I've been using 02 at night and I definitely sleep better and have a lot more energy during the day. The downside is that since I'm not getting up every hour or two, when I wake up in the morning, my lungs are a LOT more congested since I havent been doing as much hacking during the night. I also exercise with 02 and it makes such a big difference in my exhaustion level, during and after. I started myself on 02 when I noticed my sats were dropping to 88 at night. (yes, you can get the stuff online without a script) Finally after a MONTH I was able to get the simple sleep study at home, and it showed that during deep sleep they were in the low 80's. Good thing I was proactive, I could just visualize the little brain cells dying off in droves...............ugh!