GLP1R and obesity due to melanocortin 4 receptor deficiency: The US Food and Drug Administration (FDA) approval for weight management of the first-generation glucagon-like peptide 1 (GLP-1) receptor agonists (RA) liraglutide in 2014 followed by two more potent GLP-1 based therapies (GBT), semaglutide (GLP-1RA) in 2021 and tirzepatide (dual GLP-1/gastric inhibitory polypeptide RA) in 2023 [8,9] have led to a paradigm shift in the management of health conditions related to obesity.