Review (5/5): It worked!
I bought this as I wanted to get rid of stains and it was recommended for sensitive teeth. I had previously tried Crest white strips but found they made my teeth really hurt. Glo brightening did not make my teeth hurt. It is tough on the lips though. They provide a lip balm to use. However, the lip balm is mint flavored. Mint lip products can be really irritating. I ended up using a heavy lip product without mint with Glo. At the end of the five days of use, my teeth did whiten about three shades and I am very happy. It says it takes 8 minutes but you repeat the 8 minute treatment 4 times in a row per day. So, the full treatment is 24 minutes per day for 5 days.