2​ Biological Activity Theobromine(3,7-Dimethylxanthine) is a xanthine alkaloid that is used as a bronchodilator and as a vasodilator. It has a weaker diuretic activity than theophylline and is also a less powerful stimulant of smooth muscle. It has practically no stimulant effect on the central nervous system. It was formerly used as a diuretic and in the treatment of angina pectoris and hypertension. [1] 3​ References: The pharmacological and toxicological properties of this product have not been fully investigated. Exercise caution in use and handling. This product must not be used in humans.