I was on advair 250/50 for about 4 years. It worked pretty well for me. My symptoms pretty much went away. I went off it about 6 months ago, and for the most part am still doing pretty good. I'm wondering how long do the residual effects of the drug stay with you? I'm talking about the desired asthma-reducing effects of the drug, not side effects. I've heard it could be up to 8 weeks. Anyone know?