I have tried many other brands of toothpaste tablets and have had too much sensitivity for them to work for me. I wanted to try these to upgrade my children from the tablets they were using but upping the amount of fluoride. I decided to try them... - I love the taste! So fresh and fruity. My kids love them too. - I have had no issues with sensitivity at all.... after years of having to use specialist toothpaste. - I have had many allergies to different toothpaste in the past. No allergic reactions at all. in short we have found our family's new toothpaste tablets. the only downside is that they are very crumbly. Lots were broken in the tin. However that is what also makes them so lovely, as they melt into a paste so easily, so much better than others that we have to chew on for ever. I don't mind the breakage, but it might bother others a bit. All in all, I am sooooo happy to have found these!