We're sorry you experienced sensitivity. Whitestrips are very safe when used as directed, but like any whitening product that contains peroxide, temporary sensitivity may develop. Although harmless, this can be uncomfortable, so we'd like to share some tips for preventing sensitivity. First, while using Whitestrips don't brush more than twice a day, and brush gently using a soft bristled brush. Using a mild toothpaste such as Crest Cavity Protection can also help. Another tip is to use the strips over a longer period of time by waiting a day between applications, or alternating between using an upper and lower strip. While whitening may take longer, but you'll still have the same overall whitening effect. If you still experience significant irritation, then we recommend you stop use and consult your dentist. We'd like to talk with you in more detail to ensure you're having the best experience possible. Please give our Crest Team a call at 1-800-395-8423 from 9AM -- 6PM EST Monday–Friday. We're always glad to help!

We're so sorry you developed sensitivity and hope you're feeling better. We're glad to let you know this is temporary and is not harmful, but still we know it can be uncomfortable. We appreciate you taking the time to let us know, so we can share your experience with our Safety Team. We know with any teeth whitening product containing peroxide, sensitivity or soreness may temporarily develop. The good news is, you may be able to continue using the product while reducing -- or even eliminating -- the sensitivity. Below are some tips that should help, but if you still experience significant sensitivity, we recommend you stop using Crest Whitestrips. 1. Try using only 1 Whitestrip per day rather than 2. Don't brush your teeth right before using a Whitestrip. 3. While whitening, use a soft bristled toothbrush and a mild toothpaste like, Crest Cavity Protection, and don't brush too hard. 4. Limit brushing to twice a day. 5. Stop using the Whitestrips for 2 to 3 days; then resume once per day. We hope these suggestions relieve your sensitivity. We'd like to gather more information for our Safety Team. so please call us at 1-800-395-8423.