Ved at hæmme DPP- 4- enzymet øger sitagliptin niveauerne for de to kendte aktive inkretinhormoner, glucagonlignende peptid 1 (GLP- 1) og glucoseafhængigt insulinotropt polypeptid (GIP).
By inhibiting the DPP-4 enzyme, sitagliptin increases the levels of two known active incretin hormones, glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP).