We're glad you love your whiter smile, and would like to share some prevention tips if you're experiencing sensitivity. Our Whitestrips are very safe when used as directed, but like any whitening product that contains peroxide, temporary sensitivity may develop. First, don't brush too hard and or more than twice a day while using whitestrips. Also, avoid medium to hard bristled toothbrushes after whitening your teeth and instead choose a soft bristled brush. Trying a different toothpaste such as Crest Cavity Protection can also sometimes be helpful, as ingredients in some toothpastes can cause gum discomfort. If significant gum irritation develops, try using Crest Whitestrips only once per day, rather than two times per day or stop using for 2-3 days then resume once per day. Usually if you follow these tips, it should stop this problem from happening. If you still experience significant irritation, then we recommend you stop use. If you need any further assistance or have questions, please give our Crest Team a call at 1-800-395-8423 from 9AM -- 6PM EST Monday–Friday. We're always glad to help!

All of our products are thoroughly evaluated to make sure they're safe when used as directed, so we're sorry to hear about your experience, and we certainly hope you're feeling better. As with any teeth whitening product containing peroxide, when gel comes in contact with gums, it can cause temporary whitening, sensitivity or soreness. We recommend that you stop using the Whitestrips for a few days, until the gum irritation goes away, then start again after a few days by wearing only one upper and one lower strip a day. This should minimize future gum whitening or irritation. Since your safety is our top priority, we'd like to learn more to share with our Safety Team and provide some additional tips, so please give us a call at (800) 395-8423.