Pirinixil is a hypolipidemic agent of low toxicity. Total cholesterol is reduced by Pirinixi in the spleen, kidney and heart of rats. Pirinixil decreases the estimated total body cholesterol approximately 40%. Pirinixil increases plasma cholesterol levels significantly without affecting plasma triglycerides. Liver cholesterol and triglycerides are markedly reduced by Pirinixil, while combined plasma and liver lipid levels decrease approximately 20%. Liver HMG-CoA reductase activity is not affected, but cholesterol 7α-hydroxylase is significantly reduced by Pirinixil.