 Biyan Pian is most often used to treat acute and chronic sinusitis and allergic rhinitis.The ingredients of Biyan Pian vary from manufacturer to manufacturer, although most products are based on Cang Er Zi San (cang er zi - Xanthium fruit, xin yi hua - Magnolia flower, bai zhi - Angelica dahurica root, and bo he - Chinese mint leaf and stem) and contain two or more ingredients from this formula.These four herbs "release the exterior", decongest the head, dry phlegm, and alleviate headache.