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Red yeast rice
Overview
Red yeast rice, also called Went Yeast, has been used for centuries in China as both food and medicine. It is made by fermenting a type of yeast called Monascus purpureus over red rice. In Chinese medicine, red yeast rice is used to lower cholesterol, improve blood circulation, and improve digestion.
Red yeast rice contains chemicals that are similar to prescription statin medications. One of these, called monacolin K, has the same makeup as the drug lovastatin (Mevacor). Doctors prescribe statins to lower LDL ("bad") cholesterol levels and help reduce the risk of heart disease.
Researchers are not sure if red yeast rice lowers cholesterol because of the statin-like chemical or because of other things in red yeast rice, such as unsaturated fatty acids, isoflavones, and phytosterols. But because many red yeast rice supplements did have monacolin, the Food and Drug Administration (FDA) considered them to be drugs. Manufacturers were supposed to remove any red yeast rice products with monacolin from the market. As a result, many of the red yeast rice products you can buy may not contain monacolin. Unfortunately, there is no way to tell whether a product contains moacolin because it is not listed on the label.
Therapeutic Uses
Prevention
Several studies have shown that red yeast rice lowers LDL ("bad") cholesterol levels. High cholesterol levels raise the risk of heart disease. Red yeast (Monascus purpureus) stops the action of an enzyme in the body that helps make cholesterol.
Red yeast rice contains substances known as monacolins. One of these, monacolin K, has the same chemical makeup as lovastatin (Mevacor), a prescription drug that lowers cholesterol. Some researchers think that is why red yeast rice lowers cholesterol. Others point out that the amount of monacolin in red yeast rice is less than you would find in the prescription drug. They think there may be other substances in red yeast rice that help lower cholesterol. More research is needed.
Treatment
Several studies suggest that red yeast rice reduces high cholesterol. However, most of the studies have used a formulation of red yeast rice, Cholestin, which is no longer available in the U.S. You can still buy Cholestin, but it no longer has any red yeast rice. The FDA requires any red yeast product that has monacolin to be taken off the market.
These studies support the claim that red yeast rice lowers cholesterol:
Dietary Sources
Asia, and Chinese communities in North America, use red yeast rice in powdered form as a food coloring for fish, alcoholic beverages, and cheese.
Dosage and Administration
Red yeast rice is an ingredient in several supplements advertised to promote heart health. Red yeast rice is also available in commercial preparations. One of the proprietary products most often studied was Cholestin, which contained monacolin. However, that product is no longer on the market. The current ingredients in Cholestin do not include red yeast rice.
Pediatric
People younger than 20 should not use red yeast rice supplements.
Adult
In Traditional Chinese Medicine (TCM), the dosage of dietary or supplemental red yeast rice can be quite high. But the right dose for adults may be different, depending on the form of the supplement. Most studies have used standardized extract: 600 mg, 2 to 4 times daily.
Precautions
Researchers do not know whether it is safe to use red yeast rice for longer than 12 weeks.
People with liver disease, and those at risk for liver disease, should not take red yeast rice. Red yeast rice may affect the function in the same way prescription drugs to lower cholesterol can.
These people should not take red yeast rice: people with kidney disease, thyroid problems, or musculoskeletal disorders, or those at higher risk of cancer.
People who drink more than two alcoholic beverages a day, have a serious infection or physical condition, or have had an organ transplant should also avoid using red yeast rice.
Side Effects
Side effects of red yeast rice are rare but can include:
Pregnancy and Breastfeeding
Pregnant and breastfeeding women should not take red yeast rice.
Pediatric Use
People under 20 should not take red yeast rice until more research is done.
Geriatric Use
No studies have looked at the safety of red yeast rice in older adults. However, elderly people who took 1,200 mg per day of red yeast rice in an 8 week study had no major side effects.
Interactions and Depletions
Cholesterol-lowering medications: If you take drugs to lower your cholesterol, you should not take red yeast rice unless your doctor tells you to. Red yeast rice may make the effect of these drugs stronger, increasing the risk of liver damage. If you are already taking a statin or other drug to lower cholesterol, talk to your doctor before taking red yeast rice.
