5 g/day licorice extract or placebo alongside a low-calorie diet for 8 weeks. Research suggests the licorice group saw greater improvements in body weight, BMI, fasting glucose, insulin resistance and lipid profile than diet alone. The authors noted limitations and called for further confirmation.

A 2024 review summarized the traditional uses and bioactive constituents of Glycyrrhiza uralensis, particularly its saponins (glycyrrhizin) and flavonoids. It noted laboratory and animal research into liver-protective, antibacterial, antioxidant, anti-diabetic, anti-inflammatory, cardiovascular and muscle-supporting effects, while also reviewing the herb's toxicity profile and urging further clinical studies before firm claims are made.

A 2023 review analysed 104 published case reports of complications from excessive licorice intake. Continuous consumption of large amounts can mimic excess aldosterone, causing high blood pressure and low potassium; in rare cases this led to arrhythmias, muscle weakness or hospitalization. The authors concluded that moderate intake is the key safety message for consumers and regulators.