An anorexigen is a peptide neurotransmitter released by the arcuate nucleus that chemically suppresses appetite. These peptides are responsible for feelings of satiety and fullness causing the desire for food to go away. One anorexigen is called CART (cocaine and amphetamine-regulated transcript) and it inhibits the desire to eat. When cocaine or amphetamines are given to lab animals their levels of CART increases - this is what is responsible for the appetite suppressing qualities of these drugs. When an organism is food-deprived their CART levels decrease which makes them want to eat. When they are satiated and full of food CART levels increase and the desire for food decreases.