Red yeast rice may help your heart and reduce cholesterol levels, inflammation, cancer cell growth, and risk of metabolic syndrome. But it can also have possible health downsides.

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It’s turned up on pharmacy shelves only within the last few decades, but red yeast rice has been prized for its powerful medicinal properties for hundreds of years.

As one of the top natural remedies for high cholesterol levels, red yeast rice is one of the few natural supplements that contain active ingredients virtually identical to those found in prescription medications.

Plus, the benefits of red yeast rice extend beyond lowering cholesterol levels, with emerging research showing that it may also benefit inflammation, metabolic syndrome, blood sugar levels, and more.

Here are the benefits, side effects, and dosage recommendations for red yeast rice.

What is red yeast rice?

Red yeast rice is a type of fermented rice that is produced using specific species of mold, Monascus ruber or Monascus purpureus (1, 2).

It’s been used in traditional Chinese medicine for centuries for its powerful health-promoting properties.

Red yeast rice contains the compound monacolin K — the same active ingredient found in prescription cholesterol-lowering medications like lovastatin (2).

For this reason, it’s often used as a cost-effective alternative to pricey medications to help reduce cholesterol levels and support heart health.

Research has shown other beneficial effects as well, ranging from reduced cancer cell growth to improved blood sugar and insulin levels.

Today, red yeast rice is commonly sold as an over-the-counter supplement marketed to help manage cholesterol and improve overall health.

Summary

Red yeast rice is produced by fermenting rice with a specific species of mold. It contains the same active ingredient as cholesterol-lowering medications and has been studied for other benefits as well.

Potential benefits

The potential benefits of red yeast rice include:

• improved heart health
• reduced risk of metabolic syndrome
• decreased inflammation
• reduced cancer risk

May promote heart health

Heart disease is a serious condition that affects millions and is estimated to account for 31.5% of deaths around the world (3).

High cholesterol — one of the main risk factors for heart disease — can cause arteries to narrow and stiffen, leading to an increased risk of heart attack and stroke (4).

Red yeast rice is commonly used as a natural remedy to help lower cholesterol levels and promote heart health, and can sometimes have fewer adverse side effects than prescription drugs used to treat high cholesterol (5).

One review of 21 studies found that red yeast rice was effective at reducing levels of total and LDL (bad) cholesterol, as well as triglycerides and blood pressure, when combined with statin drugs (6).

Additionally, the monacolin K may also help improve endothelial function, or the flexibility and adaptability of your blood vessels, which is key to maintaining your vascular and heart health (7).

May help treat metabolic syndrome

Metabolic syndrome is a cluster of conditions that increase your risk for chronic conditions, such as heart disease, diabetes, and stroke.

Some of the criteria for metabolic syndrome include high blood pressure, excess body fat, increased blood sugar, and alterations in cholesterol or triglyceride levels (8).

Several studies have found that red yeast rice may help treat some of these risk factors and could be used as a natural treatment to aid in their prevention (9).

One of its most well-documented effects is its ability to lower cholesterol. Research shows that it can effectively reduce both total and LDL (bad) cholesterol levels.

Another small, 18-week study found that a supplement containing red yeast rice was able to reduce blood sugar, insulin levels, and systolic blood pressure (the top number of a reading) in people with metabolic syndrome (10).

Plus, an 8-week study looked at the effects of red yeast rice on mice fed a high fat diet compared with a control group. It found that red yeast rice was able to prevent increases in cholesterol levels and body weight (11).

Could reduce inflammation

Inflammation is a normal immune response designed to protect your body against acute infections and foreign invaders.

However, sustained inflammation is thought to contribute to chronic conditions like diabetes, cancer, and heart disease (12).

Studies show that supplementing with red yeast rice may help reduce inflammation and promote better health in the long term.

For example, a study in 50 people with metabolic syndrome showed that taking a supplement containing red yeast rice and olive extract for 8 weeks reduced levels of oxidative stress — a key cause of chronic inflammation — by up to 20 percent (13).

Similarly, one study found that giving red yeast extract to rats with kidney damage reduced levels of specific proteins involved in inflammation in the body (14).

May have anticancer properties

Although current research is limited to animal and test-tube studies, some evidence suggests that red yeast rice may help reduce the growth and spread of cancer cells.

One study found that giving mice with prostate cancer red yeast rice powder significantly decreased tumor volume compared with a control group (15).

However, more research is needed to evaluate the effects of red yeast rice on other types of cancer in humans.

Specifically, further studies should be done to determine how the potential anticancer effects of red yeast rice may affect the general population.

Summary

Red yeast rice may decrease your risk for heart disease and metabolic syndrome, reduce inflammation in the body, and potentially possess anticancer properties. However, more research is needed.

