Home Ingredients Red Yeast Rice (Monascus purpureus)

Red Yeast Rice (Monascus purpureus)

Monascus purpureus
Evidence Level
Strong
4 Clinical Trials
3 Documented Benefits
4/5 Evidence Score

Red yeast rice is rice fermented with the red yeast fungus Monascus purpureus. Fermentation produces monacolins; the main one, monacolin K, is chemically identical to lovastatin, a prescription cholesterol medicine ingredient. In placebo-controlled trials, red yeast rice lowered LDL cholesterol, a blood lipid marker. The US FDA treats products with enhanced or added lovastatin, or high monacolin K content, as unapproved new drugs. Testing found monacolin K varying more than 60-fold between US brands and absent from some, and some products contained citrinin, a contaminant that can damage the kidneys. EFSA could not identify a monacolin intake free of health concern, and the EU limits a daily portion to under 3 mg of monacolins. It can cause statin-type muscle and liver effects and drug interactions; do not combine it with a statin or use it in pregnancy or breastfeeding.

Studied Dose Trials used 2.4 g/day of a proprietary product, 1,800 mg twice daily, or a product standardized to 5 mg monacolins per day. Monacolin K per serving varies widely between brands and is often unlabeled; the EU limits a daily portion to less than 3 mg of monacolins.
Active Compound Monacolin K (in lactone form chemically identical to lovastatin) plus other monacolins produced by Monascus fermentation

Benefits

Lower LDL cholesterol versus placebo

In randomized placebo-controlled trials in adults with raised cholesterol, red yeast rice lowered LDL cholesterol more than placebo. A meta-analysis of 13 placebo-controlled trials (804 participants) found an average LDL reduction of 0.87 mmol/L. LDL is a blood marker, and the effect depends on monacolin K content, which varies widely between products.

Supported by Trial 4, Trial 1

LDL cholesterol over 24 weeks with a lifestyle program

In a 24-week randomized trial of 62 adults who had stopped statins because of muscle aches, red yeast rice (1,800 mg twice daily) plus a lifestyle program lowered LDL cholesterol more than placebo plus the same program. Pain scores and creatine kinase did not differ between groups. The trial was small, single-site and short.

Supported by Trial 2

Total cholesterol and triglyceride lowering

In a 12-week placebo-controlled trial in 83 US adults on a lower-fat diet, red yeast rice (2.4 g/day) lowered total cholesterol, LDL cholesterol and triglycerides more than placebo, while HDL cholesterol did not change. A meta-analysis of placebo-controlled trials also found lower triglycerides but no significant HDL change.

Supported by Trial 1, Trial 2

Mechanism of action

1

HMG-CoA reductase inhibition

Monacolin K in lactone form is identical to lovastatin and acts by inhibiting HMG-CoA reductase, an enzyme in the liver's cholesterol synthesis pathway.

2

Other monacolins

Red yeast rice contains 14 monacolins that inhibit cholesterol synthesis. In one analysis of 12 products, monacolin KA ranged from 0.00 to 2.30 mg per capsule alongside monacolin K, so total monacolin content differs from monacolin K alone.

3

Variable standardization

Monacolin K ranged from 0.10 to 10.09 mg per capsule across 12 products in one analysis. In 28 US brands, it was absent from 2 and ranged more than 60-fold (0.09 to 5.48 mg per 1,200 mg) in the rest, so the dose a consumer takes is unpredictable.

4

Citrinin contamination

Some Monascus strains can produce citrinin, a mycotoxin that can damage the kidneys. Four of 12 tested products had elevated citrinin. NCCIH reports that in a 37-product analysis only one product had citrinin below the EU maximum, and four contaminated products were labeled citrinin-free.

Clinical trials

1
Proprietary red yeast rice supplement vs placebo in US adults
PubMed

Randomized, double-blind, placebo-controlled 12-week trial of 2.4 g/day with a lower-fat diet; the abstract describes a proprietary Chinese product and does not name the supplier; PubMed lists US Public Health Service and non-government support, and maker funding could not be checked (Heber et al. 1999, Am J Clin Nutr)

83 adults (46 men, 37 women, aged 34 to 78) with raised cholesterol, not taking lipid-lowering drugs.

