Support healthy respiratory function with Pleurisy root liquid extract from Herb Pharm. We prepare our Pleurisy Root Extract from the roots of Asclepias tuberosa plants which are Certified Organically Grown on our own farm or are Sustainably Wildcrafted in their wild native habitat. To assure optimal extraction of Pleurisy Root's bioactive compounds, the roots are hand-dug only in autumn or spring, are carefully shade-dried, and are then thoroughly extracted. Caution: Seek expert medical advice before taking during pregnancy.