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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Red yeast rice unregulated, little studied

Anthony L. Komaroff

DEAR DOCTOR K: My last two blood tests showed that my cholesterol is too high. My doctor wants me to take a statin drug, but I’d rather use a natural remedy. I saw an ad for red yeast rice that says it’s as effective as statins. What do you think?


Many of my patients think that if God put a chemical in our environment, it must be safe. But if clever humans put it there – maybe it’s dangerous. Maybe we’re not as clever as we think.

It surely is true that most of the “unnatural” drugs created by humans can have side effects along with their benefits. But it also is true that many “natural” chemicals in our environment – such as arsenic – can be toxic.

Red yeast rice is an example of a natural treatment that can have benefits … and risks. It is formed by a chemical reaction between rice and a particular type of yeast. The reaction produces a family of chemicals called monacolins, which lower cholesterol by inhibiting the liver enzyme HMG-CoA reductase. That’s exactly what the cholesterol medicines, statins, do.

Because red yeast rice is sold as a dietary supplement, the FDA does not regulate how it is manufactured. No one besides the manufacturer is assuring that it is free of dangerous impurities that could lead to serious health problems. In addition, the monacolin content can vary from brand to brand and batch to batch of red yeast rice. So, unlike a statin pill, you may be underdosing or overdosing – and you won’t know which. Either could adversely affect your health.

Maybe more important, there are few scientific studies of the possible benefits and side effects of red yeast rice. Statins have been carefully studied in hundreds of thousands of people over many years. We have solid scientific evidence of their benefit, and a solid idea of how often they produce side effects. We just don’t have any such evidence with red yeast rice.

Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.