GKA50 quarterhydrate is a potent glucokinase activator with an EC50 value of 33 nM. GKA50 quarterhydrate is a glucose-like activator of β-cell metabolism in rodent and human pancreatic islets and a Ca2+-dependent regulator of insulin secretion. quarterhydrate stimulates insulin secretion in mouse islets and significantly reduces blood glucose in high-fat-fed female rats.