The invention provides GLP-1 compounds coupled to at least one polyethylene glycol molecule or derivative thereof, resulting in a biologically active peptide with an extended half-life and a slower clearance when compared to that of unPEGylated peptide. These PEGylated GLP-1 compounds and compositions are useful in treating diabetes, obesity, irritable bowel syndrome and other conditions that would be benefited by lowering plasma glucose, inhibiting gastric and/or intestinal motility and inhibiting gastric and/or intestinal emptying, or inhibiting food intake.