Levonorgestrel
"I've had the Mirena for 5 years. I'm having it takin out next month. I've really enjoyed having this birth control. For one it was very effective and I didn't have to remember to take a pill. The only thing I have bad to say about the Mirena is it did cause cyst which was very painful at times and as I've read all the reviews not one person mentioned discharge. It causes you to "leak". Its perfectly normal.  But to me was gross. And it was a lot! I can say my sex drive has decreased in the last year to where I don't want it at all. Other than that it has been great! Getting it put in didn't really hurt I just felt pressure.  Hope this helps!"