# Red Yeast Rice: LDL Results, Label Risks and Who Should Avoid It

Source: https://jilllebofsky.com/red-yeast-rice/
By Claire Hadley, Reviews Editor. Updated November 6, 2026. Facts checked November 6, 2026.

**Quick answer:** Red yeast rice can lower LDL cholesterol because its monacolin K is the same molecule as the statin lovastatin. In 20 pooled trials, LDL fell about 39 mg/dL. But US labels rarely list monacolin K, strength varied more than 60-fold across 28 brands, citrinin contamination is common, and it carries statin side effects. Do not combine it with a statin.

Red yeast rice is a fermented rice product sold as a cholesterol supplement, and this guide explains what it is, how much it lowers LDL, and why its safety record is uneven. We read the NCCIH fact sheet, the FDA ingredient listing, two meta-analyses, two randomized trials, a 28-brand lab test and three reports on the 2024 kidney injuries in Japan.[1][2]
Products that carry real amounts of monacolin K lowered LDL by about 39 mg/dL in a pooled analysis of 20 trials, because monacolin K is the same molecule as the prescription statin lovastatin.[1][4]
Red yeast rice at a glance
What it isRice fermented with the mold Monascus purpureus, which can make monacolin K[1]
Main useLowering LDL cholesterol[1]
Active compoundMonacolin K, structurally identical to lovastatin[1][2]
Best evidence20 randomized studies: LDL down 1.02 mmol/L (about 39 mg/dL) vs placebo[4]
Typical amountsMonacolin K per daily serving ranged from 0.09 to 10.94 mg across 28 US brands[3]
SafetyStatin-type side effects, possible citrinin contamination, no safe level set by EFSA[1]
Who should avoid itPregnant or breastfeeding people, and anyone already taking a statin[1][11]

Red yeast rice LDL results and label risks. Sources: NCCIH, Gerards 2015, Becker 2009, Cohen 2017.
What is red yeast rice?
Red yeast rice is rice that has been fermented with a fungus, usually Monascus purpureus, which can fill the grain with cholesterol-lowering compounds called monacolins. The fungus is technically a mold, but US labels use the name "red yeast rice" anyway.[1] It is sold as a food, as a traditional Chinese medicine and as a dietary supplement.[1]
The compound that matters most is monacolin K. How much of it ends up in the rice depends on the fungal strain and the fermentation conditions.[1] Traditional red rice used in cooking may hold only trace amounts. Some commercial products hold almost none, and others hold a lot.[1]
In Japan the same ingredient is called beni-koji. That name became widely known in 2024, when tablets made from it were linked to kidney injuries, a story we cover below.[9] For other ingredients we have checked the same way, see our supplement ingredient guides.
Does red yeast rice for cholesterol work?
Products that contain a meaningful dose of monacolin K do lower LDL cholesterol, by about 39 mg/dL on average in pooled trials. A 2015 meta-analysis in Atherosclerosis pooled 20 randomized studies that measured the monacolin K content. LDL fell 1.02 mmol/L more than with placebo, and the drop was not different from statin therapy.[4]
This result applies only to products with a known, real dose. NCCIH notes that products with very little monacolin K have unknown effects, and some fall below the level that lowered cholesterol in trials.[1]
The largest outcome trial used Xuezhikang, a partly purified red rice extract made in China. In nearly 5,000 people who had already had a heart attack, major coronary events over about 4.5 years fell from 10.4% on placebo to 5.7% on the extract.[6] That is one specific extract, so its result does not carry over to any bottle on a US shelf.
Key red yeast rice studiesStudyWho and how manyDose and lengthResult
Gerards meta-analysis, 2015[4]20 randomized studiesKnown monacolin K content, variedLDL down 1.02 mmol/L vs placebo; similar to statins
Becker trial, 2009[5]62 adults who quit statins over muscle pain1,800 mg twice daily, 24 weeksLDL down 35 mg/dL vs 15 mg/dL on placebo at week 24
CCSPS (Lu), 2008[6]Nearly 5,000 people after a heart attack, ChinaXuezhikang extract, about 4.5 yearsCoronary events 5.7% vs 10.4% on placebo
Fogacci safety meta-analysis, 2019[7]53 trials, 8,535 peopleVarious dosesNo rise in muscle problems (odds ratio 0.94)

