Crestor 5mg is used to correct the levels of fatty substances in the blood called lipids, the most common of which is cholesterols. There are different types of cholesterol found in the blood ? ?bad? cholesterol (LDL-C) and ?good? cholesterol (HDL-C). Crestor can reduce the ?bad? cholesterol and increase the ?good? cholesterol. It works by helping to block your body?s production of ?bad? cholesterol. It also improves your body?s ability to remove it from your blood.