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. We understand this can be uncomfortable and have some tips for preventing sensitivity. 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, you'll still have the same overall whitening effect. If you continue to experience significant irritation, then we recommend you stop use. 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!

Thank you for leaving your review, Jenny! This feedback is greatly appreciated, and we're sorry to learn you experienced sensitivity that prevented you from completing the whitening regimen. Your report will be shared with our Health & Safety Team, as they ensure that Crest Whitestrips perform brilliantly and are 100 percent safe when the usage directions are followed. Would you mind giving us a call at (800) 395-8423? We'd like to gather further information on your product to share with our team so they have a full report. We'll also be glad to suggest a different whitening product that will provide great whitening results but without the sensitivity.