Red Yeast Rice: What You Need To Know
What is red yeast rice?
Red yeast rice is produced by fermentation of a yeast on rice. The yeast is usually Monascus purpureus.
Depending on the yeast strain used and the conditions of fermentation, the yeast can enrich the rice with substances known as monacolins, including monacolin K. Monacolin K is structurally identical to the medicine lovastatin.
Lovastatin, like other statin drugs, helps slow the production of cholesterol in the body to decrease the amount of cholesterol that may build up on the walls of arteries and block blood flow to the heart, brain, and other parts of the body. Statin drugs are used together with diet, weight loss, and exercise to reduce the risk of heart attack and stroke.
How much monacolin K is in red yeast rice?
Traditional red yeast rice may contain trace amounts of monacolin K (lovastatin).
Some commercial red yeast rice products contain very little or no detectable monacolin K. Other products, however, have been found to contain large amounts of monacolin K. Some researchers reported that commercial lovastatin is illegally added to some red yeast rice products.
It’s impossible for consumers to know the amount of monacolin K in red yeast rice products. Levels of monacolin K and lovastatin are not usually included on product labels. A 2017 review analyzed 28 brands of red yeast rice products from mainstream retailers in the United States, and none of the products included the quantity of monacolin K on the label. Monacolin K was not detected in two brands, and in the 26 brands that contained monacolin K, the quantity ranged more than 60-fold, from 0.09 to 5.48 mg per 1,200 mg of red yeast rice.
How does the U.S. Food and Drug Administration (FDA) regulate red yeast rice products?
According to the FDA, red yeast rice products that have enhanced or added lovastatin—which is structurally identical to monacolin K—cannot be marketed as a dietary supplement in the United States. This regulation is based on the FDA’s approval of lovastatin as a new drug before it was ever marketed as a food or dietary supplement.
On several occasions, the FDA sent warning letters to companies selling red yeast rice products that had enhanced or added lovastatin, telling the companies to correct their violations.
Are red yeast rice products effective?
Red yeast rice products that have considerable amounts of monacolin K may effectively lower blood cholesterol levels, blood glucose levels, and blood pressure. They may also reduce the risk of heart problems and death in people with metabolic syndrome. (Metabolic syndrome, also called insulin resistance syndrome, is a group of conditions that raise the risk of heart disease, diabetes, and stroke.) But, because of the levels of monacolin K, these products are considered by the FDA to be unapproved new drugs and are not sold legally in the United States.
Other red yeast rice products may contain very little monacolin K, and it’s unknown if these products are effective in reducing cholesterol levels or improving other areas of health. Some products have levels of monacolin K that are below the level known to lower cholesterol in clinical trials.
Are red yeast rice products safe?
A 2019 systematic review of clinical trials suggested that red yeast rice products with varying levels of monacolin K were safe. But that went against the opinion of the European Food Safety Authority (EFSA), published in 2018, which concluded that exposure to monacolin K from red yeast rice products could lead to severe side effects. The EFSA panel could not identify a guaranteed safe dietary level of monacolins from red yeast rice products.
What are possible side effects from red yeast rice products?
Red yeast rice products that contain significant amounts of monacolin K can have the same potential side effects as statin drugs, including muscle, kidney, and liver damage. They may also cause digestive problems (such as diarrhea, nausea, and stomach pain) and other reported side effects.
Red yeast rice products can have the same types of drug interactions as statin drugs and therefore may interfere with certain medicines or increase the chance for side effects.
Are there other safety concerns with red yeast rice products?
Yes. Some red yeast rice products contain a contaminant called citrinin, which is toxic and can damage the kidneys.
In a 2021 analysis of 37 red yeast rice products, only one had citrinin levels below the maximum level currently set by the European Union. Also, four products that were contaminated with citrinin were labeled as “citrinin-free.”
Are red yeast rice products safe during pregnancy?
There are no studies on the safety of red yeast rice products during pregnancy or while breastfeeding. Red yeast rice products are not recommended for those who are pregnant or lactating.
For More Information
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.
