I have had Mirena since April 2005 and after 3-4 months of spotting I have not had a period. I love it. I don't have to worry about getting pregnant. (I have a 2.5 year old and an 11 month old) It' also ideal for me because birth control pills are not very effective due to the fact that my liver is busy with my anti-seizure medicines. Having the horomones delivered directly to my cervix makes the Mirena 99.9% effective. I haven't had any weight gain, I can breast feed without any worries, and I can't say that it has affected my libido. I Love it!