What is red yeast rice?

Red yeast rice (RYR) is a fermented rice with a long history of use as a food and medicine in East Asia.^[1] RYR is produced by fermenting white rice (Oryza sativa) with an edible fungus, most commonly Monascus purpureus, which results in the production of a variety of bioactive compounds and pigments, the latter of which imparts a reddish-purple color to the rice.^[2] The primary active compound in RYR is thought to be monacolin K, which is structurally identical to the cholesterol-lowering medication lovastatin.^[2] However, the type and amount of monacolins present in RYR can vary depending on the fermentation conditions and the type of yeast used.^[3] The majority of research on RYR has examined its effects on dyslipidemia and general cardiovascular health, with promising results.