Variability in strength of red yeast rice supplements purchased from mainstream retailers

Abstract

The United States Food and Drug Administration (FDA) has introduced manufacturing standards for dietary supplements, including red yeast rice, to assure their identity, purity, strength, and composition. One supplement commonly used to self-treat high cholesterol, red yeast rice, may contain monacolin K, an ingredient identical to prescription lovastatin. We examined whether FDA's manufacturing standards led to standard concentrations of the statin monacolin K in red yeast rice supplements. We analyzed 28 brands of red yeast rice supplements by ultra-high performance liquid chromatography-diode array detector-quadrupole time-of-flight mass spectrometry for monacolin K content. Monacolin K was not detected in two brands. In the 26 brands that contained monacolin K, the quantity ranged more than 60-fold from 0.09 to 5.48 mg per 1200 mg of red yeast rice. Following the manufacturers' recommendations for daily servings, the quantity of monacolin K consumed per day would range more than 120-fold from 0.09 to 10.94 mg. Despite FDA manufacturing standards, strength and composition of red yeast rice supplements sold at mainstream retail stores in the United States remains unpredictable.

<p>Evaluating Risk of Incident Diabetes Between Patients Who Used Lovastatin and Red Yeast Rice Prescriptions (LipoCol Forte): A Retrospective Cohort Study Based on a Real-World Database</p>

“…In addition, it is also not easy to predict or understand the side effect risks of RYR because of the high variability in monacolin content in various commercial RYR dietary supplements. [36][37][38] Unlike the dietary supplement, it was suggested that the content of RYR prescriptions with good manufacturing practice were relatively stable and safe, such as Xuezhikang, HypoCol, and LipoCol Forte. [13][14][15]29 A clinical trial suggested that there were no differences between the HypoCol group and the placebo group with regard to glucose tolerance.…”

Acute liver injury induced by red yeast rice supplement

“…These effects are difficult to pre-empt, in part because the concentration of monacolin K in red yeast rice is not regulated. A recent study performed in the USA found that monacolin K concentrations ranged from 0.09 to 10.94 mg per daily manufacturer recommended dose 1. Of note, 5–7 mg of monacolin is as effective as 20–40 mg of pure lovastatin 3.…”

“…Red yeast rice is a supplement made by fermenting steamed rice with a food fungus, M purpureus (Aspergillaceae family), and is frequently used to lower low density lipoprotein as an alternative to statins. Unbeknownst to most physicians and patients, it contains monacolin K, a fungal product which is biochemically equivalent to lovastatin, and hence carries the same risk of hepatotoxicity 1. Physicians and patients should be made aware that red yeast rice is not a harmless supplement, and those choosing to use it should watch for symptoms of hepatotoxicity.…”

Editor’s presentation

“…5 This large variation may introduce large differences in the lipid-lowering effects within and between individuals, and raise questions as to the effectiveness and the safety of these supplements. Furthermore, given that RYR supplements may contain prescriptionlevel doses of statins, these supplements may pose risks to consumers similar to those of prescription statins.…”