I intended this as a joke, although it was true; he left the room the first time I turned it on. But last night he laid down right beside me and purred for the whole 25 minutes. I covered my nose! Not sure if the light might be bad for him to look at. If anything, my sleep has been worse since starting this. I haven't been perfect about controlling other things that might affect sleep (cocoa, dairy), so it's not a perfect test. But I'm going to switch to the morning for a few days and see if it's energizing for me, while I clean up my diet.