Hi, I am suffering from chronic urticaria for 6 months. My doctor told me that xolair can really help me so I've taken xolair a week ago, 300 milligrams. So far I can't see any change and it makes me really nerves. I have taken the shot one week ago, and im 14. Does anybody have taken xolair and can tell me how much time it took for it to work? Any experience would help me !!