One reference work states: “To take enough willow bark to achieve the benefits aspirin provides or to take enough foxglove to achieve the full lifesaving effects of digitalis is much more easily accomplished via a pill than by eating natural substances. ”
वनस्पतींमधील औषधी घटक वेगळे केल्यावर त्यांचा योग्य आणि अचूक प्रमाणात वापर करता येतो.