Red yeast rice should not be taken with cholesterol-lowering (statin) medications unless supervised by your doctor, because the supplement may enhance their effect, therefore increasing the risk of liver damage. If you are already taking a statin, talk to your health care provider before adding red yeast rice to your regimen.
Grapefruit and grapefruit juice can enhance the effects of statins and significantly increase their blood levels, increasing the risk of side effects and liver damage. Because red yeast rice may act similarly in the body to statins, you should avoid drinking grapefruit juice or eating grapefruit or marmalade while taking red yeast rice.
Statins may deplete the coenzyme called CoQ10 from the body. CoQ10 is very important in heart and muscle health and in energy production. Side effects of CoQ10 depletion include fatigue, muscle aches and pains, and muscle damage. Red yeast rice also may deplete CoQ10 from the body. It is important to supplement your diet with CoQ10, 150 - 200 mg at night, while you are taking red yeast rice products, and for 4 weeks after you stop taking red yeast rice.