Y-9738 is a hypolipidemic agent. At 100 mg/kg Y-9738 lowers the cholesterol level by 36% and clearly diminishes the intensity of the β-lipoprotein band with a tendency for the α-lipoprotein band to be intensified. Y-9738 causes a dose-dependent decrease in serum cholesterol, triglyceride and heparin-precipitable β-lipoprotein cholesterol. Furthermore, Y-9738 reduces the intensity of the β-lipoprotein band shown by electrophoresis, and increases that of the α-lipoprotein band.