I have been on it for two weeks. The biggest thing I notice: nothing! By that I mean within two days of starting the drug, I am no longer reminded by extreme shortness of breath all day long that I have a lung disease. For most of the day, I do not feel sick. When I nebulize saline or hammer uphill on the bicycle, I am not wheezing, and if I cough, it is productive, not stuck in my throat. On the bicycle, my heart rate was jumping to 200 when I went up a hard hill (I had a full cardiac workup a month ago‚ echocardiogram and heart catheterization, and all was normal with that system.) Now I have a hard time getting it to 160, and my VO2 max has gone up to 36 for the first time this year. Morning after waking up and lying down at night are rocky for about a half hour, but otherwise I feel great. I still have to do all the things I was doing before, but this has made a world of difference for me.