Glycyrrhizic acid, a major active compound found in licorice root (Glycyrrhiza glabra), has been traditionally used in various systems of medicine, including Traditional Chinese Medicine (TCM) and Ayurveda, to support respiratory health. In TCM, licorice is a common component in herbal formulas for coughs, sore throat, and bronchitis, attributed to its soothing and anti-inflammatory properties. The historical use of glycyrrhizic acid-containing preparations for bronchial support is well-documented, with references spanning centuries.

Regarding scientific validation, some studies have investigated the biological activities of glycyrrhizic acid. It has demonstrated anti-inflammatory and antiviral effects in vitro and in animal models, which could theoretically benefit the respiratory system. However, direct clinical evidence supporting glycyrrhizic acid for bronchial or respiratory conditions in humans is limited and not conclusive. Most research focuses on broader health effects or other indications (such as liver health or viral infections), and robust, high-quality clinical trials specifically addressing bronchial health are lacking.

Thus, while traditional use is strong and some preliminary scientific rationale exists, the current evidence supporting glycyrrhizic acid specifically for the bronchial system is modest, justifying a rating of 2 out of 5.