Total cholesterol fell from 254 to 208 mg/dL by week 8 on red yeast rice, a significant difference from placebo (P < 0.001). LDL cholesterol and triglycerides were also lower than placebo; HDL cholesterol did not change significantly.

2
Red yeast rice vs placebo in adults who had stopped statins
PubMed

Randomized controlled trial, 1,800 mg twice daily or placebo for 24 weeks, with a 12-week lifestyle program in both groups; single community cardiology practice, NIH and non-government support listed (Becker et al. 2009, Ann Intern Med)

62 adults with dyslipidemia who had stopped statins because of muscle aches.

LDL cholesterol (primary outcome) fell by 43 mg/dL at week 12 and 35 mg/dL at week 24 on red yeast rice vs 11 and 15 mg/dL on placebo, significantly lower at both time points. HDL, triglycerides, liver enzymes, creatine kinase, weight and pain scores did not differ between groups.

3
Red yeast rice vs phytosterols vs both for 8 weeks
PubMed

Three-arm, double-blind randomized trial; red yeast rice standardized to 5 mg monacolins per day compared with phytosterols 800 mg (active control, no placebo arm); funded by University of Bologna institutional funds and the authors declared no competing interests (Cicero et al. 2017, Nutr Metab (Lond))

90 adults with moderately raised cholesterol.

LDL cholesterol fell 20.5% from baseline on red yeast rice, a significantly larger change than on phytosterols alone, which produced no significant lipid change. The combination lowered LDL more than red yeast rice alone.

4
Xuezhikang extract vs placebo after a previous myocardial infarction
PubMed

Randomized, placebo-controlled multicenter trial for an average of 4.5 years of Xuezhikang, a partially purified red yeast rice extract and a different product from consumer red yeast rice supplements; a treatment result in people with established disease (Lu et al. 2008, Am J Cardiol)

Nearly 5,000 Chinese adults with a previous myocardial infarction and average LDL cholesterol at baseline.

The primary end point (nonfatal myocardial infarction or coronary death) occurred in 5.7% on Xuezhikang vs 10.4% on placebo. Cardiovascular and total mortality were 30% and 33% lower, and total and LDL cholesterol were lower.

Side effects and drug interactions

Common Potential side effects

Muscle pain and raised creatine kinase, and less often rhabdomyolysis, have been reported to adverse event surveillance systems; EFSA concluded monacolin K from red yeast rice can cause severe muscle and liver effects, with severe cases reported at intakes as low as 3 mg per day.
Liver injury has been reported (10 of 55 reactions in an Italian surveillance series).
Digestive problems such as diarrhea, nausea and stomach pain.
Skin reactions (9 of 55 reactions in an Italian surveillance series).
Citrinin, a contaminant that can damage the kidneys, has been found in some products, including some labeled citrinin-free.
No studies cover pregnancy or breastfeeding; NCCIH advises against use, and EU labels must state it should not be used by pregnant or breastfeeding women, people under 18 or adults over 70.
A meta-analysis of 53 randomized trials found no increase in muscle complaints versus control, but another review judged safety assessment in most trials to be of low quality.

Important Drug interactions

Statins and other cholesterol-lowering medicines: do not combine; FDA lists other cholesterol-lowering medications among drugs that raise the risk of muscle reactions with lovastatin.
Azole antifungals (itraconazole, ketoconazole), macrolide antibiotics (erythromycin, clarithromycin), HIV protease inhibitors and nefazodone: strong CYP3A4 inhibitors that raise lovastatin levels and muscle risk.
Grapefruit juice: a CYP3A4 inhibitor that can raise blood levels of lovastatin; avoid taking it with red yeast rice.
Cyclosporine: an interaction was suspected when a kidney transplant patient taking cyclosporine developed rhabdomyolysis several months after starting red yeast rice.
Gemfibrozil: raised the blood level of lovastatin acid from a red yeast rice extract in a 14-volunteer study.
Verapamil and amiodarone: listed as contraindicated with lovastatin in EU product information.

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Frequently asked questions about Red Yeast Rice (Monascus purpureus)

What is Red Yeast Rice used for?

Red yeast rice is taken as a dietary supplement for blood cholesterol. In placebo-controlled trials in adults with raised cholesterol, it lowered LDL cholesterol, a blood marker; the effect comes from its monacolin K. How much monacolin K a product contains varies widely and is usually not on the label.

