This is a product that is very effective. It truly works. However, if you have sensitive teeth, I wouldn’t recommend trying these. I have sensitive teeth and after 10 minutes, the whitening strips have me in tears. They also leave my teeth even more sensitive after. The box does provide a warning so I knew I was taking a risk by trying these. This is a great product but if you have sensitive teeth, I would just steer clear. I use the the 3D White Toothpaste and mouthwash morning and night and that really keeps my teeth white without the pain of the strips. This just wasn’t for me but if you don’t have sensitivity issues, DEFINITELY try them!