Red yeast rice is a yeast product that is grown on rice, most commonly produced by fermenting the yeast on uncooked whole rice kernels. Red yeast rice is a food staple in China, Japan and in Asian communities in the United States and Canada. It contains substances called monacolins, thought to lower blood lipids, both cholesterol and triglycerides. Red yeast rice has been used in China since the Tang Dynasty, around 800 A.D. It is discussed in an ancient Chinese medicinal text titled "Ben Cao Gang Mu-Dan Shi Bu Yi," published during the Ming Dynasty, as a medication for indigestion, diarrhea, circulation and for the promotion of spleen and stomach health. There are three forms of red yeast rice: Zjhitai, Cholestin and Xuezhikang. Zhitai is fermented whole grain rice, but contains very little yeast. Cholestin is fermented rice with high levels of monacolin K, the monacolin responsible for lowering cholesterol. Cholestin is the form of red yeast rice found in cholesterol lowering medications sold over the counter. Xuezhikang is rice and yeast mixed with alcohol and processed to remove the gluten. Xuezhikang is 40 percent more likely to reduce cholesterol then Cholestin.