The organ responsible for producing insulin in the human body is the pancreas. This gland functions as both an exocrine and endocrine organ. In its endocrine role, it releases insulin directly into the bloodstream, where it plays a critical role in regulating blood sugar levels. Insulin facilitates the uptake of glucose by cells, allowing the body to use it for energy or store it as glycogen in the liver and muscles. Dysregulation of insulin production can lead to conditions such as diabetes mellitus, necessitating careful management of blood glucose levels.