Insulin is a hormone that is produced by the pancreas and is released into the bloodstream to control the level of glucose in the blood. When the blood glucose concentration is too high, the pancreas secretes a hormone known as Insulin. Insulin travels into the bloodstream until it reaches its target organ, which is the liver. Here, it causes cells to take up glucose from the blood. Also, it stimulates liver and muscle cells to take up the excess glucose and convert its into glycogen; a glucose storage molecule. As a result, the concentration of glucose in the blood is reduced to within the normal range, a process known as negative feedback.