Clinofibrate (S-8527) is a hypelipidemic agent and a HMG-CoA reductase inhibitor. In Vivo: Clinofibrate administration (50 and 100 mg/kg/day, p.o.) significantly inhibits the increase in plasma fibrinogen level as well as serum- and VLDL-LDL-lipids^[1]. Clinofibrate significantly decreases the high plasma cholesterol level of atherosclerotic rats, which is 823±256 mg/dl, or about ten times that of control rats (85±11 mg/dl). On treatment with clinofibrate, the cholesterol level is reduced most in the very low density lipoprotein (VLDL) fraction^[2]. In rats which are refed either a fat-free diet or a 5% fat diet after a 2-day fast. clinofibrate at 30 mg/kg results in reductions of serum and liver triglyceride levels^[3]. Oral ingestion of S-8527 to normal rats for 7 days lowers serum triglycerides and cholesterol by about 27% at 1 mg/kg and 20% at 3 mg/kg, respectively. S-8527 at 3 mg/kg decreases liver triglyceride concentration by about 20%^[4].