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Red yeast

What is it?

Red yeast is the product of rice fermented with Monascus purpureus yeast. Red yeast supplements are different from red yeast rice sold in Chinese grocery stores. People use red yeast as medicine.

Red yeast is used for maintaining desirable cholesterol levels in healthy people, reducing cholesterol in people with high cholesterol, for indigestion, diarrhea, improving blood circulation, and for spleen and stomach health.

In foods, red yeast is used as a food coloring for Peking duck.

The active ingredient in red yeast is the same as the active ingredient in prescription drugs called statins used for high cholesterol. That’s why red yeast has all the possible side effects, drug interactions, and precautions associated with this type of drug. The American Heart Association warns against using red yeast until the results of long-term studies are in. You should talk with your healthcare provider if you plan to take red yeast.

You may have come across a red yeast product called Cholestin, manufactured by Pharmanex. It was one of the most widely studied red yeast products. Originally, Cholestin contained the same active ingredient found in statin drugs. This caused the U.S. Food and Drug Administration (FDA) to call Cholestin an unapproved drug. Cholestin was reformulated so that its active ingredient is now something else.

How effective is it?

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for RED YEAST are as follows:

Possibly effective for...

  • Lowering high cholesterol. Some research showed that taking a specific red yeast product for two to three months could significantly lower total and “bad cholesterol” (low-density lipoprotein (LDL) cholesterol) levels and triglycerides (another type of blood fat). But, this specific product contained large amounts of a chemical similar to "statin" drugs, such as lovastatin. Statins are approved by the FDA to lower cholesterol. In the U.S., the FDA now considers this product and other red yeast products that contain statins to be illegal unapproved drugs. However, outside the U.S., these specific red yeast products are still available.
    Some red yeast products available in the U.S. these days contain little or no statins. It is not known if these products do much to reduce cholesterol levels in people with high cholesterol.
    Some other products still contain significant amounts of statins. One analysis shows that that some of these products can contain up to 5 mg of statins per tablet.
  • Lowering high cholesterol and triglyceride levels caused by human immunodeficiency virus (HIV) disease (AIDS).

Insufficient evidence to rate effectiveness for...

  • Indigestion.
  • Diarrhea.
  • Improving blood circulation.
  • Spleen and stomach problems.
  • Other conditions.
More evidence is needed to rate the effectiveness of red yeast for these uses.

How does it work?

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Red yeast supplements are manufactured by culturing Monascus purpureus yeast on rice at carefully controlled temperature and growing conditions to increase the concentrations of chemicals that lower blood cholesterol and triglycerides. These chemicals are similar to the prescription drugs known as "statins," including lovastatin (Mevacor) and others.

Are there safety concerns?

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Red yeast is POSSIBLY SAFE for most people when taken by mouth for up to 3 months. There isn't enough information to know if taking it for longer periods is safe. It can cause stomach discomfort, heartburn, intestinal gas, headache, and dizziness.

Red yeast contains chemicals similar to the prescription drugs called "statins." Therefore, red yeast might also cause side effects similar to statin drugs, such as liver damage and severe muscle pain and muscle damage.

There is also concern about product quality. Many red yeast rice products have been found to contain varying amounts of the statin-like chemicals. Some products may contain none and others may contain high amounts, which are more likely to cause serious side effects.

Serious allergic reactions can occur after breathing in red yeast.

Red yeast that is not fermented correctly may contain citrinin. Citrinin is a poison that may cause kidney damage.

Special precautions & warnings:

Pregnancy and breast-feeding: Red yeast is LIKELY UNSAFE during pregnancy. It has caused birth defects in animals. Not enough is known about the safety of using red yeast during breast-feeding. Don’t use during pregnancy or breast-feeding.

Liver disease: Red yeast contains chemicals that are the same as the statin drug lovastatin. Like statin drugs, red yeast should be avoided in people with liver problems.

Are there interactions with medications?

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Do not take this combination.

Medications that can harm the liver (Hepatotoxic drugs)
Red yeast contains the statin drug lovastatin. Lovastatin might harm the liver in some people. Taking red yeast along with other medications that might also harm the liver might increase the risk of liver damage. Do not take red yeast if you are taking another medication that can harm the liver.

Some medications that can harm the liver include acetaminophen (Tylenol and others), amiodarone (Cordarone), carbamazepine (Tegretol), isoniazid (INH), methotrexate (Rheumatrex), methyldopa (Aldomet), fluconazole (Diflucan), itraconazole (Sporanox), erythromycin (Erythrocin, Ilosone, others), phenytoin (Dilantin), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and many others.


Be cautious with this combination.

Drinking alcohol might harm the liver. Red yeast might also harm the liver. Taking red yeast along with alcohol might increase the risk of liver damage. Do not drink alcohol if you are taking red yeast.

