A shrub native to China and India. The stems and roots are used in traditional medicine as a diuretic and for asthma, bronchitis, and cough. It has also been promoted as a decongestant, a weight loss aid, and as a supplement to increase energy. Ma huang may cause high blood pressure, increased heart rate, or death if used with certain drugs, and may reduce the effects of certain drugs used to treat cancer and other diseases. The U.S. Food and Drug Administration has banned the sale of dietary supplements that contain ma huang. The scientific name is Ephedra sinica. Also called ephedra.