I was a bit skeptical when I bought the mouth guard, but I was pleasantly surprised at how great a product it is! I had to use it in hot water a couple of times to get it to fit me. I had to cut a piece off the edge so it wouldn't press on my gums. I've worn it almost every night since I bought it. You can see the difference right away if I forget to put it on at night. The mouth guard has clearly reduced bruxism, jaw pain, and headaches. I recommend trying it out!