Cyclosporine (Neoral, Sandimmune)
Red yeast might affect the muscles. Cyclosporine (Neoral, Sandimmune) might also affect the muscles. Taking red yeast along with cyclosporine (Neoral, Sandimmune) might cause serious side effects.

Gemfibrozil (Lopid)
Gemfibrozil (Lopid) can affect the muscles. Red yeast can also affect the muscles. Taking gemfibrozil along with red yeast might increase the risk of muscle problems.

Medications that decrease the break down of other medications in the liver (Cytochrome P450 3A4 (CYP3A4) inhibitors)
Some medications are changed and broken down by the liver. Some medications might decrease how quickly the liver breaks down red yeast. Taking red yeast along with some medications that decrease the breakdown of other medications in the liver can increase the effects and side effects of red yeast. Before taking red yeast, talk to your healthcare provider if you are taking any medications that are changed by the liver.

Some medications that might decrease how quickly the liver breaks down red yeast include amiodarone (Cordarone), clarithromycin (Biaxin), diltiazem (Cardizem), erythromycin (E-mycin, Erythrocin), indinavir (Crixivan), ritonavir (Norvir), saquinavir (Fortovase, Invirase), and many others.

Medications used for lowering cholesterol (Statins)
Red yeast can help lower cholesterol. Taking red yeast along with other medications used to lower cholesterol might increase the risk of adverse effects. Do not take red yeast if you are already taking medications used for lowering cholesterol.

Some medications used for high cholesterol include cerivastatin (Baycol), atorvastatin (Lipitor), lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), and others.

Niacin can affect the muscles. Red yeast can also affect the muscles. Taking niacin along with red yeast might increase the risk of muscle problems.

Are there interactions with herbs and supplements?

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Coenzyme Q-10 (CoQ10, Ubiquinone)
Red yeast can lower levels of coenzyme Q-10.

Grapefruit can slow the rate at which the body uses up red yeast. This could increase the amount of the red yeast in the body and increase its effects and side effects.

Herbs and supplements that might harm the liver
Red yeast contains statin-like drugs. Statins can harm the liver. Taking red yeast along with other herbs and supplements that can harm the liver might increase the risk of liver damage. Some products that might harm the liver include androstenedione, chaparral, comfrey, DHEA, germander, kava, niacin, pennyroyal oil, and others.

St. John's wort
St. John's wort can lower serum levels of the statin drug lovastatin. Red yeast contains statin-like drugs such as lovastatin. So St. John's wort might reduce the effects from using of red yeast.

Are there interactions with foods?

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Red yeast contains the statin drug lovastatin. Lovastatin can cause liver damage in some people. Theoretically, drinking alcohol along with red yeast might increase the risk of liver damage.

Taking red yeast with food gets it into the system faster.

Grapefruit can slow the rate at which the body uses up red yeast. This could increase the amount of the red yeast in the body and increase its effects and side effects.

What dose is used?

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The following doses have been studied in scientific research:

  • High cholesterol: 1200 mg to 2400 mg of red yeast once or twice daily. Only products containing chemicals similar to the prescription “statin” cholesterol drugs have been shown to lower cholesterol levels. Many of these products provide approximately 5-10 mg of the statin drug called lovastatin.
  • High cholesterol related to HIV infection: 1200 mg twice daily.

Other names

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Arroz de Levadura Roja, Cholestin, Hong Qu, Koji Rouge, Levure de Riz Rouge, Monascus, Monascus purpureus, Monascus Purpureus Went, Red Rice, Red Rice Yeast, Red Yeast Rice, Red Yeast Rice Extract, Riz Rouge, Xue Zhi Kang, XueZhiKang, XZK, Zhibituo, Zhi Tai.


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To learn more about how this article was written, please see the Natural Medicines Comprehensive Database methodology.methodology (


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To see all references for the Red yeast page, please go to

