Review (5/5): Nothing better
I love this system. I have an older unit and it's worked for years. I have extremely sensitive and somewhat crooked teeth, so other whitening devices either hurt really bad and/or don't stay on (strips). Glo DOES NOT HURT. I cannot stress that enough. The only time I've had any issues is when I've accidentally gotten some of the gel on my gums. It'll hurt during the session and turn white but go away by the next morning. However, just use a Q-tip to wipe off any gel that gets on your gums and you'll never have an issue. My teeth are definitely on the whiter side to begin with, but with Glo, twice I've gotten to the whitest natural shade possible, B1, before getting permanent crowns (so the dentist has taken my shade and told me I'm B1). Would highly recommend.