Red Yeast Rice

Monascus purpureus · Monacolin K · Xuezhikang

Snapshot

Indications	Contraindications
Mild hypercholesterolemia¹ Total and LDL cholesterol lowering^{2, 3} LDL cholesterol in dyslipidemia⁴ Post-infarction coronary events⁵ Blood glucose⁶	Pregnancy or lactation⁶ Active liver disease⁷ Cholesterol-lowering medicines⁸

Red yeast rice is rice fermented with Monascus mold, which can enrich it with monacolin K, structurally identical to the medicine lovastatin and acting like a statin on cholesterol synthesis⁶. Use extends to coronary events after myocardial infarction and to blood glucose and pressure, where trials are fewer⁶.

Meta-analyses of randomized trials found lower total and LDL cholesterol than control^{2, 3}. Safety readings differ: a trial meta-analysis found no excess muscle disorders, while a 2018 European Food Safety Authority opinion found no guaranteed safe monacolin level⁶. A 2025 laboratory analysis of selected food supplements found monacolin K content did not match the manufacturer's declaration in any product tested⁹. Products are mostly capsules and tablets; see Form comparison.

Because monacolin K is lovastatin, muscle, liver, and kidney effects and drug interactions follow statin patterns⁶. Contamination is a separate hazard: citrinin can damage the kidneys⁶, and Japanese cases since 2024 involved kidney injury with Fanconi syndrome¹⁰.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

89 sources, 72 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources