Recent research has suggested that the therapeutic implications of incretin hormones as combination agents in obesity, such as GLP-1 plus GIP, GLP-1 plus glucagon, GLP-1 plus GIP plus glucagon receptor agonists, GLP-1 plus amylin analogue, may have promising potential for weight loss and weight maintenance. This evidence concerns the gene GCGR and obesity due to melanocortin 4 receptor deficiency.