Anticoagulants (blood-thinners): Red yeast rice may increase the risk of bleeding. Blood thinners include warfarin (Coumadin), clopidogrel (Plavix), and daily aspirin.
Grapefruit juice: If you take a statin, grapefruit and grapefruit juice can increase the amount of the drug in your blood. That can give you a greater chance of side effects and liver damage. Because red yeast rice may act like statins in the body, you should not drink grapefruit juice or eat grapefruit while taking red yeast rice.
Coenzyme Q10 (CoQ10): Statins can lower the amount of CoQ10 in the body. CoQ10 is very important in heart and muscle health and in energy production. Not having enough CoQ10 can cause fatigue, muscle aches and pains, and muscle damage. Red yeast rice also may lower amounts of CoQ10 in the body. Ask your doctor if you need to take CoQ10 while you are taking red yeast rice products.
Other medications: Because it acts like a statin, red yeast rice may pose the same potential risk of liver damage that statins do, when combined with other prescription medications that also affect the liver. Some of these include:
Supporting Research
Becker DJ, French B, Morris PB, Silvent E, Gordon RY. Phytosterols, red yeast rice, and lifestyle changes instead of statins; a randomized, double-blinded, placebo-controlled trial. Am Heart J. 2013;166(1):187-96.
Becker DJ, Gordon RY, Halbert SC, French B, Morris PB, Rader DJ. Red yeast rice for dyslipidemia in statin-intolerant patients: a randomized trial. Ann Intern Med. 2009;150(12):830-9.
Becker DJ, Gordon RY, Morris PB, Yorko J, Gordon YJ, Li M, Iqbal N. Simvastatin vs therapeutic lifestyle changes and supplements: randomized primary prevention trial. Mayo Clin Proc. 2008 Jul;83(7):758-64.
Bonovich, K, Colfer H, Davidson M, Dujovne C, Greenspan M, Karlberg R, et al. A Multi-Center, Self-Controlled Study of Cholestin In Subjects With Elevated Cholesterol. American Hear Association. 39thAnnual Conference on Cardiovascular Disease Epidemiology and Prevention, Orlando, Fl. March 1999.
Havel R. Dietary supplement or drug? The case of cholestin. Am J Clin Nutr. 1999;69(2):175-176.
Heber D, Yip I, Ashley JM, Elashoff DA, Go VLW. Cholesterol-lowering effects of a proprietary Chinese red-yeast-rice dietary supplement. Am J Clin Nutr. 1999;69:231-236.
Huang CF, Li TC, Lin CC, Liu CS, Shih HC, Lai MM. Efficacy of Monascus purpureus Went rice on lowering lipid ratios in hypercholesterolemic patients. Eur J Cardiovasc Prev Rehabil. 2007 Jun;14(3):438-40.
Li C, Li Y, Hou Z. Toxicity study for Monascus purpureus (red yeast) extract. Information of the Chinese Pharmacology Society. 1995;12(4):12 [Translation].
Li C, Zhu Y, Wang Y, Zhu J, Chang J, Kritchevsky D. Monascus Purpureus-Fermented Rice (Red Yeast Rice): A natural food product that lowers blood cholesterol in animal models of hypercholesterolemia. Nutrition Research. 1998;18(1):71-81.
Li Y, Jiang L, Jia Z, et al. A meta-analysis of red yeast rice: an effective and relatively safe alternative approach for dyslipidemia. PLoS One. 2014;9(6):e98611.
Liu J, Zhang J, Shi Y, Grimsgaard S, Alraek T, Fønnebø V. Chinese red yeast rice (Monascus purpureus) for primary hyperlipidemia: a meta-analysis of randomized controlled trials. Chin Med. 2006 Nov 23;1:4.
Ma J, Li Y, Ye Q, Li J, Hua Y, Ju D, et al. Constituents of red yeast rice, a traditional Chinese food and medicine. J Agric Food Chem. 2000;48:5220-5225.
Mark D. All red yeast rice products are not created equal. The Am J of Cardiol. 106(3).
Mueller PS. Symptomatic myopathy due to red yeast rice. Ann Intern Med. 2006;145(6):474-5.