Toll-free in the U.S.: 1-888-644-6226
Telecommunications relay service (TRS): 7-1-1
Email: firstname.lastname@example.org (link sends email)
Know the Science
NCCIH and the National Institutes of Health (NIH) provide tools to help you understand the basics and terminology of scientific research so you can make well-informed decisions about your health. Know the Science features a variety of materials, including interactive modules, quizzes, and videos, as well as links to informative content from Federal resources designed to help consumers make sense of health information.
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
Toll-free in the U.S.: 1-877-NHLBI4U (1-877-645-2448)
Email: email@example.com (link sends email)
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) and fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements).
Email: firstname.lastname@example.org (link sends email)
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.
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.
- Cohen PA, Avula B, Khan IA. Variability in strength of red yeast rice supplements purchased from mainstream retailers. European Journal of Preventive Cardiology. 2017;24(13):1431-1434.
- Consumer Lab Product Reviews. Red Yeast Rice Supplements Review. Accessed at www.consumerlab.com/reviews/red-yeast-rice-supplements-review/red-yeast-rice on May 27, 2022.
- European Food Safety Authority (EFSA) Panel on Food Additives and Nutrient Sources Added to Food (ANS), Younes M, Aggett P, et al. Scientific opinion on the safety of monacolins in red yeast rice. EFSA Journal. 2018;16(8):e05368.
- Fogacci F, Banach M, Mikhailidis DP, et al. Safety of red yeast rice supplementation: a systematic review and meta-analysis of randomized controlled trials. Pharmacological Research. 2019;143:1-16.
- Food and Drug Administration. Warning Letter: Dr. Sam Robbins, Inc. dba HFL Solutions, LLC, MARCS-CMS 608729, August 28, 2020. Accessed at www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/dr-sam-robbins-inc-dba-hfl-solutions-llc-608729-08282020 on May 27, 2022.
- Food and Drug Administration. Warning Letter: Ip-6 International Inc., FLA-14-10, April 23, 2014. Accessed at web.archive.org/web/20140526231131/http://www.fda.gov/iceci/enforcementactions/warningletters/2014/ucm396822.htm on May 27, 2022.
- Righetti L, Dall’Asta C, Bruni R. Risk assessment of RYR food supplements: perception vs. reality. Frontiers in Nutrition. 2021;8:792529.
- Song J, Luo J, Ma Z, et al. Quality and authenticity control of functional red yeast rice—a review. Molecules. 2019;24(10):1944.
- Yuan R, Yuan Y, Wang L, et al. Red yeast rice preparations reduce mortality, major cardiovascular adverse events, and risk factors for metabolic syndrome: a systematic review and meta-analysis. Frontiers in Pharmacology. 2022;13:744928.
- Chen C-H, Yang J-C, Uang Y-S, et al. Improved dissolution rate and oral bioavailability of lovastatin in red yeast rice products. International Journal of Pharmaceutics. 2013;444(1-2):18-24.
- 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.
- Marley E, Brown P, Leeman D, et al. Analysis of citrinin in cereals, red yeast rice dietary supplement, and animal feed by immunoaffinity column cleanup and LC with fluorescence detection. Journal of AOAC International. 2016;99(4):1025-1031.
- National Heart, Lung, and Blood Institute. What Is Metabolic Syndrome? Accessed at www.nhlbi.nih.gov/health/metabolic-syndrome on May 31, 2022.
- Raschi E, Girardi A, Poluzzi E, et al. Adverse events to food supplements containing red yeast rice: comparative analysis of FAERS and CAERS reporting systems. Drug Safety. 2018;41(8):745-752.
- Russo R, Gallelli L, Cannataro R, et al. When nutraceuticals reinforce drugs side effects: a case report. Current Drug Safety. 2016;11(3):264-266.
- Twarużek M, Ałtyn I, Kosicki R, et al. Dietary supplements based on red yeast rice—a source of citrinin? Toxins (Basel). 2021;13(7):497.
NCCIH thanks D. Craig Hopp, Ph.D., and David Shurtleff, Ph.D., NCCIH, for their review of the 2022 update of this publication.
This publication is not copyrighted and is in the public domain. Duplication is encouraged.
NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). 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 NCCIH.