Red Yeast Rice: Everything You Need to Know

Megan Nunn, PharmD
·9 min read
1

A medicinal food used for lowering cholesterol.

Medically reviewed by Allison Herries, RDN

Red yeast rice (RYR) is formed by fermenting white rice with a fungus, typically Monascus purpureus. It's used as a flavoring agent, a food preservative, and to help with circulation and digestion in traditional Chinese medicine.

As a dietary supplement, RYR has been a popular alternative to prescription cholesterol medications called statins. In the United States alone, annual spending on RYR has been about $20 million annually.

This article discusses the proven benefits of RYR, along with some important side effects and precautions to be aware of if you decide to try it.



Red Yeast Rice Supplement Facts

  • Active Ingredient(s): Monacolins (including monacolin K), pigments (including citrinin), stigmasterol, organic acids, and amino acids (including gamma-aminobutyric acid)

  • Alternate Names(s): Monascus purpureus, koji, anka, angkak or ben-koji

  • Legal Status: Over-the-counter (OTC) dietary supplement (United States)

  • Suggested Dose: 1 to 2 grams (g) per day for high cholesterol

  • Safety Considerations: Not recommended during pregnancy or breastfeeding. RYR may also interact with grapefruit juice and prescription medications such as statins and antibiotics.



Red Yeast Rice Controversy

RYR can contain many active ingredients, depending on how it is produced. The most studied ingredient is monacolin K, identical to the prescription medicine lovastatin, sold under the brand names Mevacor and Altoprev in the United States. Lovastatin is used to lower cholesterol levels in the blood.

The Food and Drug Administration (FDA) banned the sale of RYR products that contain monacolin K since it is the same chemical found in lovastatin.

However, an investigation of RYR supplements sold in the United States revealed a significant variation in monacolin K content, ranging from 0 to 5.4 milligrams (mg) per capsule.

Uses of Red Yeast Rice



Explainer

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian nutritionist (RDN), pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.



RYR has primarily been studied for its cholesterol-lowering effect. It is commonly used to self-treat high cholesterol and protect against heart disease. Here's the latest evidence of its effectiveness.

May Lower Cholesterol

High cholesterol is a risk factor for heart attacks and strokes. Statins typically are the first-line treatment for people with high cholesterol to lower the risk of heart disease, the leading cause of death worldwide.

RYR may be a good option for people with high cholesterol who cannot take statins due to side effects or for another reason. RYR may also benefit people with slightly increased cholesterol levels that are not high enough to warrant statin treatment.

A systematic review found that RYR may lower low-density lipoprotein cholesterol (LDL, or "bad" cholesterol) by a little over 1 millimole per liter (mmol/L, more commonly represented as 38 mg per deciliter, or mg/dL) vs. placebo. This reduction in LDL can lower the risk of heart disease by 15% to 20%.

RYR's ability to lower cholesterol levels is due primarily to monacolin K. Scientists think the effectiveness of each RYR product is related to the amount of monacolin K it contains.

The average daily dose of monacolin K in the clinical trials studied was 10.8 mg. RYR supplements containing this monacolin K level were shown to be as effective as moderate-intensity statins in decreasing LDL cholesterol. Taking 10 mg of monacolin K daily may lower LDL cholesterol by up to 25% over six to eight weeks.

Remember that RYR supplements sold in the United States typically do not list the amount of monacolin K they contain on the label per FDA guidelines. This is because it's the same ingredient as the FDA-approved prescription drug lovastatin. Some RYR supplements don't contain any monacolin K, though most contain at least some. Because of this, cholesterol-lowering effects may vary considerably between different products regarding.

Another review found that RYR lowered both total and LDL cholesterol in adults. It also increases high-density lipoprotein cholesterol (HDL, or "good" cholesterol), which may protect the heart.

May Protect Against Heart Attacks

Researchers studied the effects of RYR in people with previous heart attacks who had borderline high cholesterol levels. They found that taking RYR can decrease the following:

<p>Hendra Su / Getty Images</p> Red yeast rice

Hendra Su / Getty Images

Red yeast rice

Additional Uses

The most evidence for RYR is related to its ability to lower cholesterol. But it's also been studied for conditions such as:

Mostly, these studies are preliminary, meaning conducted in animal models or test tubes and not humans. Human trials have been scarce and either small or inconclusive.

There isn't enough evidence to recommend RYR for any of these conditions.

What Are the Side Effects of Red Yeast Rice?

Your healthcare provider may recommend taking RYR supplements to lower cholesterol or for another reason.

Remember that just because supplements are natural doesn't mean they are safe or a good choice for everyone. Taking a supplement like RYR may cause side effects. These side effects can be common or severe.

Common Side Effects

Depending on the levels of monacolin K in the product, RYR may cause side effects similar to those caused by statin drugs. These can include the following:

In clinical trials, less than 5% of people who took RYR developed liver or kidney injury. Up to 23% of people who took RYR reported muscle symptoms.

