GCG and obesity due to melanocortin 4 receptor deficiency: While the precise mechanisms behind the hypophagic effects of GLP-1 RAs are still not fully understood, GLP-1 RAs like liraglutide or semaglutide, as well as tirzepatide, a GLP-1/GIP RA, have been authorized for weight loss as an adjunct therapy to lifestyle interventions in adults with obesity (body mass index (BMI) of ≥ 30 mg/m2) or adults with overweight (BMI ≥ 27 mg/m2 but ≤ 30 mg/m2) who have at least one weight-related health problem.