birth control
"First off, let me disclaim that while I rated this a ten in EFFECTIVENESS, that doesn't mean it was all great. It obliterated my sex drive. A few months into using it, I was completely uninterested in being with my partner. Sex was actually painful. I've been off it for about three weeks now and I'm back in full swing. 

I haven't gotten pregnant while using this without a condom, etc. So while it was effective, it was  kind of useless for preventing pregnancy since I never wanted sex while on it anyway.

I went on it initially for period cramps. My periods would last 2-4 weeks at a time and were awful. So painful. This brought them down to 1-1.5 weeks with what I am assuming to be normal cramping. I could function during my cycles on this."