Some red yeast rice products contain substantial amounts of monacolin K, which is chemically identical to the active ingredient in the cholesterol-lowering drug lovastatin. These products may lower blood cholesterol levels and can cause the same types of side effects and drug interactions as lovastatin.
Other products contain little or no monacolin K. It is not known whether these products have any effect on blood cholesterol levels.
Consumers have no way of knowing how much monacolin K is present in most products. The labels on these products usually state only the amount of red yeast rice that they contain, not the amount of monacolin K.
The U.S. Food and Drug Administration (FDA) has determined that red yeast rice products that contain more than trace amounts of monacolin K are unapproved new drugs and cannot be sold legally as dietary supplements.
Some products contain a contaminant called citrinin, which can cause kidney failure.
Tell all your health care providers about any complementary health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
Side Effects Of Red Yeast Rice
The same types of side effects that can occur in patients taking lovastatin as a drug can also occur in patients who take red yeast rice products that contain monacolin K. Potential side effects include myopathy (muscle symptoms such as pain and weakness), rhabdomyolysis (a condition in which muscle fibers break down, releasing substances into the bloodstream that can harm the kidneys), and liver toxicity. Each of these three side effects has been reported in people who were taking it.
Supplements should not be used while pregnant or breastfeeding.
Lovastatin can interact with a variety of drugs to increase the risk of rhabdomyolysis; these drugs include other cholesterol-lowering agents, certain antibiotics, the antidepressant nefazodone, drugs used to treat fungal infections, and drugs used to treat HIV infection. Red yeast rice containing monacolin K could interact with drugs in the same way.
If the process of culturing red yeast rice is not carefully controlled, a substance called citrinin can form. Citrinin has been shown to cause kidney failure in experimental animals and genetic damage in human cells. In a 2011 analysis of products sold as dietary supplements, 4 of 11 products were found to contain this contaminant.
Consult your doctor or pharmacist.
All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.