Gemfibrozil belongs to the class of medications called fibrates. Fibrates work speeding the natural processes that remove cholesterol from the body. They lower the amount of 'bad cholesterol' (low density lipoprotein or LDL-cholesterol) and 'fat' (triglyceride) as well as increase the amount of 'good cholesterol' (high density lipoprotein or HDL-cholesterol) in the blood.
High 'bad cholesterol' levels can cause your blood vessels to clog up and lead to chest pain (angina), heart attack or stroke. Hence, this medication may reduce your risk for heart attack and stroke.