Linagliptin (Trajenta) is a selective inhibitor of dipeptidyl peptidase-4, an enzyme that degrades two incretin hormones, GLP-1 ("Glucagon-Like Peptide-1") and GIP ("Glucose-dependent Insulinotropic Polypeptide"). As other molecules belonging to this pharmacological class, linagliptin improves blood glucose control of type 2 diabetic patients, without increasing hypoglycaemic risk, without promoting weight gain and with a good clinical and biological tolerance profile. Both efficacy and safety have been demonstrated in randomized controlled trials as monotherapy or in combination with other glucose-lowering agents, independent of demographic or clinical patient's characteristics. The pharmacokinetics specificity of linagliptin comprises its biliary excretion, with low hepatic metabolism (no drug-drug interactions) and, in contrast to other gliptins, its negligible renal elimination. Because of these favourable properties, linagliptin may be used without dose adjustment (5 mg once a day) in patients with renal impairment, as well as in elderly people.