birth control
"I've been using it for 4 years. Never had a problem. I never had side effects until I got off it for a couple months and then went back on. I got some nausea and vomiting, but I've always had a sensitive stomach so it had to do with a combination of things. All in all, it's the best. I switch from butt cheek to butt cheek each week. It's less likely to fall off if your sitting on it."