After I was lead back to the room, they got me comfortable on the chair & they gave me a mask to breath in whatever it was that made me go to sleep. (just the mask, no needles or anything else) It took about 10 minutes or so, they just tell you to breath it in, and next thing I knew I was waking up as they were taking me somewhere to rest for a few minutes after it was done. Coming out of it, I was a little disoriented and sleepy, but that was it for me. I just dozed on the car ride back home.