GLP1R and obesity due to melanocortin 4 receptor deficiency: Molecules of novel therapeutic classes have emerged, such as tirzepatide, the first dual glucose-dependent insulinotropic polypeptide/glucagon-like peptide-1 receptor agonist (GIP)/GLP-1 RA), which has recently demonstrated a body weight reduction exceeding 20% in people with obesity, coupled with improved cardiometabolic measures (94).