Abstract: The present invention relates to the field of preventive and therapeutic medicine, in particular to peptide formulations. Provided is a pH-buffered aqueous formulation comprising oxytocin, vasopressin or an analogue thereof and at least one non-toxic source of divalent metal ions in a concentration of at least 2 mM, and the use of the formulation for the manufacture of a medicament for therapeutic and/or prophylactic treatments. Also provided is a method for treating or preventing haemorrhage in a subject in need thereof, comprising administering to said subject an effective dosage amount of an oxytocin formulation according to the invention. Further provided is a method for treating or preventing diabetes insipidus or vasodilatory shock in a subject in need thereof, comprising administering to said subject an effective dosage amount of a vasopressin formulation according to the invention.