A condition in which cells in muscle, fat, and liver respond poorly to insulin’s signal to absorb glucose from the bloodstream. The pancreas compensates by producing more insulin, maintaining normal blood sugar temporarily—but this compensation eventually fails, leading to elevated blood glucose and type 2 diabetes.

Insulin resistance is central to metabolic syndrome, type 2 diabetes, and cardiovascular disease. GLP-1 receptor agonists (semaglutide, tirzepatide, liraglutide) improve insulin sensitivity through multiple mechanisms including weight loss, direct pancreatic effects, and reduced hepatic glucose production. This is why these compounds produce metabolic benefits beyond simple weight reduction—they address the underlying insulin resistance that drives the disease process.