Ghrelin is a hormone produced mainly in the stomach that plays a key role in regulating appetite. Often referred to as the "hunger hormone," it signals the brain to stimulate feelings of hunger, prompting individuals to eat. Ghrelin levels typically rise before meals and decrease after eating. In addition to its role in appetite regulation, ghrelin also influences energy balance and metabolism. It can affect how the body stores fat and uses energy, making it an important factor in weight management. Research on ghrelin may provide insights into obesity and related health issues.