A lipid-regulating agent that lowers elevated serum lipids primarily by decreasing serum triglycerides with a variable reduction in total cholesterol. These decreases occur primarily in the VLDL fraction and less frequently in the LDL fraction. Gen-Fibro increases HDL subfractions HDL2 and HDL3 as well as apolipoproteins A-I and A-II. Its mechanism of action has not been definitely established. .