Health Benefits and Side Effects of Red Yeast Rice

What is Red Yeast Rice?

Red yeast rice, Image from Wikimedia CommonsRed yeast rice is the product of fermenting rice with Monascus purpureus yeast. (1) It has been a very important part of traditional Chinese medicine and cooking for more than one thousand years. The Chinese people used red yeast rice to improve blood circulation, treat gastric problems (diarrhea, indigestion), and promote stomach and spleen health. (2) Food coloring for Peking duck is one of the many uses of red yeast rice in Chinese cooking. (1)

What are the Health Benefits of Red Yeast Rice?

Red yeast rice became very popular in the Western world when scientists discovered that it has blood cholesterol-lowering effect. It was found out that red yeast rice has the ability to lower the levels of bad cholesterol and triglycerides in the blood. Bad cholesterols are linked to atherosclerosis – a common arterial disease in which cholesterol deposit plaques form on the inner surfaces of the arteries obstructing blood flow. Cholesterol plaques do not only obstruct blood flow but also hardens the arteries. Atherosclerosis is the major culprit for cases of heart attack and stroke.

What is the Active Ingredient in Red Yeast Rice?

Red yeast rice contains lovastatin – the active ingredient in prescription drugs for lowering blood cholesterol (e.g. Mevacor by Merck & Co., Inc.). Lovastatin inhibits the HMG-CoA reductase, liver enzyme involved in cholesterol synthesis. (2) For its cholesterol-lowering effect, red yeast rice gained popularity in the United States. Red yeast rice supplements under the brand name “Cholestin” was introduced in the United States around the late 1990s by the drug company Pharmanex, Inc.. Sale of Cholestin and other red yeast rice- containing supplements was increasing until the FDA officials pulled them out from the market when they found out that the active ingredient of the supplements is similar to the active ingredient (lovastatin) in strictly controlled prescription drugs for lowering cholesterol like Mevacor. (3)

FDA’s action resulted to the disappearance of red yeast rice supplements in US retail stores and Cholestin has been reformulated without red yeast rice extract. Despite FDA’s order, red yeast rice products are still sold on the internet by various marketers. (3) There has been a legal and commercial dispute as to whether red yeast rice is a dietary supplement or a drug, involving Cholestrin manufacturer, FDA, and the drug industry. (2)

What are the Side Effects of Red Yeast Rice?

Red yeast rice may contain specific proteins that can trigger allergic reaction to some people. Symptoms include itching, rashes, hives, wheezing, breathing difficulty, swelling of tongue, throat, lips, or face, vomiting, and anaphylaxis. Other symptoms can occur. A person should stop taking red yeast rice if he experiences the mentioned allergy symptoms and he should immediately seek medical help to manage the symptoms. (4)

Red yeast rice side effects can be similar to the side effects of drug lovastatin (Mevacor) which include gas, bloating, heartburn, dizziness, asthma, muscle pain & damage, and liver & kidney damage. (2) Note that other side effects can show up. Seek medical attention when you are experiencing any of these red yeast rice side effects.

What Medications can interact with Red Yeast Rice?

Red yeast rice extract can interact with drugs which prescription drug lovastatin interacts to. Alcohol and other drugs (even herbal) that can be toxic to the liver should not be taken together with red yeast rice extract. Increased risk of muscle wasting or kidney damage can occur when red yeast rice extract is taken with cyclosporine, ranitidine, and certain antibiotics. (2)

Red yeast rice extract should not be taken with medications that increase the risk of bleeding. These medications include blood thinners (e.g. warfarin), aspirin, anti-platelet drugs (e.g. Paxil), and non-steroidal anti-inflammatory drugs (NSAIDS, e.g. ibuprofen and naproxen). Even herbal medications that increase the risk of bleeding (like Ginkgo biloba) should be avoided. (2)

Red yeast rice extract can also interact with blood pressure-lowering drugs, thyroid medications, niacin, and digoxin. People with diabetes should be cautioned when taking red yeast rice because it may alter blood sugar levels.  (2)
Always consult your doctor before taking red yeast rice products especially if you are using other chemical and herbal medications in order to avoid drug interactions.


References and Further Reading

  1. Red Yeast Rice (Red Yeast): Uses, Side Effects, Interactions, and Warnings. WebMD
  2. Red Yeast Rice: MedlinePlus Supplements
  3. Red Yeast Rice Side Effects – Red Yeast Dangers. Nutritional-Supplement-Educational-Centre
  4. Red Yeast Rice Medical Facts from