How much does red rice yeast lower cholesterol, and how fast?
In the best US trial, LDL fell 43 mg/dL after 12 weeks and 35 mg/dL after 24 weeks, compared with 11 and 15 mg/dL on placebo. The 2009 trial in the Annals of Internal Medicine enrolled 62 people who had stopped statins because of muscle aches. Everyone also joined a 12-week lifestyle program.[5]
The authors called their study small, single-site and short.[5] It also used one tested product. A different bottle could give a much smaller drop, or a larger one, because strength varies so widely between brands.[3]
The table below is our dose check. It sets what trials used next to what a 2017 lab test found in store-bought products.
Trial doses compared with what store products deliveredMeasureAmountWhat it tells you
Becker trial dose[5]1,800 mg twice daily (3,600 mg a day)The tested product lowered LDL at this amount
Safety meta-analysis dose groups[7]3 mg or less, 3.1 to 5 mg, over 5 mg monacolin K a dayTrials spanned a wide monacolin K range
US brands per 1,200 mg[3]0.09 to 5.48 mg monacolin KMore than a 60-fold spread
US brands per labeled daily serving[3]0.09 to 10.94 mg monacolin KMore than a 120-fold spread
Brands with no monacolin K[3]2 of 28Some bottles may do nothing for LDL

Is monacolin K the same as lovastatin, and what does the FDA say?
Yes. NCCIH states that monacolin K is structurally identical to lovastatin, the active drug in the prescription statin Mevacor.[1][2] Like other statins, it slows the body's own production of cholesterol.[1]
Because of this, products with enhanced or added lovastatin cannot be marketed as dietary supplements in the United States, because lovastatin was approved as a drug before it was sold as a food or supplement.[1] The FDA has sent warning letters to companies that sold such products.[1]
The FDA ingredient listing points to a 2007 lovastatin safety communication and to the court case Pharmanex v. Shalala, decided by a federal appeals court in 2000.[2] NCCIH sums up the result: products with considerable monacolin K are treated as unapproved new drugs and are not legal to sell in the US.[1]
So a product strong enough to match the trials may be one the FDA says should not be on the market, and a legal product may carry too little to matter.[1]
Why does red yeast rice strength vary so much between bottles?
Labels rarely state monacolin K, and lab tests show the amount ranges more than 60-fold between brands. In a 2017 test of 28 brands from mainstream US retailers, none listed monacolin K on the label. Two had none at all.[3]
The authors noted that FDA manufacturing standards had not produced consistent strength. They called the products "unpredictable."[3] NCCIH adds that some researchers have found commercial lovastatin added to products illegally.[1]
Contamination is a second problem. Citrinin is a toxin that some Monascus strains can make, and it can damage the kidneys. In a 2021 analysis of 37 products, only one had citrinin below the European Union limit, and four products labeled "citrinin-free" were contaminated.[1]
A "citrinin-free" line on the label does not settle the question. We explain how we weigh claims like this in how we review supplements.
What happened with the 2024 beni-koji recall in Japan?
In March 2024, red yeast rice tablets sold in Japan to lower cholesterol were linked to serious kidney injury, and about 2,600 people received medical care by late November 2024. About 540 of them needed a hospital stay.[9] The tablets came from Kobayashi Pharmaceutical, and the product named in research is Beni-koji Choleste-Help.[9][10]
The cause was not monacolin K or citrinin. Investigators found puberulic acid, an unexpected compound, in the tablets that made people ill.[9] They traced it to a different mold, Penicillium adametzioides, living in the production factory and growing on the rice culture.[9] A national survey of kidney doctors found that the implicated fungal strains did not produce citrinin.[8]
Of 192 patients in that survey, 94.1% had low kidney function when first seen. The pattern looked like Fanconi syndrome, a kind of damage to the kidney's filtering tubes.[8] Some lab values improved after people stopped the tablets, yet 87% still had reduced kidney function at the last check.[8] A 2026 lab study found that puberulic acid damages the energy centers of kidney tubule cells.[10]
What are the side effects of red yeast rice, and who should avoid it?
Because monacolin K is lovastatin, products with real amounts can cause the same problems as statins, including muscle, kidney and liver damage.[1] NCCIH also lists digestive upsets such as diarrhea, nausea and stomach pain.[1]
Reviews disagree on how often harm happens. A 2019 meta-analysis of 53 trials and 8,535 people found no rise in muscle problems.[7] The 2015 meta-analysis found liver and kidney injury in 0 to 5% of people, with no difference from control groups, but it rated the safety reporting in most trials as low quality.[4] In 2018 the European Food Safety Authority could not identify a guaranteed safe daily level of monacolins.[1]
For prescription statins, MedlinePlus says muscle damage is uncommon and can, in rare cases, lead to kidney damage. Statins may also raise type 2 diabetes risk in people already at high risk.[11]
Who should not take it

