China Green Dieter Brand is a tea recipe blended with all natural premium grade herbs. The formula and preparation method are based on an old Chinese book of medicine, "Detailed Outlines on Chinese Herbs", by Lee Se-Zhen, 1518-1593. After centuries of use, it has proven to be one of the best healthy beverages for dieters. As our customers testify, these teas do not cause cramping. As with all natural laxatives, you should combine taking these teas with the healthy addition of fresh fruits and vegetables and natural forms of fiber for good health.