Red Yeast Rice

Medically Reviewed by Jabeen Begum, MD on February 27, 2024
7 min read

Red yeast rice extract (RYRE) is a traditional Chinese medicine believed to lower cholesterol. Several types of the extract are sold as supplements.

RYRE is a substance that's extracted from rice that's been fermented with a type of yeast called Monascus purpureus. It's been used in China and other Asian countries for centuries as a traditional medicine. It's also used as a food coloring, additive, and preservative.

RYRE naturally contains several ingredients that may help control cholesterol levels. These include a number of monacolins, most importantly monacolin K. It also contains sterols, isoflavones, and monounsaturated fatty acids, or "healthy fats."

Red yeast rice may be appealing because it's "natural," but you need to be careful. Experts have not studied it extensively. The ideal dosing and its long-term safety are unclear. It could be dangerous for some people. And because the ingredients of different brands of RYRE might vary so much, it's hard to make firm statements about its effectiveness or safety.

Confusingly, the answer is both. One of the most important ingredients in RYRE is monacolin K. It's also known as lovastatin, the active ingredient in the prescription drug Mevacor.

While the extract is a traditional remedy known to help lower cholesterol, the pharmaceutical manufacturer of Mevacor argues that it owns the rights to the ingredient lovastatin.

This confusion extends to how the supplement is sold in the U.S. The FDA has requested that several RYRE products be withdrawn from the market because they contain monacolin K, which is chemically identical to the prescription drug lovastatin. The FDA cited a risk of severe muscle problems that could lead to kidney disease.

Despite the FDA's attempts, many people in the U.S. still manage to get similar RYRE products from other countries or on the Internet.

Red yeast rice offers various health benefits for people who take it. They include:

Lowers cholesterol

One of the primary uses for red yeast rice is to lower cholesterol. The chemicals found in red yeast rice lower the amounts of "bad" cholesterol (also known as LDL ) in the body by lowering its production in the liver.

After you eat, LDL cholesterol inside your food gathers with other substances in your body’s blood vessels. A buildup of too much LDL can lead to heart attacks or strokes. However, the liver makes LDL cholesterol too.

LDL isn’t all bad, though. It does help your body make cells and hormones. Still, it’s best to keep the amount of LDL cholesterol low to help your overall heart health.

Lowers stroke risk

Since red yeast rice helps lower cholesterol, it can also decrease your chances of having a stroke. Low cholesterol reduces the risk of developing dangerous blood clots, which can break and cause strokes and heart attacks. Red yeast rice can also reduce your risk of other diseases caused by high blood pressure, such as chest pain (angina) and heart failure. 

Improves blood circulation

Plaques in blood vessels also clog arteries and reduce circulation. Red yeast rice has been shown to help improve circulation, allowing wounds to heal more quickly and letting your body function at its best. Even those who don’t have plaque buildup in their blood vessels can benefit from better circulation, as the muscles and organs get more oxygen when blood is flowing well.

Red yeast rice products can vary by type and chemical composition, so they don't all work similarly. Some are chemically similar to statins, which are medications known to help lower cholesterol. Other strains may contain these chemicals in varying concentrations.

Studies have shown that certain red yeast rice products that contain statin can significantly lower levels of total cholesterol, specifically LDL, or "bad" cholesterol. One showed that taking 2.4 grams per day reduced LDL levels by 22% and total cholesterol by 16% in 12 weeks. Another study showed that taking 1.2 grams per day lowered LDL levels by 26% in just 8 weeks.

However, the results of these studies depend on the amount of statin that is in the extract, and it can vary widely. The FDA considers extracts that contain statins to be illegal in the U.S., but many are still available.

Herbal supplements don’t have regulations or manufacturing protocols, so there is no guarantee that the red yeast rice supplement you are taking has a certain level of the component that helps lower cholesterol, monacolin K. It could have high levels, or it could have close to none. The label usually won’t say whether a particular supplement has monacolin K, and it won’t specify the amount.

Keep in mind that the amount of monacolin, perhaps the most important ingredient, in a red yeast rice product can vary a lot. There are many different strains of the yeast. Different types of fermentation are used. One study of different brands of red yeast rice supplements showed that the amount of monacolin ranged from 0% to 0.58%.

