I've done a few cycles of Cardarine -- 'SARM' is sort of a misnomer, though. It's not a SARM; it's a PPAR activator, but a lot of people tend to lump it in with the SARMs for some reason or another. It doesn't actually impact hormone levels, so it shouldn't have any effect on birth control at all. (Anyone can feel free to correct me if I'm wrong, haha!) Personally, I enjoyed it. I feel like it kept me substantially leaner while I was trying to build up some mass. The endurance boost was a bonus, but overall, it's a good add-on to any stack.