Red yeast rice is the product of yeast ( Monascus purpureus ) grown on rice, and is served as a dietary staple in some Asian countries. It contains several compounds collectively known as monacolins, substances known to inhibit cholesterol synthesis. One of these, “monacolin K,” is a potent inhibitor of HMG-CoA reductase, and is also known as mevinolin or lovastatin (Mevacor®, a drug produced by Merck & Co., Inc).
Red yeast rice extract has been sold as a natural cholesterol-lowering agent in over the counter supplements, such as Cholestin TM (Pharmanex, Inc). However, there has been legal and industrial dispute as to whether red yeast rice is a drug or a dietary supplement, involving the manufacturer, the U.S. Food and Drug Administration (FDA), and the pharmaceutical industry (particularly producers of HMG-CoA reductase inhibitor prescription drugs or “statins”).
The use of red yeast rice in China was first documented in the Tang Dynasty in 800 A.D. A detailed description of its manufacture is found in the ancient Chinese pharmacopoeia, Ben Cao Gang Mu-Dan Shi Bu Yi, published during the Ming Dynasty (1368-1644). In this text, red yeast rice is proposed to be a mild aid for gastric problems (indigestion, diarrhea), blood circulation, and spleen and stomach health. Red yeast rice in a dried, powdered form is called Zhi Tai. When extracted with alcohol it is called Xue Zhi Kang.
NB! The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
Adults (18 years and older)
1200 milligrams of concentrated red yeast powder capsules have been taken two times per day by mouth with food.
The average consumption of naturally occurring red yeast rice in Asia has been reported as 14-55 grams per day.
Children (younger than 18 years)
There is not enough scientific evidence to recommend red yeast for children.
NB! There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
There is one report of anaphylaxis (a severe allergic reaction) in a butcher who touched meat containing red yeast.
Side Effects and Warnings
There is limited evidence on the side effects of red yeast. Mild headache and abdominal discomfort can occur. Side effects may be similar to those for the prescription drug lovastatin (Mevacor®). Heartburn, gas, bloating, muscle pain or damage, dizziness, asthma, and kidney problems are possible. People with liver disease should not use red yeast products.
In theory, red yeast may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. A metabolite of Monascus called mycotoxin citrinin may be harmful.
Pregnancy and Breastfeeding
Prescription drugs with similar chemicals as red yeast cannot be used during pregnancy. Therefore, it is recommended that pregnant or breastfeeding women not take red yeast.