How is monacolin K related to lovastatin?

Monacolin K in lactone form is chemically identical to lovastatin, a prescription drug ingredient. For that reason the US FDA treats red yeast rice products with enhanced or added lovastatin, or high monacolin K content, as unapproved new drugs, and products with meaningful monacolin K carry the same kinds of muscle and liver risks and drug interactions as statins.

What is the recommended dosage of Red Yeast Rice?

There is no established recommended dose. Trials used 2.4 g/day of one proprietary product, 1,800 mg twice daily, or a product standardized to 5 mg monacolins per day. US product testing found monacolin K varying more than 60-fold between brands. The EU limits a daily portion to less than 3 mg of monacolins, and EFSA could not identify an intake that raises no health concern.

Is Red Yeast Rice safe, and does it have side effects?

It has statin-type risks. Muscle pain, raised creatine kinase, rare rhabdomyolysis and liver injury have been reported, and EFSA noted severe reactions at intakes as low as 3 mg of monacolins per day. Some products contain citrinin, which can damage the kidneys. Do not combine it with a statin, CYP3A4-inhibiting drugs or grapefruit juice, and do not use it in pregnancy or breastfeeding. Talk with your doctor before use.

Has red yeast rice been tested for heart outcomes?

The one outcome trial cited here tested Xuezhikang, a partially purified red yeast rice extract, against placebo in nearly 5,000 Chinese adults who had already had a myocardial infarction, and reported fewer coronary events over about 4.5 years. That was a different, standardized product used as treatment in people with established disease, so it does not show what consumer red yeast rice supplements do. The supplement-type trials cited here measured blood lipids, not heart events.

What is Red Yeast Rice?

Red yeast rice is rice fermented with the red yeast fungus Monascus purpureus. Fermentation produces monacolins; the main one, monacolin K, is chemically identical to lovastatin, a prescription cholesterol medicine ingredient. In placebo-controlled trials, red yeast rice lowered LDL cholesterol, a blood lipid marker.

Does Red Yeast Rice interact with any medications?

Possible interactions include: Statins and other cholesterol-lowering medicines: do not combine; FDA lists other cholesterol-lowering medications among drugs that raise the risk of muscle reactions with lovastatin. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Red Yeast Rice?

