Comet XR 500 is a medicine used to treat type 2 diabetes mellitus. It helps control blood sugar levels and thus prevent serious complications of diabetes. It is also used to treat menstruation related disorder known as Polycystic ovary syndrome (PCOS) in women. Comet XR 500 is best taken with food to avoid nausea and abdominal pain. You should take it regularly, at the same time each day, to get the most benefit. You should not stop taking this medicine unless your doctor recommends it. Your lifestyle plays a big part in controlling diabetes. Therefore, it is important to stay on the diet and exercise program recommended by your doctor while taking this medicine. The most common side effects of this medicine include nausea, vomiting, taste change, diarrhea, abdominal pain and loss of appetite. Some people may develop hypoglycemia (low blood sugar level) when this medicine is taken along with other antidiabetic medicines, alcohol or upon skipping a meal. Monitor your blood sugar levels regularly while taking it. Before taking this medicine, inform your doctor if you have any kidney, liver or heart problems. Pregnant or breastfeeding women should also consult their doctor before taking it. Your doctor will check your kidney function tests before starting treatment with it. Avoid excessive alcohol intake while taking it as this may increase the risk of developing some side effects.