Hormone
A good example of negative feedback is with the hormone insulin. Insulin is produced by the pancreas. Insulin is released by the pancreas in response to consumption of glucose. The amount of glucose in the blood rises, and the pancreas detects the increase. It then secretes insulin into the blood. Insulin increases glucose uptake in target cells. Some glucose is used by the cells but some is also converted to and stored in the form of glycogen.  Glucose uptake by cells decreases blood glucose levels. This decrease is detected by the pancreas and in response, it stops secreting insulin in to the bloodstream. As insulin levels in the blood decrease, so does glucose uptake by cells.