Pleurisy root (Asclepias tuberosa) has a long history of use in North American herbal traditions, particularly among Native American groups and early European settlers. Its primary historical application was as a remedy for respiratory conditions, including pleurisy (inflammation of the lining around the lungs), coughs, and bronchitis. Traditional herbalists valued pleurisy root for its purported expectorant, diaphoretic (sweat-inducing), and anti-inflammatory properties, which were believed to help clear mucus from the lungs and soothe irritated mucous membranes.

Despite its longstanding use, there is little modern scientific evidence to support these claims. Most contemporary herbal references list pleurisy root as a traditional remedy for supporting mucus membrane health and managing respiratory issues, but there are few, if any, well-controlled clinical trials confirming its efficacy. Some phytochemical analyses have identified compounds such as flavonoids and glycosides in pleurisy root, which may have mild anti-inflammatory or expectorant effects, but the clinical relevance of these findings remains unclear.

Overall, pleurisy root's use to support mucus membranes is justified primarily by tradition rather than robust scientific validation. Its inclusion in herbal formulas for respiratory support reflects historical practices rather than evidence-based medicine.