Desmopressin (dDAVP), a synthetic analog of the neurohypophyseal nonapeptide arginine vasopressin, has enhanced antidiuretic potency, markedly diminished pressor activity, and a prolonged half-life and duration of action compared to the natural hormone. Desmopressin is the treatment of choice for central diabetes insipidus and can be administered either intranasally or parenterally. A newly approved indication is treatment of mild classical hemophilia and von Willebrand's disease, in which deficient concentrations of factor VIII and von Willebrand's factor are transiently increased to levels that allow minor surgery.