Review (4/5): Have realistic expectations
I used to alternate between this and Crest 3D but for budget reasons I started using cheaper toothpastes and boy did I regret it I realized how yellow my teeth had become so I sacrificed and bought Optic white and the whitening rinse. I noticed a difference in about 3 days then I added other whitening products because I was impatient. Bottom line if you only need a light lift of a shade or so the toothpaste by itself will work but if you need significant lightening you should invest in the product line toothpaste, rinse, & pen. If you're impatient add other products to your regimen. Stronger whitening gels, whitening trays and a led light may help. I don't think I'll alternate products this time because I'm very happy with the results.