Licorice root (Glycyrrhiza glabra) has a long history of use in traditional herbal medicine for respiratory ailments, including pleurisy—a condition characterized by inflammation of the pleura (the membranes surrounding the lungs). In Traditional Chinese Medicine (TCM) and various European herbal traditions, licorice root is valued for its demulcent (soothing), anti-inflammatory, and expectorant properties. These qualities were thought to help soothe irritated lung tissue, reduce coughing, and ease discomfort associated with pleuritic pain.

The rationale for using licorice root in pleurisy is primarily based on its historical use and the presence of certain bioactive compounds, such as glycyrrhizin, which has demonstrated anti-inflammatory and immunomodulatory effects in laboratory studies. However, while licorice root has been studied for its general effects on inflammation and respiratory health, there is little direct scientific evidence specifically examining its efficacy in treating pleurisy in humans. Most modern research focuses on its use in broader respiratory conditions like bronchitis or cough.

In summary, the use of licorice root for pleurisy is justified mainly by traditional use rather than robust clinical evidence. While its anti-inflammatory properties provide a plausible mechanism, its direct effectiveness for pleurisy remains insufficiently supported by clinical trials. Individuals should use caution and consult healthcare providers before using licorice root, as it can cause significant side effects and interactions, especially with long-term use.