Gly-Sar is widely used in biochemical research as a model dipeptide to study peptide transport mechanisms across cell membranes. It is particularly valuable in investigating the function of peptide transporters like PEPT1 and PEPT2, which are critical for nutrient absorption in the intestines and kidneys. Additionally, Gly-Sar serves as a substrate in enzymatic assays to evaluate the activity of peptidases and other enzymes involved in peptide metabolism. Its stability and simplicity make it a useful tool in drug delivery studies, where it helps in understanding how peptide-based drugs can be efficiently absorbed and distributed in the body.