The present invention relates to insulin derivatives which are naturally occurring insulins or analogues thereof which have a side chain attached either to the ±-amino group of the N-terminal amino acid residue of the B chain or to the µ-amino group of a Lys residue present in the B chain of the parent insulin, the side chain being of the general formula: €ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ -W-X-Y-Z wherein W, X, Y and Z are as defined in the disclosure.
