Cholesterol levels at 240 milligrams per deciliter for the total cholesterol and 130 milligrams per deciliter for low-density lipoprotein cholesterol require statins, states Mayo Clinic. Statins help to lower the blood's bad cholesterol by preventing its formation.
High cholesterol affects the cardiovascular system and may cause stroke or a heart attack, states WebMD. Lifestyle changes such as exercise and a healthy diet help to reduce LDL cholesterol by up to 30 percent. Statins, however, have a much more significant effect on cholesterol levels, reducing bad cholesterol by 50 percent while boosting HDL cholesterol by up to 15 percent, and the effects occur within weeks.