GCG and Alzheimer disease: Glucagon like peptide 1 (GLP1) agonists have been shown to offer neuroprotection (Perry et al., 2002, 2007), reverse brain IR (Bomfim et al., 2012; Talbot and Wang, 2014), decrease Aβ and tau levels and deposits (Li et al., 2010; McClean et al., 2011), and decrease tau hyper-phosphorylation (Xu et al., 2015) in multiple cellular and animal models of AD.