This was a randomized, parallel, and placebo-controlled study. Forty subjects were divided into a test group and a placebo group. The study was focused on the potential effects of a mixture of Schisandra fruit extract and sesamin (hereinafter called ‘SCH’) in the subjects with borderline high levels (40–60 U/L) of alanine aminotransferase (ALT) or aspartate aminotransferase (AST). Twenty subjects taking SCH (four tablets per day) and 20 subjects taking a placebo (four tablets per day) were studied. The effects of SCH on ALT, AST, total bilirubin, direct bilirubin, free radical levels, total antioxidant status, glutathione peroxidase, glutathione reductase, and the lag time for low-density lipoprotein oxidation were determined. The total test period was 5 months. Intervention of SCH clearly reduced the levels of ALT and AST, but it made no change in the total bilirubin and direct bilirubin. Intake of SCH also greatly increased the antioxidant capacity and decreased the values of thiobarbituric acid reactive substances, total free radicals, and superoxide anion radicals in the plasma. The activities of glutathione peroxidase and reductase in the erythrocytes were significantly increased. In addition, the lag time for low-density lipoprotein oxidation, an inflammatory marker, was evidently increased. Fatty liver was found to have been significantly improved in this study. SCH proved to have the effects of antioxidation and improving liver function. Copyright © 2012 John Wiley & Sons, Ltd.