I have used Clariton for years, and it has stopped working for me. I decided to try Zyrtec this year, and boy did it work. I took two for two straight days and I stopped. I stopped because it cured me for a month and I got scared because it seemed very strong. It makes me feel super relaxed (that got me scared) and sort of happy. I might just have to take half? but i'm sure that is not recommended.