100% Natural. Cardiotonic, for normal blood pressure. Blood Pressure Herb Tea. With an excellent natural flavor, this herb tea is made of wild apocynum venetum grown in a pollution-free area in northeast China with a few other precious herbs. Apocynum contains rutin, glutamic acid, alanine, anthraquinone, etc., and is cardiotonic, diuretic and heat-clearing. It is used in Chinese medicine as a principal herb to maintain normal blood pressure and to strengthen the heart.