At first, my pulmonologist would not give me 7% and insisted that I try 3%. They thought that 7% would be too harsh. 3% was not much better than .09% for me. I am also thought to have asthma. Finally, they agreed to 7% and I have not looked back. Within the first few minutes of nebulizing, I do cough, maybe it’s a bronchi spasm, but it helps get the gunk out. It would be a setback for me if I had to go back to 3%.