Ong HT, Cheah JS. Statin alternatives or just placebo: an objective review of omega-3, red yeast rice and garlic in cardiovascular therapeutics. Chin Med J (Engl). 2008 Aug 20;121(16):1588-94.
Qin S, Zhang W, Qi P, Zhao M, Dong Z, Li Y , et al. Elderly patients with primary hyperlipidemia benefited from treatment with a Monacus purpureus rice preparation: A placebo-controlled, double-blind clinical trial. American Heart Association. 39th Annual conference on Cardiovascular Disease Epidemiology and Prevention, Orlando, Fl. March 1999.
Shamim S, Al Badarin FJ, DiNicolantonio JJ, Lavie CJ, O'Keefe JH. Red yeast rice for dysipidemia. Mo Med. 2013;110(4):349-54.
Wang J, Lu Z, Chi J, Wang W, Su M, Kou W, et al. Multicenter clinical trial of serum lipid-lowering effects of a Monascus purpureus (red yeast) rice preparation from traditional Chinese medicine. Curr Ther Res. 1997;58(12):964-978.
Venero C, Venero J, Wortham D, Thompson P. Lipid-lowering efficacy of red yeast rice in a population intolerant to statins. The Am J Cardiol. 2010;105(5):664-6.
Vercelli L, Mongini T, Olivero N, Rodolico C, Musumeci O, Palmucci L. Chinese red rice depletes muscle coenzyme Q10 and maintains muscle damage after discontinuation of statin treatment. J Am Geriatr Soc. 2006;54(4):718-20.
Alternative Names
Angkak; Beni-koji; Hong qu; Hung-chu; Monascus; Red koji; Red leaven; Red rice; Xue zhi kang; Zhitai
Version Info
What is red yeast rice?
Red yeast rice is rice that has been fermented by the red yeast, Monascus purpureus. It has been used by the Chinese for many centuries as a food preservative, food colorant (it is responsible for the red color of Peking duck), spice, and an ingredient in rice wine. Red yeast rice continues to be a dietary staple in China, Japan, and Asian communities in the United States, with an estimated average consumption of 14 to 55 grams of red yeast rice per day per person.
Red yeast rice also has been used in China for over 1,000 years for medicinal purposes. Red yeast rice was described in an ancient Chinese list of drugs as useful for improving blood circulation and for alleviating indigestion and diarrhea.
Recently, red yeast rice has been developed by Chinese and American scientists as a product to lower blood lipids, including cholesterol and triglycerides.
What is the present status of red yeast rice?
Small scale studies using pharmaceutical-grade red rice yeast have continued to demonstrate efficacy and safety. However, in the United States it is no longer legal to sell supplements of red yeast rice that contain more than trace amounts of cholesterol lowering substances. For example, the active ingredients of red rice yeast have been removed from Cholestin marketed in the United States. (Hypocol, another product containing red yeast rice is no longer being sold in the United States.)
The reasons the Food and Drug Administration (FDA) has ruled that it is illegal to sell red yeast rice that contains more than trace amounts of the cholesterol-lowering substances and to promote red yeast rice for lowering cholesterol levels.
What are the different preparations of red yeast rice?
There are three major preparations of red yeast rice:
Zhitai
Zhitai is produced by the fermentation of a mixture of different strains of Monascus purpureus on whole grain rice. Zhitai contains mainly rice and yeast, but is mostly rice by weight.
Cholestin or HypoCol
Cholestin or HypoCol is produced by the fermentation of selected strains of Monascus purpureus, using a proprietary process that produces a certain concentration of monacolin K (monacolin K is lovastatin, which is believed to be the major cholesterol-lowering ingredient).
Xuezhikang
Xuezhikang is produced by mixing the rice and red yeast with alcohol and then processing it to remove most of the rice gluten. Xuezhikang contains 40% more cholesterol-lowering ingredients than Cholestin or Hypocol.
In Singapore, red yeast rice is available as Hypocol (NatureWise, Wearnes Biotech & Medicals (1998) PTE LTD).
What is the composition of HypoCol and Cholestin?
At one time, Cholestin contained red yeast rice, and at that time scientists at Pharmanex and the UCLA Center for Human Nutrition analyzed the properties Cholestin. The composition by weight is:
There are no additives, preservatives, heavy metals, or toxic substances, such as citrinic acid.