NutraSmarts rates the evidence for Red Yeast Rice as Strong (4 out of 5). It is backed by 4 study summaries and 14 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(14 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Becker DJ, Gordon RY, Halbert SC, French B, Morris PB, Rader DJ. Red yeast rice for dyslipidemia in statin-intolerant patients: a randomized trial. Ann Intern Med. 2009;150(12):830-9, W147-9. doi: 10.7326/0003-4819-150-12-200906160-00006.PubMedUsed to support: Randomized controlled trial in 62 adults with dyslipidemia who had stopped statins because of muscle aches: red yeast rice 1,800 mg twice daily plus a 12-week lifestyle program lowered LDL cholesterol (primary outcome) and total cholesterol more than placebo at weeks 12 and 24. HDL, triglycerides, liver enzymes, creatine kinase, weight and pain scores did not differ. Small, single-site and short.
  2. Gerards MC, Terlou RJ, Yu H, Koks CH, Gerdes VE. Traditional Chinese lipid-lowering agent red yeast rice results in significant LDL reduction but safety is uncertain - a systematic review and meta-analysis. Atherosclerosis. 2015;240(2):415-23. doi: 10.1016/j.atherosclerosis.2015.04.004.PubMedUsed to support: Systematic review and meta-analysis of 20 randomized studies of red yeast rice with known monacolin K content: LDL cholesterol fell by 1.02 mmol/L versus placebo. Quality of safety assessment was low in most studies; reported liver and kidney injury (0 to 5%) did not differ from control groups.
  3. Li Y, Jiang L, Jia Z, Xin W, Yang S, Yang Q, Wang L. A meta-analysis of red yeast rice: an effective and relatively safe alternative approach for dyslipidemia. PLoS One. 2014;9(6):e98611. doi: 10.1371/journal.pone.0098611.PubMedUsed to support: Meta-analysis of 13 randomized placebo-controlled trials (804 participants; Xuezhikang and Zhibituo excluded): red yeast rice lowered total cholesterol, LDL cholesterol (by 0.87 mmol/L) and triglycerides versus placebo, with no significant HDL change. No serious side effects were reported; the authors called for longer, rigorous trials.
  4. Cohen PA, Avula B, Khan IA. Variability in strength of red yeast rice supplements purchased from mainstream retailers. Eur J Prev Cardiol. 2017;24(13):1431-1434. doi: 10.1177/2047487317715714.PubMedUsed to support: Analysis of 28 US red yeast rice brands: monacolin K was not detected in 2, and in the other 26 it ranged more than 60-fold, from 0.09 to 5.48 mg per 1,200 mg; at labeled daily servings intake would range from 0.09 to 10.94 mg per day.
  5. Lu Z, Kou W, Du B, Wu Y, Zhao S, Brusco OA, Morgan JM, Capuzzi DM, Chinese Coronary Secondary Prevention Study Group, Li S. Effect of Xuezhikang, an extract from red yeast Chinese rice, on coronary events in a Chinese population with previous myocardial infarction. Am J Cardiol. 2008;101(12):1689-93. doi: 10.1016/j.amjcard.2008.02.056.PubMedUsed to support: Randomized placebo-controlled multicenter trial of Xuezhikang, a partially purified red yeast rice extract, in nearly 5,000 Chinese adults with a previous myocardial infarction, for an average of 4.5 years. Major coronary events were 5.7% vs 10.4% on placebo, and cardiovascular and total mortality were 30% and 33% lower. This is a different, standardized product studied as treatment in established disease, not a consumer supplement.
  6. Heber D, Yip I, Ashley JM, Elashoff DA, Elashoff RM, Go VL. Cholesterol-lowering effects of a proprietary Chinese red-yeast-rice dietary supplement. Am J Clin Nutr. 1999;69(2):231-6. doi: 10.1093/ajcn/69.2.231.PubMedUsed to support: Randomized double-blind placebo-controlled 12-week trial in 83 US adults with raised cholesterol on a lower-fat diet: red yeast rice 2.4 g/day lowered total cholesterol, LDL cholesterol and triglycerides versus placebo; HDL did not change. The abstract does not name the supplier or state maker funding.
  7. Cicero AFG, Fogacci F, Rosticci M, Parini A, Giovannini M, Veronesi M, D'Addato S, Borghi C. Effect of a short-term dietary supplementation with phytosterols, red yeast rice or both on lipid pattern in moderately hypercholesterolemic subjects: a three-arm, double-blind, randomized clinical trial. Nutr Metab (Lond). 2017;14:61. doi: 10.1186/s12986-017-0214-2.PubMedUsed to support: Three-arm double-blind trial in 90 adults with moderately raised cholesterol: red yeast rice standardized to 5 mg monacolins lowered LDL cholesterol 20.5% from baseline over 8 weeks, significantly more than phytosterols alone (no placebo arm). Authors declared no competing interests.
  8. Gordon RY, Cooperman T, Obermeyer W, Becker DJ. Marked variability of monacolin levels in commercial red yeast rice products: buyer beware! Arch Intern Med. 2010;170(19):1722-7. doi: 10.1001/archinternmed.2010.382.PubMedUsed to support: Analysis of 12 red yeast rice products each labeled 600 mg per capsule: monacolin K ranged from 0.10 to 10.09 mg per capsule and total monacolins from 0.31 to 11.15 mg; 4 products had elevated citrinin, a mycotoxin nephrotoxic in animals.
