Some red yeast rice products contain substantial amounts of monacolin K, which is chemically identical to the active ingredient in the cholesterol-lowering drug lovastatin. These products may lower blood cholesterol levels and can cause the same types of side effects and drug interactions as lovastatin.

Other red yeast rice products contain little or no monacolin K. It is not known whether these products have any effect on blood cholesterol levels.

Some red yeast rice products contain a contaminant called citrinin, which can cause kidney failure.  In a 2011 analysis of red yeast rice products sold as dietary supplements, 4 of 11 products were found to contain this contaminant.

via Red Yeast Rice: An Introduction | NCCAM.

Personally, I’m sticking with a statin.