After a few days wearing it, I hardly notice it. Sleep just fine with it. Im like Stephan Curry with that mouthpiece. Flipping it around and chewing on it. Played football for 12 years straight and boxed for the college team so I pretty much was wearing a mouthpiece my whole life . Its no big deal plus I like working out with it. I can grit down like a damn pitbull now. haha