Why Native GLP-1 Fails in the Body

Native GLP-1 is powerful — and almost useless as a drug. The enzyme DPP-4 chops it apart within about two minutes of release. That's why every therapeutic GLP-1 (liraglutide, semaglutide, tirzepatide) is an engineered analog built to resist DPP-4.

Understanding this single limitation is the key to understanding the entire GLP-1 drug class — from DPP-4 inhibitors (which protect endogenous GLP-1) to long-acting injectable analogs. Members new to metabolic research often start here.