Methods for administering leuprolide by inhalation

Phospholipid based particulate compositions of leuprolide and methods of pulmonary administration via dry powder inhalers are provided. The leuprolide particulate compositions are particularly suited to the treatment of diseases and disorders associated with elevated or inappropriate levels of sex-hormone or that benefit from inhibition of gonadotropin secretion, such as prostate cancer, endometriosis, and central precocious puberty. The leuprolide compositions for inhalation are engineered to be highly dispersible and provide rapid absorption of the active agent so delivered, as well as to exhibit substantially independent emitted doses and lung deposition as functions of device resistance and inspiratory flow rates, respectively.