In 1977, Professor Endo in Japan discovered a natural cholesterol-lowering substance that is produced by a strain of Monascus yeast. This substance inhibits HMG-CoA reductase, an enzyme that is important for the production of cholesterol in the body. Professor Endo named this substance moncacolin K. Since then, scientists have discovered a total of eight monacolin-like substances that have cholesterol-lowering properties.
Monacolin K is lovastatin, the active ingredient in the popular statin drug, lovastatin (Mevacor), which is used for lowering cholesterol. Lovastatin also is believed to be the main cholesterol-lowering ingredient in HypoCol. The lovastatin in Mevacor is highly purified and concentrated, the lovastatin in HypoCol is not. Thus, they contain much lower concentrations of lovastatin than Mevacor. For example, each 600-mg capsule of Cholestin contains less than 2.4 mg of lovastatin (when this ingredient was contained in the product), whereas tablets of Mevacor contain 10 mg or more of this ingredient.
Because none of the components are purified and concentrated, HypoCol and Cholestin (marketed outside of the US) contain a mixture of the eight yeast-produced monacolins, unsaturated fatty acids, and certain anti-oxidants. Some scientists believe that these other monacolins, unsaturated fatty acids, and anti-oxidants may work together favorably with lovastatin to enhance its cholesterol-lowering effects, as well as its ability in lowering triglycerides and increasing HDL cholesterol. (HDL is considered the "good" form of cholesterol since high levels of HDL cholesterol protect against heart attacks.) Further studies in animals and humans will be necessary to test these theories. Continue Reading
How effective are HypoCol, Cholestin, and Xuezhikang in lowering lipids?
Chinese scientists conducted most of the animal and human studies on this issue, using either Zhitai or Xuezhikang. The results of some 17 studies involving approximately 900 Chinese subjects with modestly elevated cholesterol levels have been published. In eight ofthese studies, there was a control group that received a placebo (a pill with no active ingredients) for comparison purposes. In nine of the studies, there was no placebo control group.
These studies consistently showed that Zhitai and Xuezhikang:
Scientists at the UCLA Center for Human Nutrition studied Cholestin in a 12-week, double blind, placebo-controlled trial involving 83 American adults with borderline-high to moderately elevated cholesterol. They found that Cholestin (when red yeast rice was an ingredient in this product) reduced total cholesterol, LDL cholesterol, and triglyceride levels but had no effect on HDL cholesterol. This study was published in the American Journal of Clinical Nutrition (1999;69:231-7).
Lowering LDL and increasing HDL cholesterol prevents atherosclerosis (a build-up of plaque) of the heart's arteries. Since atherosclerosis causes heart attacks, lowering the LDL and increasing HDL cholesterol should lower the risk of heart attacks. In fact, several large, long-term, placebo-controlled clinical trials have shown clearly that lowering LDL cholesterol with diet and statin drugs [pravastatin (Pravachol) , lovastatin (Mevacor), and simvastatin (Zocor) reduces the risk of heart attacks. No large, long-term studies of red yeast rice products for the prevention of heart attacks have yet been conducted. However, animal studies are underway at UCLA comparing red yeast rice to a statin drug (such as Mevacor) for the prevention and treatment of atherosclerosis. Continue Reading
How safe are red yeast rice products?
Animal studies have been conducted in China using high doses of red yeast rice products. No damage to the kidneys, liver, or other organs were demonstrated in these studies.
Human trials in China and in the United States reported only rare and minor side effects of heartburn or indigestion with the use red yeast rice products. No liver, kidney, or muscle toxicity has been reported.
However, human trials in the United States and China have generally lasted only a few weeks to a few months. Thus, conclusive proof of long term safety (over a period of many years) will have to await further data (such as from data received after the products have been marketed or long-term clinical trials).
Scientists conducting the studies generally believe that red yeast rice is safe in the long-term since it has been a food staple for thousands of years in Asian countries without reports of toxicity. They attribute the safety of red yeast rice products to the process of preparation that does not involve the isolation and concentration of a single ingredient. Although it is true that isolation andconcentration enhance the potency of a single ingredient, these factors also increase the risk of side effects.
