The present invention relates to use of GLP-1 or a related molecule having GLP-effect for the manufacture of a medicament for preventing or treating diabetes in a mammal. The amount and timing of administration of said medicament are subsequently reduced to produce a "drug holiday". Practice of the invention achieves effective therapy without continuous drug exposure and without continuous presence of therapeutic levels of the drug. The invention also discloses a method of treating diabetes and related disorders in a mammal by administering glucagon like peptide (GLP-1) or a related molecule having GLP-1 like effect and thereby providing a therapeutically effective amount of endogenous insulin.
