People who take red yeast rice pills to lower their cholesterol levels may not be getting their expected protection against suffering a heart attack. North Americans spend an estimated 40 million dollars a year on these pills. Harvard professor Pieter Cohen tested 28 brands of red yeast rice supplements purchased at major U.S. retail chains, such as GNCs and Walgreens, for levels of the active ingredient monacolin K, which is identical to the prescription statin cholesterol-lowering drug, lovastatin (European Journal of Preventive Cardiology, June 23, 2017). He found that:
• Two of the 28 brands had no detectable levels of monacolin K.
• The other 26 brands had monacolin K levels that varied from 0.09 to 5.48 mg per 1,200 mg of red yeast rice. This is totally unacceptable; there is a 120-fold difference from the recommended daily dose.
• Six of the brands could have serious side effects because they exceeded the 4mg/day limit recommended by the Food and Drug Administration (FDA).
Red yeast rice is made by fermenting rice with a red-colored fungus, which produces the active ingredient, monacolin. Each fermentation procedure yields widely varying doses of monacolin and thus each manufacturer should be measuring the monacolin produced for each batch of pills, but we have no evidence that this is being done. Manufacturers of prescription drugs that had such variations from standard doses would be liable for federal prosecution, but manufacturers of over-the-counter red yeast rice and other supplements are almost never prosecuted.
• The labels on red yeast rice supplements do not tell you how much of the active ingredient, monacolin, is in each pill, even though many labels state how much red yeast rice is in each pill. Monacolin levels, not red yeast rice weights, determine the potency and side effect of these pills.
• Most brands of over-the-counter red yeast rice do not warn about the possible risks of taking red yeast rice pills for people who take prescription statins at the same time.
Why Supplements Are Not Regulated
In 1994, U.S. Senators Harkins and Hatch got Congress to pass a law that prevented the FDA from regulating food, which in effect prevents the FDA from regulating any dietary supplements. In 2007 the FDA introduced new manufacturing standards for dietary supplements, but this study confirms that many manufacturers still are not checking the potency of their pills as they should. In 2010, the FDA issued further manufacturing guidelines designed to "give consumers greater confidence that any dietary supplement they use has been manufactured to ensure its identity, purity, strength, and composition." However, the rate of adverse reactions to red yeast rice (muscle pain, gastrointestinal symptoms and muscle and liver damage) appears to be as common as it is for prescription statins (British Journal of Clinical Pharmacology, Jan. 19, 2017).
In 2014, the FDA sent a warning letter to a company whose red yeast rice product had 4mg of monacolin K/daily dose, a dose high enough to make it a drug that would need a prescription, and should not have been sold over-the-counter. Furthermore, some red yeast rice supplements contain a toxin called citrinin, which can damage your kidneys and cause cancer in animals (JAMA Internal Medicine, Oct 25, 2010).
• Tell your doctor if you are taking red yeast rice.
• A low-cost prescription statin might be a better choice because the government has tighter regulations on prescription medications.
• Red yeast rice is likely to remain on the market, but I believe that it can be dangerous to take such loosely-regulated supplements.