I also have never been able to get it so it doesn't leak. I will make sure it's popped open and that there is a seal, but I still leak. This has caused me not to use either cup much. And for those of you that talk about the cup making your cramps better, I seem to have the opposite issue; my cramps seem about ten times worse with a cup in there.
I want so much for this to work, because tampons rub me raw, on top of being inconvenient when going to the girls room, and I go through a super plus tampon in less than an hour during the first few days of my period. Any ideas?