Red Yeast Rice

Red Yeast Rice

Common Names

  • Hong qu
  • Monascus
  • Red yeast
  • Beni-koji
  • monacolin K

For Patients & Caregivers

Red yeast rice appears to lower blood cholesterol and triglyceride levels with few side effects, but there is no evidence that it can treat cancer.

Little is known about the way red yeast rice works. One of its constituents, monacolin K, also known as lovastatin, is an active ingredient in the cholesterol-lowering drug, Mevacor®. The drug works by inhibiting an enzyme essential for the creation of cholesterol in the body. Therefore, it is assumed that red yeast rice works through a similar mechanism.

  • To lower high cholesterol
    A few clinical trials show that the use of red yeast rice can reduce cholesterol and triglyceride levels in the blood.
  • Citrinin, a toxic fermentation byproduct, has been found in a number of preparations of red yeast rice.
  • Grapefruit juice may increase the effects of red yeast rice.
  • Stomach ache
  • Dizziness
  • Flatulence
  • Heartburn
  • Muscular disease resulting in muscle weakness

Case reports

  • A 63-year-old woman developed severe hypertransaminasemia following use of Equisterol, an over-the-counter lipid-lowering product containing guggulsterol and red yeast rice extract, for 6 months. Her symptoms normalized after equisterol was discontinued.
  • A 62-year-old woman developed severe hepatitis following use of red yeast rice capsules for approximately 4 months before admission. Her condition improved after discontinuing red yeast rice.

The U.S. Food and Drug Administration declared that the dietary supplement Cholestin, manufactured by Pharmanex, cannot be marketed as a dietary supplement because it contained lovastatin, a prescription drug.

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For Healthcare Professionals

Cholestin3 ™
Monascus purpureus

Used in China as food and medicine for thousands of years, red yeast rice is the fermented product of the fungus, Monascus purpureus, grown on rice. It was first marketed as a dietary supplement in the United States by Pharmanex under the trade name Cholestin (1). The active constituent, monacolin K, is the same as lovastatin, an active ingredient in the cholesterol-lowering drug (2). A number of clinical trials have demonstrated effectiveness of red yeast rice preparations in reducing cholesterol levels in hyperlipidemic patients (3) (4) (5) (14) (15) (16) (17), but one of the extracts tested did not lower blood pressure in hypertensive patients (20). In another study, co-supplementation with Coenzyme Q10 was found to be associated with improved LDL-cholesterolemia and endothelial reactivity in moderately hypercholesterolemic subjects (22).

It is important to note that several preparations of red rice yeast contain citrinin, a toxic fermentation byproduct (6).

  • High cholesterol

Components such as citrinin, monacolines and monankarin, and monascopyridines have been isolated from red yeast rice (10). Fermentation products are standardized to contain 0.4% 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors. HMG-CoA reductase is the rate-limiting enzyme in endogenous cholesterol biosynthesis (1). The principal HMG-CoA reductase inhibitor is monacolin K, also known as lovastatin (11).

  • Citrinin, a toxic fermentation byproduct, was found at measurable concentrations in a number of preparations (6).
  • Grapefruit juice may increase the effects of red yeast rice (9).

Stomach ache (3), heartburn, dizziness and flatulence (7), liver injury and myopathy (21) (23).

Case reports

  • Anaphylaxis in a 26-year-old man (8) and rhabdomyolysis in a 28-year-old renal transplant recipient (12).
  • A 63-year-old woman developed severe hypertransaminasemia following use of Equisterol, an over-the-counter lipid-lowering product containing guggulsterol and red yeast rice extract, for 6 months. Symptoms normalized after equisterol was discontinued (18).
  • A 62-year-old woman developed severe hepatitis following use of red yeast rice capsules for approximately 4 months before admission. Her condition improved after discontinuing red yeast rice (19).
  • Coenzyme Q10: Red yeast rice contains lovastatin which has been shown to lower coenzyme Q10 levels (13).

  1. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician’s Guide to Herbal Medicine. New York: Springer, 2001.

  2. FDA Talk Paper. FDA determines Cholestin to be an unapproved drug.T98-28. May 20, 1998. Accessed March 1, 2013.

  3. Wang J, et al. Multicenter clinical trial of the serum lipid-lowering effects of a Monascus purpureus (red yeast) rice preparation from traditional Chinese medicine. Current Therapeutic Research, Clinical & Experimental 1997 58(12):964-978.

  4. Keithley JK, Swanson B, Sha BE, Zeller JM, Kessler HA, Smith KY. A pilot study of the safety and efficacy of cholestin in treating HIV-related dyslipidemia. Nutrition 2002;18:201-4.

  5. Thompson Coon JS, Ernst E. Herbs for serum cholesterol reduction: a systematic review. J Fam Pract 2003 Jun;52(6):468-78.

  6. Wigger-Alberti W, Bauer A, Hipler UC, Elsner P. Anaphylaxis due to Monascus purpureus—fermented rice (red yeast rice). Allergy 1999;54:1330-1.

  7. Kantola T, Kivisto KT, Neuvonen PJ. Grapefruit juice greatly increases serum concentrations of lovastatin and lovastatin acid. Clin Pharmacol.Ther. 1998;63:397-402.

  8. Wild D, Toth G, Humpf HU. New monascus metabolites with a pyridine structure in red fermented rice. J Agric Food Chem. 2003;51:5493-6.

  9. Chang YN, Lin YC, Lee CC, Liu BL, Tzeng YM. Effect of rice—glycerol complex medium on the production of Lovastatin by Monascus ruber. Folia Microbiol.(Praha) 2002;47:677-84.

  10. 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.

  11. Ghirlanda G, Oradei A, Manto A, Lippa S, Uccioli L, Caputo S 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.

  12. Lin CC, Li TC, Lai MM. Efficacy and safety of Monascus purpureus Went rice in subjects with hyperlipidemia. Eur J Endocrinol 2005;153(5):679-86.

  13. Huang CF, Li TC, Lin CC, et al. Efficacy of Monascus purpureus Went rice on lowering lipid ratios in hypercholesterolemic patients. Eur J Cardiovasc Prev Rehabil. 2007;14(3):438-40.

  14. Becker DJ, Gordon RY, Morris PB, et al. Simvastatin vs therapeutic lifestyle changes and supplements: randomized primary prevention trial. Mayo Clin Proc. 2008;83(7):758-64.

  15. 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(12):830-9, W147-9.

  16. Roselle H, Ekatan A, Tzeng J, Sapienza M, Kocher J. Symptomatic hepatitis associated with the use of herbal red yeast rice. Ann Intern Med. 2008 Oct 7;149(7):516-7.

  17. Mazzanti G, Moro PA, Raschi E, et al. Adverse reactions to dietary supplements containing red yeast rice: assessment of cases from the Italian surveillance system. Br J Clin Pharmacol. 2017 Jan 17. doi: 10.1111/bcp.13171.

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