INTRODUCTION: Insulin therapy is a mainstay for treatment of diabetes mellitus; however, many barriers to insulin exist. Insulin human inhalation powder (technosphere insulin) is a new FDA-approved alternative to subcutaneous bolus insulin. AREAS COVERED: This is an overview of technosphere insulin (TI). Pharmacokinetics, clinical efficacy, safety and tolerability are discussed. EXPERT OPINION: TI is more quickly absorbed than subcutaneous insulin therapies and has a shorter duration of action. It appears to be noninferior compared with subcutaneous insulin regimens, and is associated with less hypoglycemia. Thus, it may serve as an alternative insulin agent in patients reluctant to administer multiple subcutaneous injections of insulin daily or in patients who experience late postprandial hypoglycemia with subcutaneous insulin. Cough is the most common side effect, but tends to be mild and transient. A small decrease in the forced expiratory volume has been demonstrated, but does not appear to progress and is reversible. Patients should have periodic pulmonary function tests. TI is contraindicated in patients with chronic lung disease. The long-term risk of lung cancer is being monitored but at this point does not appear to be higher than the expected incidence of lung cancer in this population.