The invention provides specific GLP-1 analogs fused to specific IgG4-Fc derivatives. These fusion proteins have an increased half-life, decreased immunogenicity, and reduce effector activity. The fusion proteins 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.