Which diabetes drug is least likely to cause weight gain?

Liraglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that is generally associated with weight loss rather than weight gain in patients with type 2 diabetes. This mechanism operates through multiple pathways, including delaying gastric emptying and promoting satiety, which can reduce overall calorie intake. These effects not only help in controlling blood glucose levels but also assist patients in losing weight or preventing weight gain, making liraglutide a favorable option for individuals who are concerned about managing their weight alongside their diabetes.

In contrast, other diabetes medications listed can lead to weight gain. For instance, pioglitazone, a thiazolidinedione, can cause fluid retention and increased adiposity, contributing to weight gain. Repaglinide, which is a meglitinide, stimulates insulin secretion from the pancreas and can also result in increased appetite and caloric intake. Insulin glulisine, a rapid-acting insulin, can lead to weight gain as well since insulin can promote fat storage and possibly increase appetite in some patients.

Thus, among the options, liraglutide stands out as the agent least likely to cause weight gain, making it a popular choice for managing both diabetes and weight concerns.