The American Journal of Cardiology recently published a reported titled “Lipid-Lowering Efficacy of Red Yeast Rice in a Population Intolerant to Statins.” The investigators reported that 25 patients with known histories of intolerance to statin drugs, when treated with red yeast rice, averaged a 21% decrease in low-density lipoprotein cholesterol, with few side effects. In this uncontrolled study, patients were allowed to purchase their own choices of red yeast rice products, and their selections were not reported. The “Discussion” section ends with the recommendation “Producing red yeast rice under controlled conditions could provide a widely available and safe dietary supplement for lowering cholesterol.”

Although the investigators acknowledged that the manufacturing process for red yeast rice in dietary supplements in not standardized, the full extent of the problem was not recognized. A comparative analysis of 10 commercial red yeast rice products reported a >30-fold range in total monacolin content. Furthermore, compared with the full spectrum of monacolins expected in a red yeast rice dietary supplement, with monacolin K representing 55% to 60%, 4 of the 10 products were >90% monacolin K, suggesting that they were actually food-grade red yeast rice “spiked” with lovastatin, the prescription statin that is chemically identical to monacolin K. An earlier report analyzed 9 commercial samples, finding a range of total monacolin content from 0% to 0.58%, with only 1 in 9 having the expected full spectrum of monacolins.

Red yeast rice dietary supplements that do contain cholesterol-lowering amounts of monacolin K are illegal. In 2007, the United States Food and Drug Administration issued warning letters to 2 companies marketing and selling red yeast rice dietary supplements. Federal law specifically excludes from the dietary supplement definition articles that are approved as new drugs. Because Mevacor (lovastatin; Merck & Company, Inc., Whitehouse Station, New Jersey) was approved as a new drug on August 31, 1987, which was before any attempts to market and sell red yeast rice dietary supplements with lovastatin content, such products are excluded from the dietary supplement definition.

Some of the dozens of red yeast rice dietary supplement products currently for sale in the United States contain monacolins. These are illegal. Others do not contain monacolins. These are legal, because they do not contain a drug, but they are not effective. Consumers cannot distinguish one from the other, as most make no label claims for monacolin content, and in fact, many make no claim for cholesterol lowering activity either. All that is claimed is red yeast rice content. As a final point, these dietary supplements cost more per month than prescription generic statin drugs.