  1. Karl M, Rubenstein M, Rudnick C, Brejda J. A multicenter study of nutraceutical drinks for cholesterol (evaluating effectiveness and tolerability). J Clin Lipidology 2012;6:150-158.
  2. Huang HN, Hua YY, Bao GR, Xie LH. The quantification of monacolin K in some red yeast rice from Fujian province and the comparison of the other product. Chem Pharm Bull (Tokyo) 2006;54:687-9.
  3. Gordon RY, Cooperman T, Obermeyer W, Becker DJ. Marked variability of monacolin levels in commercial red yeast rice products: buyer beware! Arch Intern Med 2010;170:1722-7.
  4. 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. Am J Cardiol 2010;105:198-204.
  5. Becker DJ, Gordon RY, Halbert SC, et al. Red yeast rice for dyslipidemia in statin-intolerant patients: A randomized trial. Ann Intern Med 2009;150:830-9.
  6. Lapi F, Gallo E, Bernasconi S, et al. Myopathies associated with red yeast rice and liquorice: spontaneous reports from the Italian Surveillance System of Natural Health Products. Br J Clin Pharmacol 2008;66:572-74.
  7. Liu J, Zhang J, Shi Y, et al. Chinese red yeast rice (Monascus purpureus) for primary hyperlipidemia: a meta-analysis of randomized controlled trials. Chin Med 2006;1:4.
  8. Safety of red yeast rice. Pharmacist's Letter / Prescriber's Letter 2008;24:241203.
  9. Roselle H, Ekatan A, Tzeng J, et al. Symptomatic hepatitis associated with the use of herbal red yeast rice. Ann Intern Med 2008;149:516-7.
  10. Mueller PS. Symptomatic myopathy due to red yeast rice. Ann Intern Med 2006;145:474-5.
  1. Rogers JD, Zhao J, Liu L, et al. Grapefruit juice has minimal effects on plasma concentrations of lovastatin-derived 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors. Clin Pharmacol Ther 1999;66:358-66.
  2. 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. J Altern Complement Med 2001;7:133-9.
  3. Prasad GV, Wong T, Meliton G, Bhaloo S. Rhabdomyolysis due to red yeast rice (Monascus purpureus) in a renal transplant recipient. Transplantation 2002;74:1200-1.
  4. Keithley JK, Swanson B, Sha BE, et al. A pilot study of the safety and efficacy of cholestin in treating HIV-related dyslipidemia. Nutrition 2002;18:201-4.
  5. Wigger-Alberti W, Bauer A, Hipler UC, Elsner P. Anaphylaxis due to Monascus purpureus-fermented rice (red yeast rice). Allergy 1999;54:1330-1.
  6. Bliznakov EG. More on the Chinese red-yeast-rice supplement and its cholesterol-lowering effect. Am J Clin Nutr 2000;71:152-7.
  7. Havel R. Dietary supplement or drug? The case of cholestin. Am J Clin Nutr 1999;69:175-6.
  8. US Dept Health, Human Services, FDA. Pharmanex, Inc, administrative proceeding, public docket #97P-0441: final decision. Available at:
  9. Kou W, Lu Z, Guo J. [Effect of xuezhikang on the treatment of primary hyperlipidemia]. Zhonghua Nei Ke Za Zhi 1997;36:529-31.
  10. Wang J, Lu A, Chi J. Multicenter clinical trial of the serum lipid-lowering effects of a monascus purpureus (red yeast) rice preparation from traditional Chinese medicine. Cur Ther Res 1997;58:964-78.
  11. Mortensen SA, Leth A, Agner E, Rohde M. Dose-related decrease of serum coenzyme Q10 during treatment with HMG-CoA reductase inhibitors. Mol Aspects Med 1997;18:S137-S144.
  12. Ghirlanda G, Oradei A, Manto A, et al. Evidence of plasma CoQ10-lowering effect by HMG-CoA reductase inhibitors: a double-blind, placebo-controlled study. J Clin Pharmacol 1993;33:226-9.
  13. Bargossi AM, Battino M, Gaddi A, et al. Exogenous CoQ10 preserves plasma ubiquinone levels in patients treated with 3-hydroxy-3-methyglutaryl coenzyme A reductase inhibitors. Int J Clin Lab Res 1994;24:171-6.
  14. Anon. Court backs Food & Drug Administration's check of cholestin. (Accessed 25 July 2000).
  15. Folkers K, Langsjoen P, Willis R, et al. Lovastatin decreases coenzyme Q levels in humans. Proc Natl Acad Sci USA 1990;87:8931-4.
  16. Heber D, Yip I, Ashley JM, et al. Cholesterol-lowering effects of a proprietary Chinese red-yeast-rice dietary supplement. Am J Clin Nutr 1999;69:231-6.
  17. Hebel SK, ed. Drug Facts and Comparisons. 52nd ed. St. Louis: Facts and Comparisons, 1998.
  18. Piscitelli SC, Burstein AH, Chaitt D, et al. Indinavir concentrations and St John's wort. Lancet 2000;355:547-8.
  19. Kantola T, Kivisto KT, Neuvonen PJ, et al. Grapefruit juice greatly increases serum concentrations of lovastatin and lovastatin acid. Clin Pharmacol Ther 1998 63:397-402.
  20. Robbers JE, Tyler VE. Tyler's Herbs of Choice: The Therapeutic Use of Phytomedicinals. New York, NY: The Haworth Herbal Press, 1999.
  21. McKevoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
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Last reviewed - 07/08/2013

Page last updated: 01 July 2014