Are there any precautions in consuming red yeast rice products?
Not all red yeast rice products contain the same concentrations of the cholesterol-lowering ingredients. Moreover, it is illegal in the United States to sell red yeast rice products that contain more than trace amounts of cholesterol lowering substances. Therefore, the red yeast rice products that are available in the United States do not contain levels of cholesterol lowering substances that are likely to cause side effects. Nevertheless, certain products also may contain unacceptably high levels of an undesirable and toxic substance called citrinic acid. Continue Reading
Who are suitable candidates for red yeast rice products?
There is not yet consensus among scientists and doctors as to the role, if any, of red yeast rice in treating elevated cholesterol. Therefore a doctor familiar with a patient's personal medical condition and his/her family history of heart diseases should be prescribing cholesterol-lowering measures. Generally in the United States, when diet,weight loss, and exercise are insufficient in lowering cholesterol to optimal levels, many doctors recommend using a statin drug since large long-term trials have consistently shown that statins [such as pravastatin (Pravachol), simvastatin (Zocor), lovastatin (Mevacor), and atorvastatin (Lipitor)] are safe and effective in lowering LDL cholesterol and decreasing the risk of heart attacks and strokes. Although similar studies are not available for red yeast rice products, given the minimal amounts of cholesterol lowering substances that they are allowed to contain in the U.S., it would be expected that legal red yeast rice products would not be very effective at lowering cholesterol levels.
Who are not suitable candidates for red yeast rice products?
Patients with moderate to severe cholesterol abnormalities, and patients who are at high risk of developing heart attacks or strokes are not candidates for red yeast rice. Examples of patients that are at high risk of heart attacks include patients who had prior heart attacks and strokes, patients with diabetes mellitus, and patients with atherosclerosis in the arteries that supply blood to the brain and to the extremities (peripheral artery disease). In these patients, red yeast rice containing legal amounts of cholesterol lowering substances (along with weight loss, diet, and exercise) is not potent enough to achieve the degree of cholesterol lowering desired. Continue Reading
Medically reviewed by Robert J. Bryg, MD; Board Certified Internal Medicine with subspecialty in Cardiovascular Disease
REFERENCE:
American Journal of Clinical Nutrition (1999; 69:231-7)
On This Page
© asian-ingredients
Red yeast rice is a traditional Chinese culinary and medicinal product. In the United States, dietary supplements containing red yeast rice have been marketed to help lower blood levels of cholesterol and related lipids. Red yeast rice products may not be safe; some may have the same side effects as certain cholesterol-lowering drugs, and some may contain a potentially harmful contaminant. This fact sheet provides basic information about red yeast rice, summarizes scientific research on effectiveness and safety, discusses the legal status of red yeast rice, and suggests sources for additional information.
Key Facts
About Red Yeast Rice
Red yeast rice is made by culturing rice with various strains of the yeast Monascus purpureus. Some preparations of red yeast rice are used in food products in Chinese cuisine, including Peking duck. Others have been sold as dietary supplements to lower blood levels of cholesterol and related lipids.
Some red yeast rice products contain substances called monacolins, which are produced by the yeast. Monacolin K is chemically identical to the active ingredient in the cholesterol-lowering drug lovastatin, which is one of the drugs in the category known as statins. These drugs lower blood cholesterol levels by reducing the production of cholesterol by the liver.
The composition of red yeast rice products varies depending on the yeast strains and culture conditions used to manufacture them. The strains and conditions used to produce culinary red yeast rice differ from those used to produce products that are intended to lower cholesterol. Tests performed by the FDA indicate that the red yeast rice sold as a food product contains only traces of monacolin K or none at all.
In both 2008 and 2009, the most recent years for which data are available, sales of red yeast rice dietary supplements were approximately $20 million per year. According to the 2007 National Health Interview Survey, which included a comprehensive survey of the use of complementary health approaches by Americans, 2.1 percent of respondents (an estimated 1.8 million Americans) had used complementary health approaches for cholesterol in the past year.