Downsides

However, there are some potential downsides to red yeast rice as well. They include:

Legal status

Monacolin K is the active compound found in red yeast rice that is commonly extracted and used in cholesterol-lowering statins and medications.

According to the Food and Drug Administration (FDA), red yeast rice products that contain monacolin K should be considered a drug, subjecting them to stricter regulations than standard over-the-counter supplements (16).

Additionally, since 1998, the FDA has taken action against several companies selling red yeast rice extract containing high amounts of monacolin K, noting that it’s illegal to market these products as supplements in the United States.

So red yeast rice supplements are still legal, but they must only contain trace amounts of monacolin K. However, as recently as 2011, some red yeast rice supplements have been found to contain high amounts of monacolin K.

As a consumer, it’s impossible for you to know how much monacolin K a supplement may contain, because only the amount of red yeast rice is disclosed on the label.

Additionally, it is important to note that the FDA doesn’t regulate food supplements the way that drugs are regulated, and nutrition claims made may not be based on scientific evidence. So please speak with your healthcare professional when considering taking red yeast rice.

Side effects

Despite the list of benefits associated with red yeast rice, supplementing with it may come with some adverse effects so it is best to speak with your healthcare professional before taking this supplement.

Gastrointestinal problems like bloating, gas, and stomach pain are some of the most commonly reported side effects of red yeast rice.

In more extreme cases, it can also cause issues like muscle problems, liver toxicity, and allergic reactions, similar to the side effects caused by prescription cholesterol-lowering medications (2).

Because research is still limited on the long-term safety of red yeast rice, it’s also not recommended for women who are pregnant or breastfeeding.

If you notice any adverse symptoms after taking red yeast rice, consider decreasing your dosage or discontinuing use, and consult a trusted healthcare professional.

Medication interactions

Red yeast rice contains monacolin K, the key active component that is used to make statin drugs – which are used to lower cholesterol. For this reason, you shouldn’t take red yeast rice if you’re already taking a statin, unless directed to do so by a healthcare professional.

Red yeast rice may also interact with the same drugs that statins interact with, including other cholesterol-lowering drugs, antibiotics, certain antidepressants, antifungals, and antiretrovirals (16).

If you’re taking any medications, it’s a good idea to speak with a trusted healthcare professional before starting red yeast rice supplementation.

Citrinin formation

Finally, red yeast rice that’s not carefully cultivated can contain a byproduct called citrinin. Citrinin is a mycotoxin, or a toxin that is produced by certain types of mold.

Researchers have noted that it can cause kidney failure in animals and may affect gene expression in humans (15).

Additionally, a 2011 assessment of 11 different red yeast rice supplements available for purchase noted that 4 of those products contained citrinin (16).

Summary

Red yeast rice has several potential downsides. The supplements are legally only allowed to contain trace amounts of monacolin K, but some may contain high amounts. Red yeast rice may also have side effects, interact with certain medications, or be contaminated with the mycotoxin citrinin.

Dosage recommendations

Red yeast rice is available in capsule or tablet form and often formulated in combination with other ingredients, such as CoQ10, nattokinase, or omega-3 fatty acids.

These supplements are widely available in health food stores, pharmacies, and though online retailers.

Doses ranging from 200–4,800 mg have been studied in clinical trials, typically containing about 10 mg of total monacolin (17).

Most major supplement brands on the market generally recommend taking between 1,200–2,400 mg daily, divided into two to three doses.

However, the amount needed to realize the potential benefits has not been scientifically determined, and erring on the side of caution is best to minimize the chances of side effects.

However, given the risk of adverse side effects and safety concerns associated with red yeast rice extract, it’s best to speak with your healthcare provider to determine the best dosage for you.

Additionally, make sure that you choose a high-quality supplement. Here are some ways you can know that you are choosing a product from a reputable manufacturer:

• They produce their supplements in a certified Good Manufacturing Practices (cGMP) facility, meaning it meets Food and Drug Administration criteria.
• Their supplements have been third-party tested for purity and ingredients, ensuring that the supplement is labeled honestly and is free of contaminants. Ideally, they make these third-party reports available for consumers.

Summary

Red yeast rice is widely available in both capsule and tablet form. It’s been studied in doses ranging from 200–4,800 mg, but most supplements recommend 1,200–2,400 mg daily for best results.

The bottom line

Red yeast rice may support heart health and reduce cholesterol levels, inflammation, cancer cell growth, and risk factors of metabolic syndrome. However, the supplement also has a number of potential downsides that should be carefully considered before you decide to start using it.

Working closely with your healthcare professional is the best way to decide if this is the right supplement for you and how to select one that is high quality and from a reputable brand.