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Red Yeast Rice

What Should I Know About It?


Updated May 16, 2014

Red Yeast Rice
Kristin Duvall Collection/The Image Bank/Getty Images

What is Red Yeast Rice?

Red yeast rice is a substance made by fermenting a type of red yeast called Monascus purpureus over rice.

Red yeast rice has been used in China as a preservative, spice, and food coloring. It's used to give Peking duck its characteristic red color and can also be an ingredient in fish sauce, fish paste, and rice wine. Red yeast rice is used in traditional Chinese medicine as a remedy for poor circulation, indigestion, and diarrhea.

Red yeast rice contains naturally-occurring substances called monacolins. Monocolins, particularly one called lovastatin, is believed to be converted in the body to a substance that inhibits HMG-CoA reductase, an enzyme that triggers cholesterol production. This is the way the popular statin drugs work.

Because of this action, red yeast rice products containing a higher concentration of monocolins have been developed and marketed as a natural product to lower cholesterol.

Related: Natural Remedies for High Cholesterol.

The problem is that the primary ingredient in these supplements, lovastatin, is also the active pharmaceutical ingredient in prescription drugs for high cholesterol such as Mevacor. In fact, lovastatin was originally derived from another type of red yeast called Monascus ruber.

When the FDA discovered that red yeast rice contained a substance found in prescription drugs, it banned red yeast rice products containing lovastatin. In August, 2007, the FDA issued a warning that several red yeast rice products still contained lovastatin. The manufacturers of these products have since recalled these products.


Red yeast rice is classified as a dietary supplement by the FDA. Because of its similarity to the statin drugs, there is an ongoing legal debate about whether red yeast rice should be reclassified as a prescription drug rather than a dietary supplement.

Why People Use Red Yeast Rice

  • To Lower Cholesterol and Triglycerides
  • Since red yeast rice products can no longer contain lovastatin, it's unclear whether red yeast products currently on the market would have any effect on cholesterol levels.

    What is the Evidence for Red Yeast Rice?

    There have only been a few well-designed studies on red yeast rice in humans.

    For example, a study conducted by the UCLA School of Medicine examined the use of red yeast rice in 83 people with high cholesterol.

    Subjects were randomized to receive 2.4 grams a day red yeast rice or placebo, and they were told to consume a 30% fat diet (with no more than 10% of this from saturated fat and less than 300 mg cholesterol a day).

    After the 12 week treatment period, there was a significant reduction in total cholesterol, LDL cholesterol, and triglyceride levels, compared with placebo. HDL cholesterol was not affected in this study.

    Side Effects

    Information about red yeast rice side effects.


    Red yeast rice products have been found to contain citrinin, a toxic by-product of the fermentation process.

    Pregnant or nursing women and children should not use red yeast rice.

    People with liver disease or at risk for liver disease should not use red yeast rice, as red yeast rice may impair liver function.

    People with acute infections, kidney disease, or who have had an organ transplant should not use red yeast rice.

    People taking red yeast rice who develop muscle pain or tenderness should discontinue the product immediately and check with their doctor.

    Potential Drug Interactions

    See a list of drugs that may interact with red yeast rice.


    Baens-Arcega L, Ardisher AG, Beddows CG, et al. Indigenous amino acid/peptide sauces and pastes with meat-like flavors. Chinese soy sauce, Japanese shoyu, Japanese miso, Southeast Asian fish sauces and pastes, and related fermented foods. In: Steinkraus KH, ed. Handbook of Indigenous Fermented Foods. 2nd ed. New York, NY: Marcel Dekker, Inc; 1996:625-633.

    Endo A. Monacolin K. A new hypocholesterolemic agent produced by a Monascus species. J Antibiot (Tokyo). 1979; 32:852-854.

    Heber D, Yip I, Ashley JM, Elashoff DA, Elashoff RM, Go VL. Cholesterol-lowering effects of a proprietary Chinese red-yeast-rice dietary supplement. American Journal of Clinical Nutrition. 69.2 (1999):231-6.

    Monograph. Monascus purpureus (red yeast rice). Alternative Medicine Review. 9.2 (2004):208-10.

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