People who are pregnant or breastfeeding. There are no safety studies, and NCCIH does not recommend it.[1] Statins are also not used in pregnancy.[11]
Anyone already taking a statin. Red yeast rice can have the same drug interactions as statins, and doubling up adds the same type of drug twice.[1]
People who take medicines known to interact with statins. Ask a pharmacist, since grapefruit and some drugs change how the liver clears certain statins.[11]
People with kidney or liver disease should ask a doctor first, given the reported kidney and liver harms and the citrinin findings.[1]
Anyone who had muscle pain on a statin, unless a doctor is tracking it with blood tests.[5][11]

See a doctor promptly if you get unexplained muscle pain or weakness, or signs of liver or kidney trouble, while taking any cholesterol product.[1][11]
What do doctors use first for high LDL?
Statins are the most common medicine for high cholesterol, and doctors pick the drug and dose based on your LDL level, heart risk, age and other health problems.[12] Statins reduce how much cholesterol the liver makes and help the liver clear LDL already in the blood.[12]
When people cannot take statins, MedlinePlus lists other options. These include bile acid sequestrants and cholesterol absorption inhibitors. PCSK9 inhibitors are added for people at high risk or with familial hypercholesterolemia.[12]
A prescribed lovastatin tablet has a known dose and passes drug quality checks, which a red yeast rice capsule does not. No supplement replaces a prescribed medicine, and you should not stop a statin on your own.[11] MedlinePlus also notes that cholesterol medicines control cholesterol without curing it, so regular checks continue.[12] Our cholesterol and heart health guides cover diet and other first steps.
What should you check on a red yeast rice label?
Look for a stated monacolin K amount, independent contaminant testing and a clear serving size, then talk to your doctor before the first dose. Most US bottles in the 2017 test listed none of these.[3]

Is the monacolin K amount listed per serving? None of the 28 brands tested in 2017 listed it.[3]
Does the label say how much red yeast rice is in each serving, so you can compare it with the 1,800 mg twice daily used in the Becker trial?[5]
Is there a third-party test for citrinin? A "citrinin-free" line alone did not hold up in testing.[1]
Are you on a statin or any drug that interacts with statins? If yes, skip it.[1][11]
Will your doctor recheck your lipids and watch for muscle or liver signs? Plan that before you start.[11]
Is it a product linked to the 2024 Japan recall? Do not use recalled lots.[9]

If this applies to you, here is a sensible next stepYour situationNext step
You already take a statinDo not add red yeast rice; ask your doctor about dose or other drugs[1][12]
You stopped a statin because of muscle painAsk about a different statin or a non-statin drug first[11][12]
You are pregnant or breastfeedingAvoid it[1]
Your LDL is borderline and you want to try a supplementGet a baseline lipid test, choose a product that lists monacolin K, and recheck with your doctor[3][5]

Our editorial policy explains how we pick and update sources for pages like this one.
Bottom line
Red yeast rice can lower LDL because its active compound is lovastatin.[1][4] That same fact brings statin side effects and interactions, puts strong products in a legal gray zone, and labels rarely tell you how much you are getting.[1][3]
For most people a prescribed statin is the better first step, because the dose is known and the product is regulated. A person who cannot take statins is better served by asking a doctor about other prescription options than by guessing with a supplement of unknown strength.[5][12]

## Frequently asked questions

### Is red rice yeast the same as red yeast rice?

Yes. Both names describe rice fermented with Monascus mold, and people search both word orders. What changes between products is the amount of monacolin K, which ranged more than 60-fold across 28 US brands in a 2017 lab test.

