Levonorgestrel
"I've had my Skyla for a week now, got it because I started experiencing migraines with aura. The insertion really does suck, no sugar coating it. I consider myself to have a pretty good pain tolerance and the pain isn't anything that would stop me from getting another one. Feels like an extremely deep, painful period cramp that kinda takes your breath away for a second. It's over very quickly though so don't let yourself get too hung up on that. I had to call in sick from severe period like cramping. Next day I woke up and felt totally fine. I've only had very light spotting after exercise otherwise nothing. Occasional period like cramping, nothing that Advil can't help. So far i'm really happy with my decision!"