Crestor tablets contain the active ingredient rosuvastatin calcium which is used to lower cholesterol, triglycerides, and fatty deposits in blood vessels to reduce the risk of heart attack, stroke, and other heart complications. It is taken once daily with or without food and comes in doses of 5, 10, 20, or 40 mg depending on the condition being treated. Side effects can include headache, abdominal pain, and nausea while more serious effects like muscle damage require immediate medical attention.