Red Yeast Rice and Grapefruit
For people who are taking red yeast rice and enjoy grapefruit or grapefruit juice they should be very careful. Grapefruit can enhance the effects of statin and can enhance blood concentration of HMG-CoA reductase inhibitors by as much as 15 times, and this can drastically increase 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.
You should take the time to discuss with your doctor is the use of grapefruit products with red yeast rice. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.