The present invention is directed to peptide analogues of glucagon-like peptide-1, the pharmaceutically-acceptable salts thereof, to methods of using such analogues to treat mammals and to pharmaceutical compositions useful therefor comprising said analogues. A grayscale or a grayscale value is converted according to an original peak value and a converted peak value, and a total number of sustain pulses applied to the one frame is reset such that a brightness corresponding to the converted grayscale or grayscale value is set to be equal to a brightness corresponding to the original grayscale or grayscale value. The head portion is advantageously of cylindrical conformation and provided with an outer male thread for receiving and being removably coupled with the superstructure.