DPP4 and type 2 diabetes mellitus: However, the beneficial effects of GLP‐1 were limited in clinical trials of type 2 diabetic patients due to the very short half‐life of GLP‐1, which is approximately 2–5 min, via degradation by the enzyme dipeptidyl peptidase 4 (DPP‐4) (Holst, 2019; Müller et al., 2019).