Crestat 20mg tablets contain the active ingredient Rosuvastatin, which belongs to a group of medicines known as statins. It is used to lower cholesterol levels in the blood and reduce the risk of heart disease and stroke. Rosuvastatin works by blocking an enzyme in the liver that is responsible for producing cholesterol. By reducing cholesterol production, it can lower the amount of cholesterol that builds up in the walls of arteries, reducing the risk of blockages that can lead to heart attacks and strokes.