Safety
What the Science Says
Red yeast rice products that contain substantial amounts of monacolin K can lower blood cholesterol levels. Researchers have not reported results of any studies of red yeast rice products that contain little or no monacolin K, so whether these products have any effect on blood cholesterol is unknown.
Results of Clinical Trials
In clinical trials (studies in people) of red yeast rice products that contained substantial amounts of monacolin K, the products lowered blood levels of total cholesterol and low-density lipoprotein (LDL) cholesterol (the so-called bad cholesterol that is linked to increased heart disease risk). It is important to emphasize that all of these clinical trials used products that contained substantial amounts of monacolin K. A 2011 analysis showed that some of the red yeast rice products on the market contain very little monacolin K. These products may have little or no effect on blood cholesterol levels. Therefore, even though the participants in the clinical trials were able to lower their cholesterol levels by taking red yeast rice, you might not be able to achieve the same results.
In one of the clinical trials, the tested product produced a cholesterol-lowering effect greater than would be expected based on its monacolin K content. Further investigations, supported by the National Center for Complementary and Integrative Health (NCCIH), suggested that other monacolins or other substances present in the product may have contributed to its cholesterol-lowering effect.
Tolerability of Red Yeast Rice Products
Two studies supported by NCCIH have indicated that some people who had been unable to tolerate statin drugs because of side effects (muscle pain or weakness) were able to tolerate red yeast rice. It is uncertain whether the smaller amount of monacolin K in the red yeast rice products, as compared with the amounts of active ingredients in the drugs, accounted for the greater tolerability or whether other factors were responsible.
Legal Status of Red Yeast Rice
In 1998, the FDA determined that a red yeast rice product that contained a substantial amount of monacolin K was an unapproved new drug, not a dietary supplement. On several occasions since then, the FDA has taken action against companies selling red yeast rice products that contain more than trace amounts of monacolin K, warning them that it is against the law to market these products as dietary supplements.
Despite the FDA actions, some red yeast rice products currently on the market in the United States may contain monacolin K. (Some products tested as recently as 2011 have been found to contain it in substantial amounts.) Other products may contain little or none of this component. Consumers have no way of knowing how much monacolin K is present in most red yeast rice products, and therefore have no way of knowing whether a particular product is safe, effective, or legal. The labels on these products usually state only the amount of red yeast rice that they contain, not the amounts of monacolin K or other monacolins.
If You Are Considering Red Yeast Rice
For More Information
NCCIH Clearinghouse
The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.
National Heart, Lung, and Blood Institute (NHLBI)
The NHLBI Health Information Center provides information to health professionals, patients, and the public about heart, lung, and blood diseases and sleep disorders and accepts orders for publications.
P.O. Box 30105
Bethesda, MD 20824-0105
Phone: 301-592-8573, or dial 7-1-1 for access to free Telecommunications Relay Services (TRS)
Office of Dietary Supplements (ODS), National Institutes of Health (NIH)
ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need to Know), fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements), and the PubMed Dietary Supplement Subset.
PubMed®
A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed.
NIH Clinical Research Trials and You
The National Institutes of Health (NIH) has created a Web site, NIH Clinical Research Trials and You, to help people learn about clinical trials, why they matter, and how to participate. The site includes questions and answers about clinical trials, guidance on how to find clinical trials through ClinicalTrials.gov and other resources, and stories about the personal experiences of clinical trial participants. Clinical trials are necessary to find better ways to prevent, diagnose, and treat diseases.
Research Portfolio Online Reporting Tools Expenditures & Results (RePORTER)
RePORTER is a database of information on federally funded scientific and medical research projects being conducted at research institutions.
Key References
Acknowledgments
NCCIH thanks the following people for their technical expertise and review of this publication: Ram Gordon, M.D., Chestnut Hill Hospital, Philadelphia; Zhaoping Li, Ph.D., M.D., David Geffen School of Medicine, University of California at Los Angeles; and Craig Hopp, Ph.D., and John (Jack) Killen, Jr., M.D., NCCIH.
This publication is not copyrighted and is in the public domain. Duplication is encouraged.
What Is Red Yeast Rice?
Red yeast rice is a traditional Chinese culinary and medicinal product that's used to treat cholesterol levels and other ailments.
