Red Yeast Rice: An Introduction

© asian-ingredients.com.

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 cholesterollowering 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 

• Some red yeast rice products contain substantial amounts of 

monacolin K, which is chemically identical to the active 

ingredient in the cholesterol-lowering drug lovastatin. These 

products may lower blood cholesterol levels and can cause the 

same types of side effects and drug interactions as lovastatin.

• Other red yeast rice products contain little or no monacolin K. It 

is not known whether these products have any effect on blood 

cholesterol levels.

• Consumers have no way of knowing how much monacolin K is 

present in most red yeast rice products. The labels on these 

products usually state only the amount of red yeast rice that 

they contain, not the amount of monacolin K.

• The U.S. Food and Drug Administration (FDA) has determined 

that red yeast rice products that contain more than trace 

amounts of monacolin K are unapproved new drugs and cannot 

be sold legally as dietary supplements.

• Some red yeast rice products contain a contaminant called 

citrinin, which can cause kidney failure.

• Tell all your health care providers about any complementary health 

approaches you use. Give them a full picture of what you do to 

manage your health. This will help ensure coordinated and safe care.

U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES

National Institutes of Health

National Center for Complementary 

and Alternative Medicine
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 cholesterollowering 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 

• The same types of side effects that can occur in patients taking lovastatin as a drug can 

also occur in patients who take red yeast rice products that contain monacolin K. Potential 

side effects include myopathy (muscle symptoms such as pain and weakness), 

rhabdomyolysis (a condition in which muscle fibers break down, releasing substances into 

the bloodstream that can harm the kidneys), and liver toxicity. Each of these three side 

effects has been reported in people who were taking red yeast rice.

• Red yeast rice supplements should not be used while pregnant or breastfeeding.

• Lovastatin can interact with a variety of drugs to increase the risk of rhabdomyolysis; these 

drugs include other cholesterol-lowering agents, certain antibiotics, the antidepressant 

nefazodone, drugs used to treat fungal infections, and drugs used to treat HIV infection. 

Red yeast rice containing monacolin K could interact with drugs in the same way.

• If the process of culturing red yeast rice is not carefully controlled, a substance called 

citrinin can form. Citrinin has been shown to cause kidney failure in experimental animals 

and genetic damage in human cells. In a 2011 analysis of red yeast rice products sold as 

dietary supplements, 4 of 11 products were found to contain this contaminant.

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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 lowdensity 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 Alternative Medicine (NCCAM), 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 NCCAM 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.

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If You Are Considering Red Yeast Rice 

• Do not use red yeast rice to replace conventional care or to postpone seeing your health 

care provider about a health problem.

• Do not use red yeast rice dietary supplements if you are pregnant, trying to become 

pregnant, or nursing a child. If you are considering giving a child a red yeast rice dietary 

supplement, it is especially important to consult the child’s health care provider.

• Do not take red yeast rice in addition to prescription statin drugs.

• Many Web sites, including sales sites, have information about red yeast rice. Be cautious 

when you evaluate information from the Web; not all of it is trustworthy. For more 

information, see the NCCAM fact sheet Evaluating Web-Based Health Resources at 

nccam.nih.gov/health/webresources. 

• Federal regulations for dietary supplements are very different from—and less strict than—

those for drugs. For more information about dietary supplements, see NCCAM’s fact sheet 

Using Dietary Supplements Wisely at nccam.nih.gov/health/supplements/wiseuse.htm. 

• Tell all your health care providers about any complementary health approaches you use. 

Give them a full picture of what you do to manage your health. This will help ensure 

coordinated and safe care. For tips about talking with your health care providers about 

complementary health approaches, see NCCAM’s Time to Talk campaign at 

nccam.nih.gov/timetotalk. 

Key References 

Barnes PM, Bloom B, Nahin RL. Complementary and alternative medicine use among adults and children: United 

States, 2007. CDC National Health Statistics Report #12. 2008.

Becker DJ, Gordon RY, Halbert SC, et al. Red yeast rice for dyslipidemia in statin-intolerant patients. A randomized

trial. Annals of Internal Medicine. 2009;150(12):830-839.

Gordon RY, Becker DJ. The role of red yeast rice for the physician. Current Atherosclerosis Reports. 2011;13(1):73-80.

Gordon RY, Cooperman T, Obermeyer W, et al. Marked variability of monacolin levels in commercial red yeast rice 

products: buyer beware! Archives of Internal Medicine. 2010;170(19):1722-1727.

Halbert SC, French B, Gordon RY, et al. Tolerability of red yeast rice (2,400 mg twice daily) versus pravastatin (20 mg 

twice daily) in patients with previous statin intolerance. American Journal of Cardiology. 2010;105:198-204.

Heber D, Lembertas A, Lu QY, et al. An analysis of nine proprietary Chinese red yeast rice dietary supplements: 

implications of variability in chemical profile and contents. Journal of Alternative and Complementary Medicine.

2001;7(2):133-139.

Klimek M, Wang S, Ogunkanmi A. Safety and efficacy of red yeast rice (Monascus purpureus) as an alternative therapy 

for hyperlipidemia. P&T: A Peer-Reviewed Journal for Formulary Management. 2009;34(6):313-327.

Li Z, Seeram NP, Lee R, et al. Plasma clearance of lovastatin versus Chinese red yeast rice in healthy volunteers. Journal 

of Alternative and Complementary Medicine. 2005;11(6):1031-1038.

U.S. Food and Drug Administration. FDA Warns Consumers to Avoid Red Yeast Rice Products Promoted on Internet as Treatments 

for High Cholesterol: Products Found to Contain Unauthorized Drug. U.S. Food and Drug Administration Web site. Accessed 

at www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2007/ucm108962.htm on March 8, 2012.

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For More Information

NCCAM Clearinghouse

The NCCAM Clearinghouse provides information on NCCAM and complementary 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.

Toll-free in the U.S.: 1-888-644-6226

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615

Web site: nccam.nih.gov

E-mail: info@nccam.nih.gov

The National Heart, Lung, and Blood Institute (NHLBI)

NHLBI, a component of the National Institutes of Health (NIH), provides global leadership for a 

research, training, and education program to promote the prevention and treatment of heart, 

lung, and blood diseases and enhance the health of all individuals so that they can live longer 

and more fulfilling lives.

Web site: www.nhlbi.nih.gov

Office of Dietary Supplements (ODS), 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 (such as vitamin D and black cohosh), 

and the PubMed Dietary Supplement Subset.

Web site: www.ods.od.nih.gov

E-mail: ods@nih.gov

PubMed®

A service of the National Library of Medicine (NLM), PubMed contains publication information 

and (in most cases) brief summaries of articles from scientific and medical journals.

Web site: www.ncbi.nlm.nih.gov/sites/entrez

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NIH Clinical Research Trials and You

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.

Web site: www.nih.gov/health/clinicaltrials/

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.

Web site: projectreporter.nih.gov/reporter.cfm

NIH National Library of Medicine’s MedlinePlus

Red Yeast Listing: www.nlm.nih.gov/medlineplus/druginfo/natural/925.html

Acknowledgments 

NCCAM 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., NCCAM.

This publication is not copyrighted and is in the public domain.

Duplication is encouraged.

NCCAM has provided this material for your information. It is not intended to substitute for the 

medical expertise and advice of your primary health care provider. We encourage you to 

discuss any decisions about treatment or care with your health care provider. The mention of 

any product, service, or therapy is not an endorsement by NCCAM.

National Institutes of Health

♦♦♦

U.S. Department of Health and Human Services

D475

Created June 2012

Updated July 2013