Since metformin in T2DM is the first-line treatment, GLP-1 analogues, and therefore liraglutide, are used when metformin is intolerant or contraindicated and when the target HbA1c level has not been achieved within 3 months or HbA1c is more than 1.5% above the target threshold. Here, GCG is linked to type 2 diabetes mellitus.