Abstract: The present invention relates to a pharmacologically active peptide hormone derivative in which the parent peptide hormone has been modified by introducing either a lipophilic substituent, W, in the N-terminal amino acid or a lipophilic substituent, Z, in the C-terminal amino acid of the parent peptide hormone or an analogue thereof, said lipophilic substituent having from 8 to 40 carbon atoms, has a protracted profile of action.

Abstract: The present invention relates to human insulin derivatives having a protracted profile of action in which the A21 and B3 amino acid residues are, independently, any amino acid residue which can be coded for by the genetic code except Lys, Arg and Cys; Phe.sup.B1 may be deleted; the B30 amino acid residue is (a) a non-codable, lipophilic amino acid having from 10 to 24 carbon atoms in which case an acyl group of a carboxylic acid with up to 5 carbon atoms is bound to the E-amino group of Lys.sup.B29 ; (b) any amino acid residue which can be coded by the genetic code except Lys, Arg and Cys, in which case a lipophilic substituent is bound to the E-amino group of Lys.sup.B29 ; or (c) deleted, in which case a lipophilic substituent is bound to the E-amino group of LyS.sup.B29 ; and any Zn.sup.2+ complexes thereof; provided that when the B30 amino acid residue is Thr or Ala, the A21 and B3 amino acid residues are both Asn and Phe.sup.B1 is present, then the insulin derivative is a Zn.sup.2 + complex.