Still, daily levels of 3 to 10 mg of monacolin K are generally considered to cause minimal side effects. The tricky part is that product labels do not state how much monacolin K is present in RYR supplements, so you can't be sure how much you're getting.

And keep in mind that most clinical trials only lasted up to 12 weeks, so more long-term trials on safety are needed.

Severe Side Effects

Serious side effects of RYR can be due to monacolin K or citritin, a contaminant found in some products. These side effects include the following:

Precautions

Do keep the following precautions in mind when using RYR:

  • Severe allergic reaction: Avoid using RYR if you have a known allergy to it or its ingredients, including lovastatin. Ask your pharmacist or healthcare provider for a complete list of the ingredients if you're unsure.

  • Pregnancy: RYR is not recommended during pregnancy due to safety issues. Citrinin, a harmful contaminant in some RYR products, may cause birth defects.

  • Breastfeeding: RYR is not recommended during breastfeeding due to a lack of safety studies.

  • Adults over age 65: RYR has been studied and deemed safe in a large group of adults between ages 65 and 75. People in the study took RYR for over four years. Remember that older adults are likely to take prescription medications or other dietary supplements that could interact with RYR. Discuss taking RYR with your healthcare provider to ensure no significant drug interactions will occur.

  • Children: A short-term trial of RYR plus another supplement called policosanol suggested it may be safe for children ages 8 to 16 with genetic causes of high cholesterol. The trial was small (only 40 children), though. Children should not be given RYR as this population lacks safety data. Discuss this supplement with your pediatrician for more information.

  • Other modifications: People who are statin-intolerant, meaning they can't take statins due to muscle symptoms, should be cautious when using RYR as it may cause the same side effects as statins do. RYR should also be used cautiously in people with liver disease and those who drink alcohol.

Dosage: How Much Red Yeast Rice Should I Take?



Explainer

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.



Clinical trials of RYR's effects on cholesterol have used doses ranging from 1,200 to 4,800 mg daily.



Takeaway

Dietary supplements are not regulated like prescription medications in the United States. Therefore, some may be safer than others. When choosing a supplement, consider factors such as third-party testing, potential drug interactions, and other safety concerns. Talk to a healthcare provider or a registered dietitian nutritionist (RD or RDN) about supplement quality and safety.



What Happens If I Take Too Much Red Yeast Rice?

Taking more RYR than recommended or with statins can increase the risk of side effects like muscle pain (myopathy) or breakdown (rhabdomyolysis).

The European Food Safety Agency (EFSA) has determined an upper limit (UL) for citrinin, sometimes produced when RYR is made.

Citrinin can be toxic to the kidneys.

The maximum daily dose of citrinin is 20 micrograms per kilogram (μg/kg).

Interactions

RYR should not be taken along with statins as it could lead to an overdose.

Taking RYR with some medicines and foods can increase the risk of side effects like muscle damage. Some examples of these interacting medicines include:

The cholesterol-lowering effects of RYR may be increased when it's taken with other supplements such as:

It is essential to carefully read a supplement's ingredients list and nutrition facts panel to know which ingredients and how much of each ingredient is included. Please review the supplement label with your healthcare provider to discuss potential interactions with foods, other supplements, and medications.

Similar Supplements

Some other nutraceuticals (foods with medicinal effects) that have been found to lower LDL cholesterol include:

RYR is the most effective nutraceutical for reducing cholesterol levels.

Food Sources of Red Yeast Rice

RYR may be found in rice wines, some vinegars, and tofu.

It has also traditionally been used in East Asian cuisine to add color or flavor to food and as a preservative.

Summary

RYR is a popular dietary supplement proven to lower cholesterol levels and is often viewed as a "natural statin."

But keep in mind that "natural" does not always mean safe. As with other supplements, discussing taking RYR with your healthcare provider before you start taking it is essential.

Your provider can help ensure that it won't interact with other prescriptions or supplements you currently take. They can also help you monitor its effect on your cholesterol levels to ensure it's working.

Remember that monacolin K is not regulated, and results can differ dramatically between RYR products.

Frequently Asked Questions

How much monacolin K is found in red yeast rice?

It varies and depends on the fermentation method and the yeast strain used in manufacturing. A wide range of monacolin K has been found in commercial products in the United States, from 0 mg to 5.4 mg per capsule. Most labels do not list monacolin K content.

What are the side effects of red yeast rice?

Typical side effects of RYR include muscle pain, gastrointestinal (GI) distress (stomach pain, nausea, or diarrhea), fatigue, and headache.

How does RYR compare to pharmacological treatment with statins?

RYR, which contains 10 mg of monacolin K, has been shown to lower LDL cholesterol about as much as moderate-intensity statins do. Remember that monacolin K in any product can vary up to sixtyfold. Lower levels of monacolin K may not lower cholesterol much, while higher levels are more likely to cause side effects.

Read the original article on Verywell Health.