Natural Medical SolutionsRed yeast rice is rice that has been fermented with a red mold. It is sold as a supplement for high cholesterol. It is unusual among supplements, because it can contain a substance that is identical to a prescription statin drug.
What is red yeast rice?
Red yeast rice is made by growing a mold on rice. The mold is usually one called Monascus purpureus. Labels say "yeast", but it is really a mold.
As it grows, the mold can make substances called monacolins. One of them is monacolin K.
Monacolin K is the same substance as lovastatin. Lovastatin is a prescription statin drug. Statins slow down how much cholesterol your body makes.
So a red yeast rice capsule can hold a real statin, sold as a supplement.
What are the side effects of red yeast rice?
Products with a meaningful amount of monacolin K can cause the same side effects as statin drugs. NCCIH lists:
- Muscle damage
- Kidney damage
- Liver damage
- Stomach problems, such as diarrhea, feeling sick and stomach pain
There is a second problem that has nothing to do with statins. Some red yeast rice is contaminated with citrinin. Citrinin is a poison that can harm your kidneys.
This is not rare. In a 2021 test of 37 products, only one was below the citrinin limit set by the European Union. Four products that were contaminated were labeled "citrinin-free".
How much monacolin K is in a bottle?
There is no way for you to know. That is the honest answer.
The amount is almost never printed on the label. A 2017 review looked at 28 brands sold in the United States. Not one listed how much monacolin K it held.
The amounts varied more than 60 times over between brands. Two brands had none at all.
So two bottles that look the same can be very different. One may do nothing. Another may act like a low dose statin.
Does red yeast rice lower cholesterol?
Products with a good amount of monacolin K may lower cholesterol. They may also lower blood sugar and blood pressure.
But here is the catch. The FDA treats those stronger products as unapproved drugs. They are not sold legally in the United States.
The products you can buy legally may contain very little monacolin K. Some hold less than the amount shown to lower cholesterol in studies. Whether those weaker products help at all is unknown.
Is red yeast rice legal in the United States?
It depends on the product. The FDA says red yeast rice with added or boosted lovastatin cannot be sold as a dietary supplement.
The reason is timing. Lovastatin was approved as a drug before anyone sold it as a supplement, so it stays a drug.
The FDA has sent warning letters to companies breaking this rule. Some researchers have also reported that plain lovastatin is added illegally to some products.
Is red yeast rice safe?
Experts do not agree, and it is worth knowing that.
A 2019 review of clinical trials suggested these products were safe.
The European Food Safety Authority reached a different view in 2018. It concluded that monacolin K from these products could cause severe side effects. Its panel could not name any amount it was willing to call safe.
Who should not take red yeast rice?
Do not take it if you are pregnant or breastfeeding. There are no studies on safety in pregnancy, and NCCIH does not recommend it.
Talk to your doctor first if any of these apply:
- You already take a statin or any cholesterol medicine
- You have liver or kidney problems
- You have had muscle pain on a statin before
- You take any prescription medicine at all
Does Red Yeast Rice interact with any medications?
Talk to your doctor and pharmacist before taking red yeast rice if you take any prescription medicine. The list below is not complete.
NCCIH states that red yeast rice products can have the same types of drug interactions as statin drugs. Because the amount in the bottle is unknown, so is the size of the risk.
Tell your pharmacist you take it. Ask them to check it the way they would check a statin prescription.
Taking red yeast rice on top of a prescribed statin means taking two sources of the same kind of substance. Your doctor needs to know.
Common questions about red yeast rice
Is red yeast rice a natural statin?
Why does the strength vary so much between brands?
What is citrinin?
Can I take red yeast rice instead of my statin?
Related on this site
Where this information comes from
Written from NCCIH (National Center for Complementary and Integrative Health), a public-domain resource from the U.S. National Institutes of Health. Information retrieved 2026-08-21.
Ready to heal naturally?
Start your personalized naturopathic, functional & holistic care plan in Roswell, GA, proudly serving Alpharetta, Atlanta & the north metro.
