I started using the HS (3%)while in was still in the hospital about a month and a half ago. I noticed the difference right away. After i was done inhaling it, i tried to relax and take a nap, but i had so much loosened mucus just wanting to be coughed out, so i got quite a bit out. I was not used to having to cough so much out after using only Pulmozyme, so i knew it had to be the HS.