Levonorgestrel
"I had no noticeable side effects at all.  I did have some cramping the first month that was slight.  I took some ibuprofen when it bothered me.  I spotted for about 3 weeks and had one small period.  Then my periods stopped.  Once in a while I get a little pink speck on toilet paper, none on my underwear.  It is wonderful having birth control and not worrying about pills, periods, mood swings, or headaches.  It is the best birth control ever!  I also like the shorter commitment and the extra low hormone content.  No weight gain.  I love that is pretty much stopped my PMS completely.  I notice a slight mood change once a month-ish and it used to be really bad for me.  It is a big improvement.  I am 42 and I plan to stay on this until menopas"