Diabetes means your blood glucose, or blood sugar, levels are too high. If you can't control your diabetes with wise food choices and physical activity, you may need diabetes medicines. The kind of medicine you take depends on your type of diabetes, your schedule, and your other health conditions.
With type 1 diabetes, your pancreas does not make insulin. Insulin is a hormone that helps glucose get into your cells to give them energy. Without insulin, too much glucose stays in your blood. If you have type 1 diabetes, you will need to take insulin.
Type 2 diabetes, the most common type, can start when the body doesn't use insulin as it should. If your body can't keep up with the need for insulin, you may need to take pills. Along with meal planning and physical activity, diabetes pills help people with type 2 diabetes or gestational diabetes keep their blood glucose levels on target. Several kinds of pills are available. Each works in a different way. Many people take two or three kinds of pills. Some people take combination pills. Combination pills contain two kinds of diabetes medicine in one tablet. Some people take pills and insulin.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases