Insulin is a protein hormone that plays a critical role in regulating the concentration of glucose in the bloodstream. Produced primarily by specialized cells within the pancreas, it acts as a key metabolic regulator, enabling peripheral tissues, particularly muscle and adipose tissue, to absorb glucose from the blood. When blood sugar levels rise following a meal, insulin is released to facilitate the uptake of glucose by cells, where it can be used for energy or stored for later use. Proper insulin function is essential for maintaining glucose homeostasis, the stable balance of sugar required for normal cellular function and overall metabolic health. Dysregulation of this hormone is associated with conditions characterized by chronically elevated blood glucose levels.