### How long does red yeast rice take to lower cholesterol?

In the 2009 Annals of Internal Medicine trial, LDL was already 43 mg/dL lower at the 12-week check in people taking 1,800 mg twice daily. That trial also included a lifestyle program, so a lipid recheck after about three months with your doctor is reasonable.

### Can you take red yeast rice with a statin?

No. Monacolin K is the same molecule as lovastatin, so adding it to a statin stacks two doses of the same drug type. NCCIH notes it carries the same drug interactions and side effects as statins, including muscle and liver damage.

### Is red yeast rice legal in the United States?

Red yeast rice products without enhanced or added lovastatin are sold as supplements. The FDA says products with enhanced or added lovastatin cannot be marketed as supplements, and it treats products with considerable monacolin K as unapproved new drugs.

### Can red yeast rice damage your kidneys?

It can. NCCIH lists kidney damage among statin-type side effects, and only 1 of 37 tested products was below the EU limit for citrinin, a kidney toxin. In Japan in 2024, tablets contaminated with puberulic acid caused serious kidney injury.

## Sources

1. [Red Yeast Rice: What You Need To Know](https://www.nccih.nih.gov/health/red-yeast-rice). NCCIH, National Institutes of Health
2. [Information on Select Dietary Supplement Ingredients and Other Substances (red yeast rice entry)](https://web.archive.org/web/2026/https://www.fda.gov/food/dietary-supplements/information-select-dietary-supplement-ingredients-and-other-substances). US Food and Drug Administration, archived copy, entry dated 2024
3. [Variability in strength of red yeast rice supplements purchased from mainstream retailers](https://pubmed.ncbi.nlm.nih.gov/28641460/). Cohen et al., European Journal of Preventive Cardiology, 2017
4. [Red yeast rice results in significant LDL reduction but safety is uncertain: a systematic review and meta-analysis](https://pubmed.ncbi.nlm.nih.gov/25897793/). Gerards et al., Atherosclerosis, 2015
5. [Red yeast rice for dyslipidemia in statin-intolerant patients: a randomized trial](https://pubmed.ncbi.nlm.nih.gov/19528562/). Becker et al., Annals of Internal Medicine, 2009
6. [Effect of Xuezhikang, an extract from red yeast Chinese rice, on coronary events after myocardial infarction](https://pubmed.ncbi.nlm.nih.gov/18549841/). Lu et al., American Journal of Cardiology, 2008
7. [Safety of red yeast rice supplementation: a systematic review and meta-analysis of randomized controlled trials](https://pubmed.ncbi.nlm.nih.gov/30844537/). Fogacci et al., Pharmacological Research, 2019
8. [A nationwide questionnaire study evaluated kidney injury associated with Beni-koji tablets in Japan](https://pubmed.ncbi.nlm.nih.gov/39708997/). Shinzawa et al., Kidney International, 2025
9. [Mechanism of puberulic acid contamination in red yeast rice tablets that caused a serious food poisoning outbreak in Japan](https://pmc.ncbi.nlm.nih.gov/articles/PMC12332415/). Yoshinari et al., Proceedings of the Japan Academy Series B, 2025
10. [The pathophysiological mechanism of Beni-koji Choleste-Help or puberulic acid-induced kidney injury](https://pmc.ncbi.nlm.nih.gov/articles/PMC12925403/). Sekiguchi et al., Kidney International Reports, 2026
11. [Statins](https://medlineplus.gov/statins.html). MedlinePlus, National Library of Medicine
12. [Cholesterol Medicines](https://medlineplus.gov/cholesterolmedicines.html). MedlinePlus, National Library of Medicine

General information from JillLebofsky, not medical advice.