I had it done at the dermatologists office. First...
I had it done at the dermatologists office. First and second treatments were set at 50 strength and I was numbed for about a half hour to 45 minutes. It was painful but tolerable. People with low pain threshold would not be able to take it. I am usually very tolerant of pain. I was red and swollen up to five days and then was peeling for several weeks. I didn't see much results at all. When I went for the second treatment I was told results would be dramatic after the third treatment.
The other day I had third treatment with one hour numbing and setting of machine at 55. It was EXCRUCIATING!! I told them I didn't see much results up to then and was told now that I would see full effect after six months as the skin needs to make new collagen and that takes months. My face now is swollen as it was just a couple of days ago.
It is very expensive at over $1200 for face and neck for each treatment. So far I am disappointed. I did it for wrinkles and just to improve texture of skin. If there is improvement, it is extremely subtle. I will report further after a few months. I go back for fourth treatment next month. I hope it is true that there is much improvement after months of building new collagen as it is very expensive.