Compounds for treatment of obesity

The invention relates to a construct comprising a compound targeting areas in the brain involved in the regulation of body weight and an allosteric ligand to a receptor located in the blood-brain barrier (BBB). The invention also relates to compositions and uses of such construct, for example in the prevention or treatment of overweight and obesity. Preferred compounds for regulation of body weight include GLP-1 receptor agonists (GLP-1RA), and preferred receptors located in the BBB include the transferrin receptor (TfR). Exemplary fusions and conjugates of GLP-1 RA's and anti TfR-Fab's exhibit an increased binding to brain regions expressing the GLP-1 receptor as compared to fusions or conjugates with inactive control Fab's, in particular in brain areas protected by the BBB. In vivo mice studies confirm increased reduction in food intake as well as weight loss for the active construct compared to the inactive one.