In recent years, a major breakthrough has been made in the treatment of obesity in non-pregnant adults with the advent of incretin-based drugs such as semaglutide (marketed as Ozempic and Wegovy), which mimic endogenous glucagon-like peptide 1 (GLP-1) action (see Table 1 for a list of drugs mentioned in this review). Here, GCG is linked to obesity due to melanocortin 4 receptor deficiency.