Red yeast rice

What it is

Red yeast rice is produced when cooked rice is fermented with fungal strains of the genus Monascus. The rice turns deep red in the process. In East Asia, it has been used for more than a thousand years to color and season food and in traditional medicine. In Europe, it plays no role in normal foods; it is not authorized as a food coloring in the EU. Here it is known almost only as a capsule against high cholesterol.

During fermentation, the fungus forms a series of substances called monacolins. The most common is monacolin K. In its lactone form, it is identical to lovastatin, a statin approved in Germany as a prescription medicine. Red yeast rice is therefore not a gentle plant substance with a cholesterol-lowering side effect, but essentially a naturally formed statin in varying amounts, together with other monacolins and pigments whose effects are less well studied.

How it works

The mechanism is as well understood as for hardly any other supplement. In the liver, monacolin K inhibits the enzyme HMG-CoA reductase, the bottleneck of the body’s own cholesterol production. The liver cells then form more LDL receptors and remove more LDL cholesterol from the blood. That is exactly the route by which all statins work, and for statins it is well established that they prevent heart attacks and strokes.

Like lovastatin, monacolin K is broken down mainly via the liver enzyme CYP3A4. This explains why certain medications can raise its level sharply, and why the side effects resemble those of statins.

What users are looking for

Most people turn to red yeast rice because their cholesterol is slightly elevated and they do not want to take a medicine, or because they stopped statins due to muscle pain. Many report that their lab values fell markedly after a few weeks. That fits the study data and is not a placebo effect. The only important thing is what lies behind it: anyone taking red yeast rice is taking a statin without medical supervision and without a standardized dose.

What the studies show

The CCSPS study

4,870 patients after a heart attack received, double-blind, 0.6 g of Xuezhikang twice daily or placebo, for 4.5 years on average. According to the German expert commission of BVL and BfArM, this amount corresponds to 10 mg of lovastatin. The primary endpoint of non-fatal heart attack and coronary death occurred in 5.7 percent versus 10.4 percent, and all-cause mortality was 33 percent lower. The study is large and cleanly designed, but concerns a single Chinese product at a dose that is not allowed in the EU today.

The Gerards meta-analysis

The authors analyzed 20 randomized studies in which the monacolin K content was known. Red yeast rice lowered LDL by 1.02 mmol/l compared with placebo and was as effective as statins. Liver and kidney damage occurred in 0 to 5 percent, not more often than in the control groups. However, the authors emphasize that safety was methodologically poorly recorded in most studies.

The study in statin intolerance

43 adults who had stopped statins because of muscle pain received 2,400 mg of red yeast rice or 20 mg of pravastatin, each twice daily, for 12 weeks. 5 percent versus 9 percent dropped out because of muscle pain, and LDL fell by 30 versus 27 percent. The study is small, but shows that red yeast rice was not better tolerated here than a mild statin, but similarly.

Where the data stop

The strong data come from studies with amounts of monacolins that may no longer be sold in the EU today. Since 2022, daily portions must contain less than 3 mg of monacolins. For this amount there are hardly any stand-alone efficacy data, mostly only small, open studies with combination products, for example one with 40 people over 8 weeks in which LDL fell by 14.8 percent, but together with berberine and without a comparison group. What share the red yeast rice had in this cannot be said this way.

The reassuring safety data also have limits. A meta-analysis of 53 studies with 8,535 participants found no increased risk of muscle complaints. The German Federal Institute for Risk Assessment, however, considers this work unsuitable for dispelling the concerns because of substantial limitations, and the European Commission notes that small studies cannot capture rare serious side effects. In addition, the content of monacolins and by-products varies between products.

Status, approval and legal

In Germany, red yeast rice is currently allowed as a food supplement, but strictly limited. Under EU Regulation 2022/860, a daily portion must contain less than 3 mg of monacolins, and the packaging must state the content and warn against use during pregnancy and breastfeeding, under 18 and over 70 years of age, together with cholesterol-lowering agents and together with other red yeast rice products. From 5 mg of monacolin K per day, the expert commission of BVL and BfArM classifies a product as a medicine. The health claim on cholesterol lowering was deleted in 2024, so the effect may no longer be advertised. Since 2026, more has been in motion: on May 13, 2026, the member states approved a draft to ban monacolins from red yeast rice in foods entirely. Publication is expected for the end of 2026, after which existing products may still be sold for 12 months. Red yeast rice is not on the 2026 WADA Prohibited List.

Safety

The side effects correspond to those of lovastatin: muscle pain up to the rare, dangerous rhabdomyolysis, liver damage, and also complaints affecting nerves, the gastrointestinal tract and skin. EFSA describes individual cases of serious side effects from as little as 3 mg of monacolins per day and could not set a safe daily amount in 2018 and again in 2025. The BfR therefore advises against consumption or only after consulting a physician. Interactions threaten with drugs that inhibit the enzyme CYP3A4, for example certain antifungals, HIV medications and ciclosporin, as well as with fibrates and high-dose niacin. Contaminants are a risk of their own: the mycotoxin citrinin can damage the kidneys; its maximum level was lowered to 100 µg/kg in 2020. In Japan in 2024, contaminated batches of a red yeast rice product led to kidney damage; 2,628 people sought medical help, and 76 possibly related deaths were reported. The cause there was contamination with another mold, not the monacolin.

Sources

• Commission Regulation (EU) 2022/860 – monacolins from red yeast rice
• EFSA ANS Panel, EFSA Journal 2018 – safety of monacolins in red yeast rice
• EFSA NDA Panel, EFSA Journal 2025 – additional data on the safety of monacolins
• BfR Opinion No 003/2020 – food supplements with red yeast rice
• Joint expert commission BVL/BfArM – classification of red yeast rice products
• Gerards et al., Atherosclerosis 2015 – meta-analysis on LDL and safety
• Lu et al., Am J Cardiol 2008 – Xuezhikang after myocardial infarction (CCSPS)
• Fogacci et al., Pharmacol Res 2019 – meta-analysis on safety
• Halbert et al., Am J Cardiol 2010 – red yeast rice versus pravastatin in statin intolerance
• Chikasue et al., Am J Kidney Dis 2025 – kidney damage from a Japanese red yeast rice product