Items didn't come with directions for bleaching the teeth. So after researching the reviews and the website, I found some directions. I kept them in my mouth at 5 minutes each day for 2 consecutive weeks. It did sting my gums as warned, but this was expected. But after the two weeks they didn't seem to work. I didn't want to do it any longer if I didn't see progress. Also these were gels inserted in generic tubes. They didn't have any expiration date or use by date, so I wasn't sure if they were old. It also didn't have any warnings on what not to do and what to do.