Wow, I've never heard that about Revolution. I've never used it though...I have a paranoia about using a heartworm preventative that goes on the skin. I know it works just as well, but I don't know...I like knowing my dog received the medication and that I didn't mess up in applying it! I don't know. Maybe I'm just weird! Personally I like Interceptor. That's what my dog is on. I like the fact that it deworms for hooks, rounds, and whips too.