Rosiglitazone is an oral medication used to lower blood sugar, often prescribed alongside other oral hypoglycemic drugs like metformin or a sulphonylurea, for the treatment of type 2 diabetes. The drug works by decreasing insulin resistance in the body’s peripheral tissues. Possible side effects of rosiglitazone can include digestive issues, weight gain, and anemia, which is characterized by a lowered level of the oxygen-carrying component, hemoglobin, in the blood.