The present invention relates to improved pharmaceutical formulations, uses and methods for the oral delivery of peptide drugs with advantageously high bioavailability, safety and costeffectiveness. In particular, the invention provides a peptide drug having a molecular weight of equal to or less than 5 kDa for use as a medicament, wherein said peptide drug is to be administered orally in combination with a pharmaceutically acceptable copper salt/complex and/or a pharmaceutically acceptable zinc salt/complex and/or a pharmaceutically acceptable iron salt/complex, and with a pharmaceutically acceptable complexing agent. The invention also provides a pharmaceutical composition comprising: a peptide drug having a molecular weight of equal to or less than 5 kDa； a pharmaceutically acceptable copper salt/complex and/or a pharmaceutically acceptable zinc salt/complex and/or a pharmaceutically acceptable iron salt/complex； and a pharmaceutically acceptable complexing agent.
