The fruit of Citrus aurantium has been used as a medicinal herb in China for decades. This has led some nutritionist to try the medical benefits of the bitter orange to help control weight gain. Citrus aurantium is commonly referred to as bitter orange. Zhi shi is the immature dried fruit of citrus aurantium. Zhi shi has bee used in Traditional Chinese Medicine to treat chest congestion and stimulate gastrointestinal functions. In recent years this supplement has been promoted for appetite control.