Metformin is a first-line treatment used for type 2 diabetes in adults and children 10 years and older to help improve blood sugar levels. It is also used off-label to improve symptoms of polycystic ovarian syndrome (PCOS) and other conditions. Metformin hydrochloride (1,1-dimethylbiguanide hydrochloride) is freely soluble in water, slightly soluble in ethanol, but almost insoluble in acetone, ether, or chloroform. Metformin hydrochloride, the medicine in metformin hydrochloride tablets, can cause a rare, but serious, side effect called lactic acidosis (a build-up of lactic acid in the blood) that can cause death. Overview: Metformin is medicine you take to help keep your blood sugar from getting too high. Common side effects may include stomach problems, such as diarrhea, nausea, vomiting, stomach pain. Metformin is a generic prescription medication used to help manage blood sugar levels in adults and some children with type 2 diabetes. It works by decreasing sugar production in the liver. Metformin is a biguanide antihyperglycemic agent used for treating non-insulin-dependent diabetes mellitus (NIDDM). It improves glycemic control by decreasing hepatic glucose production, decreasing glucose absorption and increasing insulin-mediated glucose uptake. Metformin is used together with proper diet and exercise to treat high blood sugar levels caused by type 2 diabetes. This medicine reduces the absorption of sugar from the intestines, reduces the release of stored sugar from the liver, and helps your body use sugar better. This article describes the dosages of metformin, as well as its strengths and how to take it. When taking metformin, always follow the dosage prescribed by your doctor. Metformin helps manage blood sugar in type 2 diabetes. WebMD reviews common side effects, extended-release benefits, vitamin B12 risks, and precautions. Easy-to-read patient tips for metformin covering how it works, benefits, risks, and best practices.