  9. Mazzanti G, Moro PA, Raschi E, Da Cas R, Menniti-Ippolito F. Adverse reactions to dietary supplements containing red yeast rice: assessment of cases from the Italian surveillance system. Br J Clin Pharmacol. 2017;83(4):894-908. doi: 10.1111/bcp.13171.PubMedUsed to support: Italian surveillance reports, 2002 to 2015: 55 suspected reactions to red yeast rice supplements, including myalgia or raised creatine kinase (19), rhabdomyolysis (1), liver injury (10), digestive (12) and skin reactions (9); 13 required hospitalization. The authors suggest the safety profile resembles that of statins.
  10. Fogacci F, Banach M, Mikhailidis DP, Bruckert E, Toth PP, Watts GF, Reiner Ž, Mancini J, Rizzo M, Mitchenko O, Pella D, Fras Z, Sahebkar A, Vrablik M, Cicero AFG, Lipid and Blood Pressure Meta-analysis Collaboration (LBPMC) Group, International Lipid Expert Panel (ILEP). Safety of red yeast rice supplementation: A systematic review and meta-analysis of randomized controlled trials. Pharmacol Res. 2019;143:1-16. doi: 10.1016/j.phrs.2019.02.028.PubMedUsed to support: Meta-analysis of safety data from 53 randomized trials (8,535 participants): red yeast rice was not associated with more musculoskeletal adverse events than control (OR 0.94, 95% CI 0.53 to 1.65), the primary outcome; non-musculoskeletal and serious adverse events were less frequent than in controls. Randomized trials of this size cannot detect rare reactions such as those seen in surveillance reports.
  11. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS), Younes M, Aggett P, Aguilar F, Crebelli R, Dusemund B, Filipič M, Frutos MJ, Galtier P, Gott D, Gundert-Remy U, Kuhnle GG, Lambré C, Leblanc JC, Lillegaard IT, Moldeus P, Mortensen A, Oskarsson A, Stankovic I, Waalkens-Berendsen I, Woutersen RA, Andrade RJ, Fortes C, Mosesso P, Restani P, Pizzo F, Smeraldi C, Wright M. Scientific opinion on the safety of monacolins in red yeast rice. EFSA J. 2018;16(8):e05368. doi: 10.2903/j.efsa.2018.5368.PubMedUsed to support: EFSA safety opinion: monacolin K in lactone form is identical to lovastatin; supplement intakes can reach the therapeutic lovastatin range; significant safety concern at 10 mg/day, with severe reactions reported at intakes as low as 3 mg/day affecting muscle (including rhabdomyolysis) and liver. The Panel could not identify an intake of monacolins that raises no health concern. Also discusses CYP3A4 interactions (grapefruit juice, cyclosporine, gemfibrozil) and lovastatin product warnings for pregnancy.
  12. EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA), Turck D, Bohn T, Cámara M, Castenmiller J, De Henauw S, Hirsch-Ernst KI, Jos Á, Mangelsdorf I, McNulty B, Naska A, Pentieva K, Siani A, Thies F, Matijević L, Martinez SV, Maciuk A. Scientific Opinion on additional scientific data related to the safety of monacolins from red yeast rice submitted pursuant to Article 8(4) of Regulation (EC) No 1925/2006. EFSA J. 2025;23(2):e9276. doi: 10.2903/j.efsa.2025.9276.PubMedUsed to support: EFSA 2025 opinion: restates that Commission Regulation (EU) 2022/860 limits a daily portion of food supplements to less than 3 mg of monacolins from red yeast rice and requires a label stating it should not be consumed by pregnant or lactating women, people under 18 or adults over 70. New data did not establish safety below 3 mg/day or identify an intake that raises no concern.
  13. National Center for Complementary and Integrative Health (NCCIH). Red Yeast Rice NCCIH Health Information (not PubMed-indexed). 2022;Last updated November 2022; accessed 2026. https://www.nccih.nih.gov/health/red-yeast-rice.SourceUsed to support: Not PubMed-indexed (US NIH fact sheet). States that the FDA considers red yeast rice products with enhanced or added lovastatin, or high monacolin content, unapproved new drugs; that monacolin K content cannot be known by consumers; that some products contain citrinin, which can damage the kidneys; that products with meaningful monacolin K can cause statin-type side effects and interactions plus digestive problems; and advises against use in pregnancy or breastfeeding.
  14. U.S. Food and Drug Administration. Avoid Red Yeast Rice Promoted for High Cholesterol FDA Consumer Update (archived, not PubMed-indexed). 2007;Posted August 10, 2007. Archived at https://web.archive.org/web/20090118050644/http://www.fda.gov/consumer/updates/redyeastrice081007.html.SourceUsed to support: Not PubMed-indexed (FDA consumer update, read via web archive). FDA warned consumers not to buy three red yeast rice products sold online after FDA testing found lovastatin in them; FDA warning letters called them unapproved new drugs. Lovastatin can cause severe muscle problems leading to kidney impairment, with greater risk at higher doses or with nefazodone, certain antibiotics, antifungal and HIV drugs, and other cholesterol-lowering medications.