This medication is a combination of 2 drugs: metformin. It is used with a proper diet and exercise program to control high blood sugar in people with type 2 diabetes. Controlling high blood sugar helps prevent kidney damage, blindness, nerve problems, loss of limbs, and sexual function problems. Proper control of diabetes may also lessen your risk of a heart attack or stroke. metformin lower blood sugar by helping to restore your body's proper response to insulin. Metformin also decreases the amount of sugar that your liver makes and that your stomach/intestines absorb.