This paper describes development and evaluation of an inhalable dry-powder formulation containing peptide YY3–36 [PYY(3–36)], which has shown efficacy in appetite suppression when dosed by injection. The systemic pharmacokinetics of PYY3-36 were evaluated when delivered by intraperitoneal and subcutaneous injection and inhalation before selecting doses for an appetite-suppression pharmacodynamic study. The resulting pharmacokinetic data proved valuable in pharmacodynamic dose selection for inhalation delivery of the peptide. In addition, engineered PYY(3–36):Dextran T10 particles delivered to the respiratory tract show promise as a noninvasive therapeutic for appetite suppression.