It's made by fermenting various strains of Monascus purpureus yeast on rice.
Red yeast rice (sometimes called RYR) typically contains compounds that are similar to the active ingredients in prescription drugs called statins, which are used to treat high cholesterol.
In particular, RYR may contain monacolin K, a compound that's chemically identical to the cholesterol-lowering drug lovastatin (Mevacor).
Because of its monacolin K content, RYR has all of the possible side effects, drug interactions, and precautions as lovastatin.
Some research suggests RYR is effective at reducing LDL cholesterol and triglyceride levels, possibly because of monacolin K.
Red yeast rice is also used to help with other health conditions, although its effectiveness is unknown. These conditions include:
In 1998, the Food and Drug Administration (FDA) banned the sale of the RYR product Cholestin until it reformulated.
The FDA considered Cholestin an unapproved drug (rather than a supplement, which the FDA does not regulate) because it had an active amount of monacolin K.
Since then, RYR manufacturers are supposed to remove from the U.S. market any products that have more than trace amounts of monacolin K.
However, as long as they don't claim their products lower cholesterol or contain monacolin K, they aren't subject to FDA action, and consumers have no way of knowing just how much of it they're consuming.
In 2010, there were at least 31 products with RYR available to U.S. consumers, according to a study published that year in the journal Archives of Internal Medicine.
The researchers tested 12 products sold online and at U.S. stores and found that the amount of monacolin (including monacolin K) varied widely.
In 2014, the company Doctor's Best recalled more than 7,000 bottles of its RYR dietary supplement because it contained undeclared amounts of monacolin K.
Red Yeast Rice Warnings
Some RYR products contain a poison called citrinin (if the yeast isn't fermented correctly), which can cause kidney failure.
One-third of the RYR products tested in the 2010 U.S. study contained citrinin.
A 2014 study in the journal Food Control also found that 35.1 percent of RYR dietary supplements in Taiwan contained citrinin.
If you have any health issues, be sure to tell your doctor if you are taking or have taken RYR.
Because it contains chemicals similar to statins, RYR supplements may cause liver damage, muscle damage, and severe muscle pain.
You shouldn't take RYR if you have:
Breathing in red yeast may cause serious allergic reactions.
If you think you might be having any serious reaction to RYR, call your doctor or get medical help right away.
Pregnancy and Red Yeast Rice
Do not take RYR if you are pregnant -- red yeast has caused birth defects in animals.
You also should not take RYR if you are breastfeeding because it may be unsafe to your infant.
Red Yeast Rice Side Effects
RYR has all of the possible side effects, drug interactions, and precautions as the prescription drug lovastatin because of RYR's potential monacolin K content.
Taking RYR supplements may cause:
Severe Side Effects of Red Yeast Rice
Stop taking RYR and call your doctor if you experience muscle aches and weakness, because you may have rhabdomyolysis, a rare condition in which muscle fibers break down and release substances into the bloodstream.
Red Yeast Rice Interactions
Talk to you doctor before taking RYR.
You should also tell your doctor about any prescription, non-prescription, and over-the-counter (OTC) medications, illegal or recreational drugs, herbal remedies, and nutritional and dietary supplements you're taking.
In addition, before you take any other medicines, be sure to tell your doctor or pharmacist if you are taking RYR.
Red Yeast Rice and Drug Interactions
Red yeast rice may negatively interact with:
Red Yeast Rice and Alcohol
Don't drink alcohol while taking RYR because the combination can increase your risk of liver damage.
Red Yeast Rice and Grapefruit
Grapefruit and grapefruit juice can slow the rate that the body metabolizes statins, allowing more of the drug to remain circulating in the body and increasing the risk of side effects and liver damage.
The same thing might be true with RYR because of its potential monacolin K content.
Therefore, it's best to avoid all grapefruit products while taking red yeast rice.
Red Yeast Rice and Other Interactions
Do not take RYR with herbs and supplements that might harm the liver, including:
Red Yeast Rice Dosage
Red Yeast Rice Overdose
It's not known what occurs during an RYR overdose.
If you suspect an overdose, you should contact a poison-control center or go to an emergency room immediately.
You can reach a poison-control center at (800) 222-1222.