where is leptin produced and what is it's function? leptin is a protein produced by adipose (fat) cells. it signals adequate fat storage and leads to a reduction in hunger and eating. leptin is produced by the small intestine in response to food and functions to reduce hunger. leptin is a hormone made by the liver. it stimulates hunger and eating in response to reduce nutrient availablity. leptin is produce by the pituitary gland and functions to reduce overeating by promoting satiety.