I am incredibly impressed with the Optic White Toothpaste and Whitening Pen. I could definitely see a difference in colour on my teeth within three days. I experienced no sensitivity when using the products. I am impressed at how affordable both products are for the amazing results you get. I will highly recommend this product to family and friends. I am convinced to not buy any other products as I am loving the results so much. Thanks to Colgate I am now super confident in sharing my bright white smile with everyone.