Copper
"I didn't rate this as a 10 or higher because I just got it put in about 3 hours ago. I had the Mirena for about 6 weeks but I wanted to change it to the non-hormonal paraguard plus it's effective for 10 years! I have 2 kids my youngest being 4 months I wanted the IUD because I do not want anymore kids. The procedure was painless for me except for a sting/pinch, maybe for me it was painless because of previous births and I also was spotting which the doctor said would make it easier. I had minor cramping for about an hour afterwards I will write again in a month or so to say how it's been. Hopefully it will be good :)"