So even though studies have shown that RYRE can lower cholesterol, you can't really know if the supplement brand you're using will have that effect.

As with other supplements, the typical daily dosage of red yeast rice is high. Studies have evaluated the benefits of 600 milligrams taken two to four times a day, for a total of 1,200 to 2,400 milligrams. Since there is no way of knowing how much of the beneficial chemical compounds are present in your supplement, it’s best to start with a smaller dose and then have your cholesterol checked to see if it’s working.

Studies have shown that red yeast rice has mild side effects such as headaches, heartburn, and upset stomach. Side effects from prescription lovastatin include elevation of liver enzymes and muscle enzymes, muscle problems, and liver problems.

But more research needs to be done before we can know about the long-term safety of RYRE. We do know that some types may be more dangerous than others because of high levels of other substances such as citrinic acid.

RYRE also shares some of the same risks as statins, the class of drugs containing lovastatin. Experts say that the risks of lovastatin would logically apply to RYRE -- elevation of liver and muscle enzymes, muscle problems, and liver problems.

The extract may not be safe for everyone. You shouldn't take it if you:

  • Have kidney disease
  • Have liver disease
  • Are pregnant
  • Are breastfeeding

In addition, anyone taking one of the following medicines should not use red yeast rice:

  • Statins to control cholesterol such as lovastatin (Mevacor), rosuvastatin (Crestor), fluvastatin (Lescol), atorvastatin (Lipitor), pravastatin (Pravachol), and simvastatin (Zocor)
  • Other cholesterol drugs such as gemfibrozil (Lopid) and fenofibrate (TriCor)
  • Drugs to suppress the immune system, such as cyclosporine
  • Antifungal drugs such as fluconazole (Diflucan), ketoconazole (Nizoral), and itraconazole (Sporanox)
  • Certain antibiotics such as erythromycin and clarithromycin (Biaxin)
  • Serzone, an antidepressant
  • Protease inhibitors, used to treat HIV

People who have allergies to fungus or yeast should also be wary of using RYRE.

The extract may also interact with other drugs for blood pressure and thyroid problems, as well as with other herbs and supplements you may be taking.

Whatever the state of your health, always talk to your doctor before you start using red yeast rice or any other supplement. Remember that not all brands are equal, and RYRE isn't safe for everyone. Though RYRE looks like a promising treatment, more research needs to be done. For now, you should be cautious.

Since 1998, the FDA has said that red yeast rice products with significant amounts of monacolin K can't be marketed as dietary supplements. In recent years, the FDA has warned companies found to be selling these products and alerted consumers. The following brands of red yeast rice supplements were found to contain lovastatin:

  • CholesLo, a product promoted to lower cholesterol
  • Cholestene, a product promoted for cholesterol management
  • Cholestrix, sold by Sunburst Biorganics
  • Red Yeast Rice and Red Yeast Rice/Policosonal Complex, sold by Swanson Healthcare Products, Inc. and manufactured by Nature’s Value Inc. and Kabco Inc.

What does red yeast rice do for the body?

The benefits of red yeast rice include:

  • Lower cholesterol. The monacolin K in red yeast rice helps lower the amounts of "bad" cholesterol (also known as LDL) in the body by lowering its production in the liver.
  • Lower stroke risk. Low cholesterol resulting from red yeast rice's effect on your body can also reduce your risk of developing blood clots that cause stroke and heart attacks.
  • Improved blood circulation. Red yeast rice has been shown to help improve circulation, allowing wounds to heal more quickly and letting your body function at its best.

When should I take red yeast rice, morning or night?

You can take red yeast rice at any time of the day, but some supplement directions will say to split it into two doses, one at morning and one at night. As red yeast rice acts similarly to the statin lovastatin, some people prefer to take it at night. This is because cholesterol production peaks for most people late in the evening, and the supplement can go to work at that time.

Does red yeast rice affect sleep?

It's possible to have insomnia (trouble sleeping) while taking red yeast rice supplements, but this is rare.