The Medical Letter,  a highly respected source of reliable independent evaluations of drugs and therapeutics, has just published an evaluation of red yeast rice (Vol 51, Issue 1320, P 71-2, Sept 7, 2009). It has been widely promoted as a “natural” alternative to prescription medications for lowering blood LDL cholesterol levels. Studies have indeed shown that red yeast rice reduces LDL cholesterol levels and reduces the rate of major coronary events. The Medical Letter consultants concluded that it works, but they don’t recommend it. Why?

It’s Just Another Statin

When rice is fermented with the yeast Monascus purpureus, the resulting product contains numerous monacolins, which are naturally occurring HMG-CoA reductase inhibitors. One of these is identical to the prescription drug Mevacor (lovastatin). So it isn’t an alternative to prescription drugs, it’s just an alternative way of providing the same thing.

It Has Side Effects

Since red yeast rice contains statins, it can cause the same adverse effects as statin drugs, including myopathy. There have been reports of rhabdomyolysis and hepatitis. Red yeast rice contains many other components besides the active ingredients. Those other components are not necessary and may be harmful – it is quite possible that new side effects from those other components would be recognized if large numbers of patients were as carefully monitored as patients on statin drugs have been.

It May Be Contaminated with a Toxin

Some red yeast rice products contain citrinin, a mycotoxin that can cause kidney failure in animals. In one study, measurable amounts of citrinin were found in 7 out of 9 products tested. and in another study citrinin was found in four out of ten products tested, with the highest level found in a supplement sold by a major pharmacy chain.

 It’s a Less Reliable Way to Get the Benefit of Statins

Under DSHEA rules, red yeast rice products are not regulated as drugs. They are not standardized and may contain unlabelled ingredients. In one study of 9 brands, the amount of active ingredient in red yeast rice varied from 0% to 0.58% . In another study of 10 products, the content varied 100-fold. The Medical Letter says

The FDA has tried, apparently unsuccessfully, to remove red yeast rice products from the US market as unapproved formulations of an approved drug (lovastatin).

It’s More Expensive

A common argument in favor of natural medicines is that they are less expensive than Big Pharma profit-making drugs. In this case, that’s not true. According to The Medical Letter, the cost of a month’s treatment with red yeast rice is $16-37, and the cost of generic lovastatin is as low as $4 at discount pharmacies.

Why Would Anyone Choose Red Yeast Rice Over a Prescription Statin?

There is no logical reason to do so. Those who choose it are making an irrational decision based on the belief that “natural is better” – a fallacy that Steven Novella demolished here.

Among all the different kinds of complementary and alternative medicine, natural and herbal medicines have the highest prior probability. The history of pharmacology is full of examples where a natural medicine was found to be effective and the active ingredient was isolated, standardized, and became a mainstream treatment. There are few if any examples of a whole natural medicine that was found to be superior (or even equivalent) to a purified pharmaceutical containing the active ingredient. Even in a case like this, where natural red yeast rice was shown to be effective, there are compelling reasons to prefer the regulated pharmaceutical version.


Posted by Harriet Hall

Harriet Hall, MD also known as The SkepDoc, is a retired family physician who writes about pseudoscience and questionable medical practices. She received her BA and MD from the University of Washington, did her internship in the Air Force (the second female ever to do so),  and was the first female graduate of the Air Force family practice residency at Eglin Air Force Base. During a long career as an Air Force physician, she held various positions from flight surgeon to DBMS (Director of Base Medical Services) and did everything from delivering babies to taking the controls of a B-52. She retired with the rank of Colonel.  In 2008 she published her memoirs, Women Aren't Supposed to Fly.