Insulin therapy replaces the insulin the body would normally make. People with type 1 diabetes must take insulin every day. People with type 2 diabetes need to take insulin when other treatments and medicines fail to control blood sugar levels.

It regulates the movement of glucose from blood into cells. Insulin lowers blood glucose by stimulating peripheral glucose uptake primarily by skeletal muscle cells and fat, and by inhibiting glucose production and release by the liver.

All people who have type 1 diabetes and some people who have type 2 diabetes need to take insulin to help control their blood sugar levels. The goal of taking insulin is to keep your blood sugar level in a normal range as much as possible. Keeping blood sugar in check helps you stay healthy.