Administration alone or with HMG-CoA reductase inhibitors as adjunctive therapy to diet for reduction of elevated total cholesterol, low density lipoprotein cholesterol (LDL), and apolipoprotein in patients with primary hypercholesterolemia; with atorvastatin or simvastatin for the reduction of elevated total cholesterol and LDL levels in patients with homozygous familial hypercholesterolemia as an adjunct to other lipid-lowering treatments or if such treatments are unavailable; as adjunctive therapy to diet for the reduction of elevated sitosterol and campesterol levels in patients with homozygous familial sitosterolemia.